Gradient boosting, using H2O

Function Works
tidypredict_fit(), tidypredict_sql()
tidypredict_test()
parsnip

How it works

tidypredict supports H2O gradient boosting models (GBM) fitted through the parsnip package with the "h2o_gbm" engine of boost_tree(), which is provided by the agua package. Both regression and classification are supported.

library(parsnip)
library(agua)

model <- boost_tree(mode = "regression", trees = 10) |>
  set_engine("h2o_gbm") |>
  fit(mpg ~ wt + cyl + hp, data = mtcars)

Under the hood

An H2O model is a handle into a running H2O cluster. tidypredict pulls each boosted tree from the cluster with h2o::h2o.getModelTree() and turns it into a nested dplyr::case_when() statement. The individual tree contributions are added together (along with the model’s initial value) to form the Tidy Eval formula. Because the trees live in the cluster, an active h2o.init() connection is required.

tidypredict_fit(model)
#> 20.090625 + (case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ 
#>     case_when(wt < 1.7250888 ~ 3.0928125, .default = 4.1428123), 
#>     .default = case_when(wt < 2.1698422 ~ case_when(wt < 2.0377436 ~ 
#>         2.1628125, .default = 1.7728126), .default = 3.6928124)), 
#>     .default = case_when(cyl < 7 ~ case_when(wt < 3.326375 | 
#>         is.na(wt) ~ case_when(hp < 102.5 ~ case_when(wt < 3.1730468 | 
#>         is.na(wt) ~ case_when(hp < 96.5 ~ 0.81281245, .default = 0.4228125), 
#>         .default = 1.2928125), .default = case_when(hp < 141.5 | 
#>         is.na(hp) ~ case_when(cyl < 5 ~ 0.39281252, .default = 0.3128125), 
#>         .default = -0.1171875)), .default = case_when(wt < 3.4495606 ~ 
#>         -0.4771875, .default = -0.5971875)), .default = case_when(wt < 
#>         4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ 
#>         case_when(hp < 164 ~ case_when(wt < 3.4846094 ~ -1.4671875, 
#>             .default = -1.3771875), .default = case_when(hp < 
#>             177.5 ~ -0.3421875, .default = -1.1371875)), .default = case_when(hp < 
#>         254.5 ~ case_when(wt < 3.7039063 ~ -1.7371875, .default = -2.0371876), 
#>         .default = case_when(wt < 3.379375 ~ -1.2871876, .default = -1.5271875))), 
#>         .default = case_when(hp < 224.5 | is.na(hp) ~ -2.9071875, 
#>             .default = -1.6171875)))) + case_when(wt < 2.2596803 ~ 
#>     case_when(wt < 1.8848817 ~ case_when(wt < 1.7250888 ~ 2.1649687, 
#>         .default = 2.8999689), .default = case_when(wt < 2.1698422 ~ 
#>         case_when(wt < 2.0377436 ~ 1.513969, .default = 1.2409687), 
#>         .default = 2.5849686)), .default = case_when(cyl < 7 ~ 
#>     case_when(wt < 3.326375 | is.na(wt) ~ case_when(hp < 102.5 ~ 
#>         case_when(wt < 3.1730468 | is.na(wt) ~ case_when(hp < 
#>             96.5 ~ 0.568969, .default = 0.29596883), .default = 0.9049686), 
#>         .default = case_when(hp < 141.5 | is.na(hp) ~ case_when(wt < 
#>             3.0383594 | is.na(wt) ~ 0.210969, .default = 0.298969), 
#>             .default = -0.08203148)), .default = case_when(wt < 
#>         3.4495606 ~ -0.3340313, .default = -0.41803104)), .default = case_when(wt < 
#>     4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ case_when(hp < 
#>     164 ~ case_when(wt < 3.4846094 ~ -1.0270313, .default = -0.9640314), 
#>     .default = case_when(hp < 177.5 ~ -0.23953135, .default = -0.79603136)), 
#>     .default = case_when(hp < 254.5 ~ case_when(wt < 3.7039063 ~ 
#>         -1.2160312, .default = -1.4260314), .default = case_when(wt < 
#>         3.379375 ~ -0.9010315, .default = -1.0690315))), .default = case_when(hp < 
#>     224.5 | is.na(hp) ~ -2.035031, .default = -1.1320314)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 1.5154783, .default = 2.0299783), .default = case_when(wt < 
#>         2.1698422 ~ case_when(wt < 2.0377436 ~ 1.0597781, .default = 0.8686781), 
#>         .default = 1.8094782)), .default = case_when(cyl < 7 ~ 
#>         case_when(wt < 3.326375 | is.na(wt) ~ case_when(hp < 
#>             102.5 ~ case_when(wt < 3.1730468 | is.na(wt) ~ case_when(hp < 
#>             96.5 ~ 0.39827806, .default = 0.20717812), .default = 0.6334781), 
#>             .default = case_when(hp < 141.5 | is.na(hp) ~ case_when(cyl < 
#>                 5 ~ 0.21167804, .default = 0.1468781), .default = -0.0574221)), 
#>             .default = case_when(wt < 3.4495606 ~ -0.23382169, 
#>                 .default = -0.29262152)), .default = case_when(wt < 
#>         4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ 
#>         case_when(hp < 164 ~ case_when(wt < 3.4846094 ~ -0.7189221, 
#>             .default = -0.67482203), .default = case_when(hp < 
#>             177.5 ~ -0.1676722, .default = -0.5572218)), .default = case_when(hp < 
#>         254.5 ~ case_when(wt < 3.7039063 ~ -0.8512216, .default = -0.9982221), 
#>         .default = case_when(wt < 3.379375 ~ -0.63072205, .default = -0.7483223))), 
#>         .default = case_when(hp < 224.5 | is.na(hp) ~ -1.4245218, 
#>             .default = -0.7924223)))) + case_when(wt < 2.2596803 ~ 
#>     case_when(wt < 1.8848817 ~ case_when(wt < 1.7250888 ~ 1.0608349, 
#>         .default = 1.420985), .default = case_when(wt < 2.1698422 ~ 
#>         case_when(wt < 2.0377436 ~ 0.7418446, .default = 0.60807496), 
#>         .default = 1.2666345)), .default = case_when(cyl < 7 ~ 
#>     case_when(wt < 3.326375 | is.na(wt) ~ case_when(hp < 102.5 ~ 
#>         case_when(wt < 3.1730468 | is.na(wt) ~ case_when(hp < 
#>             96.5 ~ 0.2787949, .default = 0.14502469), .default = 0.44343463), 
#>         .default = case_when(hp < 141.5 | is.na(hp) ~ case_when(wt < 
#>             3.0383594 | is.na(wt) ~ 0.09713482, .default = 0.16521503), 
#>             .default = -0.040195312)), .default = case_when(wt < 
#>         3.4495606 ~ -0.16367513, .default = -0.20483504)), .default = case_when(wt < 
#>     4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ case_when(hp < 
#>     164 ~ case_when(wt < 3.4846094 ~ -0.5032456, .default = -0.47237548), 
#>     .default = case_when(hp < 177.5 ~ -0.11737026, .default = -0.39005503)), 
#>     .default = case_when(hp < 254.5 ~ case_when(wt < 3.7039063 ~ 
#>         -0.5958553, .default = -0.69875544), .default = case_when(wt < 
#>         3.379375 ~ -0.4415054, .default = -0.5238258))), .default = case_when(hp < 
#>     224.5 | is.na(hp) ~ -0.9971653, .default = -0.55469537)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.74258435, .default = 0.9946897), .default = case_when(wt < 
#>         2.1698422 ~ case_when(wt < 2.0377436 ~ 0.51929134, .default = 0.42565268), 
#>         .default = 0.8866443)), .default = case_when(cyl < 7 ~ 
#>         case_when(wt < 3.326375 | is.na(wt) ~ case_when(hp < 
#>             102.5 ~ case_when(wt < 3.1730468 | is.na(wt) ~ case_when(hp < 
#>             96.5 ~ 0.19515634, .default = 0.1015171), .default = 0.3104045), 
#>             .default = case_when(hp < 141.5 | is.na(hp) ~ case_when(cyl < 
#>                 5 ~ 0.11903412, .default = 0.06686634), .default = -0.028136672)), 
#>             .default = case_when(wt < 3.4495606 ~ -0.11457253, 
#>                 .default = -0.1433843)), .default = case_when(wt < 
#>         4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ 
#>         case_when(wt < 3.8098438 | is.na(wt) ~ case_when(wt < 
#>             3.7571313 | is.na(wt) ~ -0.20328303, .default = -0.6030386), 
#>             .default = case_when(wt < 3.9561818 ~ -0.007159081, 
#>                 .default = -0.24303864)), .default = case_when(hp < 
#>         254.5 ~ case_when(wt < 3.7039063 ~ -0.41709858, .default = -0.48912886), 
#>         .default = case_when(wt < 3.379375 ~ -0.30905378, .default = -0.36667785))), 
#>         .default = case_when(hp < 224.5 | is.na(hp) ~ -0.69801563, 
#>             .default = -0.3882868)))) + case_when(wt < 2.2596803 ~ 
#>     case_when(wt < 1.8848817 ~ case_when(wt < 1.7250888 ~ 0.51980907, 
#>         .default = 0.69628274), .default = case_when(wt < 2.1698422 ~ 
#>         case_when(wt < 2.0377436 ~ 0.36350405, .default = 0.29795665), 
#>         .default = 0.620651)), .default = case_when(cyl < 7 ~ 
#>     case_when(wt < 3.326375 | is.na(wt) ~ case_when(hp < 102.5 ~ 
#>         case_when(wt < 3.1730468 | is.na(wt) ~ case_when(hp < 
#>             96.5 ~ 0.1366095, .default = 0.07106209), .default = 0.21728335), 
#>         .default = case_when(hp < 141.5 | is.na(hp) ~ case_when(wt < 
#>             3.0383594 | is.na(wt) ~ 0.04271759, .default = 0.0955909), 
#>             .default = -0.01969551)), .default = case_when(wt < 
#>         3.4495606 ~ -0.08020077, .default = -0.100368805)), .default = case_when(wt < 
#>     4.660125 | is.na(wt) ~ case_when(hp < 211 | is.na(hp) ~ case_when(hp < 
#>     164 ~ case_when(wt < 3.4846094 ~ -0.2912867, .default = -0.26967773), 
#>     .default = case_when(wt < 3.7525 ~ -0.004113865, .default = -0.19908859)), 
#>     .default = case_when(hp < 254.5 ~ case_when(wt < 3.7039063 ~ 
#>         -0.29196888, .default = -0.34239012), .default = case_when(wt < 
#>         3.379375 ~ -0.21633774, .default = -0.25667438))), .default = case_when(hp < 
#>     224.5 | is.na(hp) ~ -0.4886111, .default = -0.27180085)))) + 
#>     case_when(cyl < 5 ~ case_when(wt < 2.2577705 | is.na(wt) ~ 
#>         case_when(wt < 1.8853853 ~ case_when(wt < 1.725376 ~ 
#>             0.36386615, .default = 0.48739767), .default = case_when(wt < 
#>             2.169276 | is.na(wt) ~ case_when(wt < 2.039326 ~ 
#>             0.25445274, .default = 0.20856972), .default = 0.4344556)), 
#>         .default = case_when(wt < 3.1699717 ~ case_when(hp < 
#>             96.5 ~ 0.09562649, .default = case_when(wt < 2.6247656 ~ 
#>             0.049743462, .default = 0.07050888)), .default = 0.15209839)), 
#>         .default = case_when(hp < 193 | is.na(hp) ~ case_when(wt < 
#>             3.3264766 ~ case_when(wt < 3.0449898 ~ case_when(hp < 
#>             143 | is.na(hp) ~ 0.009599304, .default = -0.013786927), 
#>             .default = 0.066913724), .default = case_when(wt < 
#>             3.8144138 | is.na(wt) ~ case_when(wt < 3.7551303 | 
#>             is.na(wt) ~ case_when(wt < 3.6250772 | is.na(wt) ~ 
#>             -0.11169243, .default = 0.0891806), .default = -0.36240026), 
#>             .default = case_when(wt < 3.9561841 ~ 0.05471512, 
#>                 .default = -0.11040047))), .default = case_when(hp < 
#>             222.5 ~ -0.34202775, .default = case_when(hp < 253.5 ~ 
#>             case_when(hp < 238 ~ -0.19026054, .default = case_when(wt < 
#>                 3.7086718 ~ -0.20437808, .default = -0.2396731)), 
#>             .default = case_when(wt < 3.3739061 ~ -0.15143657, 
#>                 .default = -0.17967196))))) + case_when(cyl < 
#>     5 ~ case_when(wt < 2.2577705 | is.na(wt) ~ case_when(wt < 
#>     1.8853853 ~ case_when(wt < 1.725376 ~ 0.2547061, .default = 0.3411788), 
#>     .default = case_when(wt < 2.169276 | is.na(wt) ~ case_when(wt < 
#>         2.039326 ~ 0.17811665, .default = 0.14599857), .default = 0.30411884)), 
#>     .default = case_when(wt < 3.1699717 ~ case_when(hp < 96.5 ~ 
#>         0.06693844, .default = case_when(wt < 2.6247656 ~ 0.034820367, 
#>         .default = 0.049356196)), .default = 0.10646908)), .default = case_when(cyl < 
#>     7 ~ case_when(wt < 3.3264766 | is.na(wt) ~ case_when(wt < 
#>     3.0449898 | is.na(wt) ~ case_when(hp < 143 | is.na(hp) ~ 
#>     0.0067193983, .default = -0.009651031), .default = 0.04683964), 
#>     .default = case_when(wt < 3.4495685 ~ -0.02263298, .default = -0.036750525)), 
#>     .default = case_when(wt < 4.662758 | is.na(wt) ~ case_when(hp < 
#>         163.5 ~ case_when(wt < 3.4723437 ~ -0.17039303, .default = -0.15526657), 
#>         .default = case_when(hp < 211.5 | is.na(hp) ~ case_when(wt < 
#>             3.7465625 ~ 0.0004972458, .default = -0.09755318), 
#>             .default = case_when(hp < 255.5 ~ -0.15541798, .default = -0.11588805))), 
#>         .default = case_when(hp < 224.5 | is.na(hp) ~ -0.23941945, 
#>             .default = -0.13318229)))) + case_when(cyl < 5 ~ 
#>     case_when(wt < 2.2577705 | is.na(wt) ~ case_when(wt < 1.8853853 ~ 
#>         case_when(wt < 1.725376 ~ 0.17829448, .default = 0.23882514), 
#>         .default = case_when(wt < 2.169276 | is.na(wt) ~ case_when(wt < 
#>             2.039326 ~ 0.1246819, .default = 0.102199174), .default = 0.2128831)), 
#>         .default = case_when(wt < 3.1699717 ~ case_when(hp < 
#>             96.5 ~ 0.046856917, .default = case_when(wt < 2.6247656 ~ 
#>             0.024374198, .default = 0.034549255)), .default = 0.07452862)), 
#>     .default = case_when(cyl < 7 ~ case_when(wt < 3.3264766 | 
#>         is.na(wt) ~ case_when(wt < 3.0449898 | is.na(wt) ~ case_when(hp < 
#>         143 | is.na(hp) ~ 0.0047035217, .default = -0.0067556766), 
#>         .default = 0.03278801), .default = case_when(wt < 3.4495685 ~ 
#>         -0.015843201, .default = -0.025725288)), .default = case_when(wt < 
#>         4.662758 | is.na(wt) ~ case_when(wt < 3.8114195 | is.na(wt) ~ 
#>         case_when(wt < 3.7512865 | is.na(wt) ~ case_when(wt < 
#>             3.651378 | is.na(wt) ~ -0.09137092, .default = 0.062277257), 
#>             .default = -0.22441429), .default = case_when(hp < 
#>         177.5 ~ 0.067566834, .default = case_when(wt < 3.955 ~ 
#>         -0.12114578, .default = -0.04801414))), .default = case_when(hp < 
#>         224.5 | is.na(hp) ~ -0.16759375, .default = -0.09322752)))) + 
#>     case_when(cyl < 5 ~ case_when(wt < 2.2577705 | is.na(wt) ~ 
#>         case_when(wt < 1.8853853 ~ case_when(wt < 1.725376 ~ 
#>             0.12480595, .default = 0.16717711), .default = case_when(wt < 
#>             2.169276 | is.na(wt) ~ case_when(wt < 2.039326 ~ 
#>             0.08727746, .default = 0.071539305), .default = 0.14901821)), 
#>         .default = case_when(wt < 3.1699717 ~ case_when(hp < 
#>             96.5 ~ 0.032799568, .default = case_when(wt < 2.6247656 ~ 
#>             0.017061997, .default = 0.02418434)), .default = 0.0521703)), 
#>         .default = case_when(cyl < 7 ~ case_when(wt < 3.3264766 | 
#>             is.na(wt) ~ case_when(wt < 3.0449898 | is.na(wt) ~ 
#>             case_when(hp < 143 | is.na(hp) ~ 0.0032924651, .default = -0.0047289277), 
#>             .default = 0.022951812), .default = case_when(wt < 
#>             3.4495685 ~ -0.01109047, .default = -0.018007964)), 
#>             .default = case_when(wt < 4.662758 | is.na(wt) ~ 
#>                 case_when(wt < 3.8114195 | is.na(wt) ~ case_when(wt < 
#>                   3.7512865 | is.na(wt) ~ case_when(wt < 3.651378 | 
#>                   is.na(wt) ~ -0.063959695, .default = 0.043594208), 
#>                   .default = -0.15709013), .default = case_when(hp < 
#>                   177.5 ~ 0.04729706, .default = case_when(wt < 
#>                   3.955 ~ -0.08480192, .default = -0.03361004))), 
#>                 .default = case_when(hp < 224.5 | is.na(hp) ~ 
#>                   -0.11731556, .default = -0.0652593)))))

From there, the Tidy Eval formula can be used anywhere it can be operated. tidypredict provides these paths:

  • Use directly inside dplyr, mutate(mtcars, !! tidypredict_fit(model))
  • Use tidypredict_sql(model) to retrieve the SQL statement
tidypredict_sql(model, dbplyr::simulate_dbi())
#> <SQL> 20.090625 + ((((((((CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 3.0928125 ELSE 4.1428123 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 2.1628125 ELSE 1.7728126 END)
#> ELSE 3.6928124
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.81281245 ELSE 0.4228125 END)
#> ELSE 1.2928125
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE WHEN ("cyl" < 5.0) THEN 0.39281252 ELSE 0.3128125 END)
#> ELSE -0.1171875
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.4771875 ELSE -0.5971875 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("hp" < 164.0) THEN (CASE WHEN ("wt" < 3.4846094) THEN -1.4671875 ELSE -1.3771875 END)
#> ELSE CASE WHEN ("hp" < 177.5) THEN -0.3421875 ELSE -1.1371875 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -1.7371875 ELSE -2.0371876 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -1.2871876 ELSE -1.5271875 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -2.9071875 ELSE -1.6171875 END
#> END
#> END
#> END + CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 2.1649687 ELSE 2.8999689 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 1.513969 ELSE 1.2409687 END)
#> ELSE 2.5849686
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.568969 ELSE 0.29596883 END)
#> ELSE 0.9049686
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE WHEN ("wt" < 3.0383594 OR ("wt" IS NULL)) THEN 0.210969 ELSE 0.298969 END)
#> ELSE -0.08203148
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.3340313 ELSE -0.41803104 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("hp" < 164.0) THEN (CASE WHEN ("wt" < 3.4846094) THEN -1.0270313 ELSE -0.9640314 END)
#> ELSE CASE WHEN ("hp" < 177.5) THEN -0.23953135 ELSE -0.79603136 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -1.2160312 ELSE -1.4260314 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -0.9010315 ELSE -1.0690315 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -2.035031 ELSE -1.1320314 END
#> END
#> END
#> END) + CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 1.5154783 ELSE 2.0299783 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 1.0597781 ELSE 0.8686781 END)
#> ELSE 1.8094782
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.39827806 ELSE 0.20717812 END)
#> ELSE 0.6334781
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE WHEN ("cyl" < 5.0) THEN 0.21167804 ELSE 0.1468781 END)
#> ELSE -0.0574221
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.23382169 ELSE -0.29262152 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("hp" < 164.0) THEN (CASE WHEN ("wt" < 3.4846094) THEN -0.7189221 ELSE -0.67482203 END)
#> ELSE CASE WHEN ("hp" < 177.5) THEN -0.1676722 ELSE -0.5572218 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -0.8512216 ELSE -0.9982221 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -0.63072205 ELSE -0.7483223 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -1.4245218 ELSE -0.7924223 END
#> END
#> END
#> END) + CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 1.0608349 ELSE 1.420985 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 0.7418446 ELSE 0.60807496 END)
#> ELSE 1.2666345
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.2787949 ELSE 0.14502469 END)
#> ELSE 0.44343463
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.0383594 OR ("wt" IS NULL)) THEN 0.09713482
#> ELSE 0.16521503
#> END)
#> ELSE -0.040195312
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.16367513 ELSE -0.20483504 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("hp" < 164.0) THEN (CASE WHEN ("wt" < 3.4846094) THEN -0.5032456 ELSE -0.47237548 END)
#> ELSE CASE WHEN ("hp" < 177.5) THEN -0.11737026 ELSE -0.39005503 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -0.5958553 ELSE -0.69875544 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -0.4415054 ELSE -0.5238258 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.9971653 ELSE -0.55469537 END
#> END
#> END
#> END) + CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 0.74258435 ELSE 0.9946897 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 0.51929134 ELSE 0.42565268 END)
#> ELSE 0.8866443
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.19515634 ELSE 0.1015171 END)
#> ELSE 0.3104045
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE WHEN ("cyl" < 5.0) THEN 0.11903412 ELSE 0.06686634 END)
#> ELSE -0.028136672
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.11457253 ELSE -0.1433843 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.8098438 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.7571313 OR ("wt" IS NULL)) THEN -0.20328303
#> ELSE -0.6030386
#> END)
#> ELSE CASE WHEN ("wt" < 3.9561818) THEN -0.007159081 ELSE -0.24303864 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -0.41709858 ELSE -0.48912886 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -0.30905378 ELSE -0.36667785 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.69801563 ELSE -0.3882868 END
#> END
#> END
#> END) + CASE
#> WHEN ("wt" < 2.2596803) THEN (CASE
#> WHEN ("wt" < 1.8848817) THEN (CASE WHEN ("wt" < 1.7250888) THEN 0.51980907 ELSE 0.69628274 END)
#> ELSE CASE
#> WHEN ("wt" < 2.1698422) THEN (CASE WHEN ("wt" < 2.0377436) THEN 0.36350405 ELSE 0.29795665 END)
#> ELSE 0.620651
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.326375 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 102.5) THEN (CASE
#> WHEN ("wt" < 3.1730468 OR ("wt" IS NULL)) THEN (CASE WHEN ("hp" < 96.5) THEN 0.1366095 ELSE 0.07106209 END)
#> ELSE 0.21728335
#> END)
#> ELSE CASE
#> WHEN ("hp" < 141.5 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.0383594 OR ("wt" IS NULL)) THEN 0.04271759
#> ELSE 0.0955909
#> END)
#> ELSE -0.01969551
#> END
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495606) THEN -0.08020077 ELSE -0.100368805 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.660125 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 211.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("hp" < 164.0) THEN (CASE WHEN ("wt" < 3.4846094) THEN -0.2912867 ELSE -0.26967773 END)
#> ELSE CASE WHEN ("wt" < 3.7525) THEN -0.004113865 ELSE -0.19908859 END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 254.5) THEN (CASE WHEN ("wt" < 3.7039063) THEN -0.29196888 ELSE -0.34239012 END)
#> ELSE CASE WHEN ("wt" < 3.379375) THEN -0.21633774 ELSE -0.25667438 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.4886111 ELSE -0.27180085 END
#> END
#> END
#> END) + CASE
#> WHEN ("cyl" < 5.0) THEN (CASE
#> WHEN ("wt" < 2.2577705 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 1.8853853) THEN (CASE WHEN ("wt" < 1.725376) THEN 0.36386615 ELSE 0.48739767 END)
#> ELSE CASE
#> WHEN ("wt" < 2.169276 OR ("wt" IS NULL)) THEN (CASE WHEN ("wt" < 2.039326) THEN 0.25445274 ELSE 0.20856972 END)
#> ELSE 0.4344556
#> END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 3.1699717) THEN (CASE
#> WHEN ("hp" < 96.5) THEN 0.09562649
#> ELSE CASE WHEN ("wt" < 2.6247656) THEN 0.049743462 ELSE 0.07050888 END
#> END)
#> ELSE 0.15209839
#> END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 193.0 OR ("hp" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.3264766) THEN (CASE
#> WHEN ("wt" < 3.0449898) THEN (CASE
#> WHEN ("hp" < 143.0 OR ("hp" IS NULL)) THEN 0.009599304
#> ELSE -0.013786927
#> END)
#> ELSE 0.066913724
#> END)
#> ELSE CASE
#> WHEN ("wt" < 3.8144138 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.7551303 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.6250772 OR ("wt" IS NULL)) THEN -0.11169243
#> ELSE 0.0891806
#> END)
#> ELSE -0.36240026
#> END)
#> ELSE CASE WHEN ("wt" < 3.9561841) THEN 0.05471512 ELSE -0.11040047 END
#> END
#> END)
#> ELSE CASE
#> WHEN ("hp" < 222.5) THEN -0.34202775
#> ELSE CASE
#> WHEN ("hp" < 253.5) THEN (CASE
#> WHEN ("hp" < 238.0) THEN -0.19026054
#> ELSE CASE WHEN ("wt" < 3.7086718) THEN -0.20437808 ELSE -0.2396731 END
#> END)
#> ELSE CASE WHEN ("wt" < 3.3739061) THEN -0.15143657 ELSE -0.17967196 END
#> END
#> END
#> END
#> END) + CASE
#> WHEN ("cyl" < 5.0) THEN (CASE
#> WHEN ("wt" < 2.2577705 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 1.8853853) THEN (CASE WHEN ("wt" < 1.725376) THEN 0.2547061 ELSE 0.3411788 END)
#> ELSE CASE
#> WHEN ("wt" < 2.169276 OR ("wt" IS NULL)) THEN (CASE WHEN ("wt" < 2.039326) THEN 0.17811665 ELSE 0.14599857 END)
#> ELSE 0.30411884
#> END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 3.1699717) THEN (CASE
#> WHEN ("hp" < 96.5) THEN 0.06693844
#> ELSE CASE WHEN ("wt" < 2.6247656) THEN 0.034820367 ELSE 0.049356196 END
#> END)
#> ELSE 0.10646908
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.3264766 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.0449898 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 143.0 OR ("hp" IS NULL)) THEN 0.0067193983
#> ELSE -0.009651031
#> END)
#> ELSE 0.04683964
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495685) THEN -0.02263298 ELSE -0.036750525 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.662758 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 163.5) THEN (CASE WHEN ("wt" < 3.4723437) THEN -0.17039303 ELSE -0.15526657 END)
#> ELSE CASE
#> WHEN ("hp" < 211.5 OR ("hp" IS NULL)) THEN (CASE WHEN ("wt" < 3.7465625) THEN 0.0004972458 ELSE -0.09755318 END)
#> ELSE CASE WHEN ("hp" < 255.5) THEN -0.15541798 ELSE -0.11588805 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.23941945 ELSE -0.13318229 END
#> END
#> END
#> END) + CASE
#> WHEN ("cyl" < 5.0) THEN (CASE
#> WHEN ("wt" < 2.2577705 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 1.8853853) THEN (CASE WHEN ("wt" < 1.725376) THEN 0.17829448 ELSE 0.23882514 END)
#> ELSE CASE
#> WHEN ("wt" < 2.169276 OR ("wt" IS NULL)) THEN (CASE WHEN ("wt" < 2.039326) THEN 0.1246819 ELSE 0.102199174 END)
#> ELSE 0.2128831
#> END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 3.1699717) THEN (CASE
#> WHEN ("hp" < 96.5) THEN 0.046856917
#> ELSE CASE WHEN ("wt" < 2.6247656) THEN 0.024374198 ELSE 0.034549255 END
#> END)
#> ELSE 0.07452862
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.3264766 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.0449898 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 143.0 OR ("hp" IS NULL)) THEN 0.0047035217
#> ELSE -0.0067556766
#> END)
#> ELSE 0.03278801
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495685) THEN -0.015843201 ELSE -0.025725288 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.662758 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.8114195 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.7512865 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.651378 OR ("wt" IS NULL)) THEN -0.09137092
#> ELSE 0.062277257
#> END)
#> ELSE -0.22441429
#> END)
#> ELSE CASE
#> WHEN ("hp" < 177.5) THEN 0.067566834
#> ELSE CASE WHEN ("wt" < 3.955) THEN -0.12114578 ELSE -0.04801414 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.16759375 ELSE -0.09322752 END
#> END
#> END
#> END) + CASE
#> WHEN ("cyl" < 5.0) THEN (CASE
#> WHEN ("wt" < 2.2577705 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 1.8853853) THEN (CASE WHEN ("wt" < 1.725376) THEN 0.12480595 ELSE 0.16717711 END)
#> ELSE CASE
#> WHEN ("wt" < 2.169276 OR ("wt" IS NULL)) THEN (CASE WHEN ("wt" < 2.039326) THEN 0.08727746 ELSE 0.071539305 END)
#> ELSE 0.14901821
#> END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 3.1699717) THEN (CASE
#> WHEN ("hp" < 96.5) THEN 0.032799568
#> ELSE CASE WHEN ("wt" < 2.6247656) THEN 0.017061997 ELSE 0.02418434 END
#> END)
#> ELSE 0.0521703
#> END
#> END)
#> ELSE CASE
#> WHEN ("cyl" < 7.0) THEN (CASE
#> WHEN ("wt" < 3.3264766 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.0449898 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("hp" < 143.0 OR ("hp" IS NULL)) THEN 0.0032924651
#> ELSE -0.0047289277
#> END)
#> ELSE 0.022951812
#> END)
#> ELSE CASE WHEN ("wt" < 3.4495685) THEN -0.01109047 ELSE -0.018007964 END
#> END)
#> ELSE CASE
#> WHEN ("wt" < 4.662758 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.8114195 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.7512865 OR ("wt" IS NULL)) THEN (CASE
#> WHEN ("wt" < 3.651378 OR ("wt" IS NULL)) THEN -0.063959695
#> ELSE 0.043594208
#> END)
#> ELSE -0.15709013
#> END)
#> ELSE CASE
#> WHEN ("hp" < 177.5) THEN 0.04729706
#> ELSE CASE WHEN ("wt" < 3.955) THEN -0.08480192 ELSE -0.03361004 END
#> END
#> END)
#> ELSE CASE WHEN ("hp" < 224.5 OR ("hp" IS NULL)) THEN -0.11731556 ELSE -0.0652593 END
#> END
#> END
#> END

Categorical predictors

H2O handles categorical predictors natively. The generated formula uses %in% for categorical splits.

mtcars2 <- mtcars
mtcars2$cyl <- factor(mtcars2$cyl)
mtcars2$gear <- factor(mtcars2$gear)

model_cat <- boost_tree(mode = "regression", trees = 10) |>
  set_engine("h2o_gbm") |>
  fit(mpg ~ cyl + gear + wt, data = mtcars2)

tidypredict_fit(model_cat)
#> 20.090625 + (case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ 
#>     case_when(wt < 1.7250888 ~ 3.0928125, .default = 4.1428123), 
#>     .default = case_when(wt < 2.1698422 ~ case_when(gear %in% 
#>         c("3", "5") ~ 1.7728126, .default = 2.1628125), .default = 3.6928124)), 
#>     .default = case_when(cyl %in% "8" | is.na(cyl) ~ case_when(wt < 
#>         4.6576414 | is.na(wt) ~ case_when(wt < 3.8440876 | is.na(wt) ~ 
#>         case_when(wt < 3.8072233 | is.na(wt) ~ case_when(wt < 
#>             3.478655 ~ -1.0571876, .default = -1.3891875), .default = -2.0371876), 
#>         .default = case_when(wt < 3.957044 ~ -0.2671875, .default = -1.1071875)), 
#>         .default = case_when(wt < 5.2952757 ~ -2.9071875, .default = case_when(wt < 
#>             5.383774 ~ -1.6171875, .default = -2.9071875))), 
#>         .default = case_when(wt < 3.3288743 | is.na(wt) ~ case_when(cyl %in% 
#>             "6" ~ case_when(gear %in% "5" ~ -0.1171875, .default = case_when(gear %in% 
#>             "4" | is.na(gear) ~ 0.27281252, .default = 0.39281252)), 
#>             .default = case_when(wt < 3.1712377 | is.na(wt) ~ 
#>                 case_when(wt < 2.3998036 ~ 0.81281245, .default = 0.54281247), 
#>                 .default = 1.2928125)), .default = case_when(gear %in% 
#>             c("3", "5") ~ -0.5971875, .default = -0.4771875)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 2.1649687, .default = 2.8999689), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 1.2409687, 
#>         .default = 1.513969), .default = 2.5849686)), .default = case_when(cyl %in% 
#>         "8" | is.na(cyl) ~ case_when(wt < 4.6576414 | is.na(wt) ~ 
#>         case_when(wt < 3.8440876 | is.na(wt) ~ case_when(wt < 
#>             3.8072233 | is.na(wt) ~ case_when(wt < 3.478655 ~ 
#>             -0.7400313, .default = -0.97243106), .default = -1.4260314), 
#>             .default = case_when(wt < 3.957044 ~ -0.18703103, 
#>                 .default = -0.775031)), .default = case_when(wt < 
#>         5.2952757 ~ -2.035031, .default = case_when(wt < 5.383774 ~ 
#>         -1.1320314, .default = -2.035031))), .default = case_when(wt < 
#>         3.3288743 | is.na(wt) ~ case_when(cyl %in% "6" ~ case_when(gear %in% 
#>         "5" ~ -0.08203148, .default = case_when(gear %in% "4" | 
#>         is.na(gear) ~ 0.1909687, .default = 0.274969)), .default = case_when(wt < 
#>         2.96631 | is.na(wt) ~ case_when(wt < 2.4007888 ~ 0.568969, 
#>         .default = 0.24496856), .default = case_when(wt < 3.169029 ~ 
#>         0.64996856, .default = 0.9049686))), .default = case_when(gear %in% 
#>         c("3", "5") ~ -0.41803104, .default = -0.3340313)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 1.5154783, .default = 2.0299783), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.8686781, 
#>         .default = 1.0597781), .default = 1.8094782)), .default = case_when(cyl %in% 
#>         "8" | is.na(cyl) ~ case_when(wt < 4.6576414 | is.na(wt) ~ 
#>         case_when(wt < 3.8440876 | is.na(wt) ~ case_when(wt < 
#>             3.8072233 | is.na(wt) ~ case_when(wt < 3.657874 | 
#>             is.na(wt) ~ -0.6783617, .default = -0.44370174), 
#>             .default = -0.9982221), .default = case_when(wt < 
#>             3.957044 ~ -0.13092178, .default = -0.54252195)), 
#>         .default = case_when(wt < 5.2952757 ~ -1.4245218, .default = case_when(wt < 
#>             5.383774 ~ -0.7924223, .default = -1.4245218))), 
#>         .default = case_when(wt < 3.3288743 | is.na(wt) ~ case_when(cyl %in% 
#>             "6" ~ case_when(gear %in% "5" ~ -0.0574221, .default = case_when(gear %in% 
#>             "4" | is.na(gear) ~ 0.13367787, .default = 0.19247828)), 
#>             .default = case_when(wt < 2.96631 | is.na(wt) ~ case_when(wt < 
#>                 2.4007888 ~ 0.39827806, .default = 0.17147803), 
#>                 .default = case_when(wt < 3.169029 ~ 0.4549778, 
#>                   .default = 0.6334781))), .default = case_when(gear %in% 
#>             c("3", "5") ~ -0.29262152, .default = -0.23382169)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 1.0608349, .default = 1.420985), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.60807496, 
#>         .default = 0.7418446), .default = 1.2666345)), .default = case_when(cyl %in% 
#>         "8" | is.na(cyl) ~ case_when(wt < 4.6576414 | is.na(wt) ~ 
#>         case_when(wt < 3.4373105 ~ case_when(gear %in% c("3", 
#>         "4") ~ -0.72451305, .default = -0.5445131), .default = case_when(wt < 
#>             3.4817965 ~ 0.32548693, .default = case_when(wt < 
#>             3.6472287 ~ -0.63519317, .default = -0.35826975))), 
#>         .default = case_when(wt < 5.2952757 ~ -0.9971653, .default = case_when(wt < 
#>             5.383774 ~ -0.55469537, .default = -0.9971653))), 
#>         .default = case_when(wt < 3.3288743 | is.na(wt) ~ case_when(cyl %in% 
#>             "6" ~ case_when(gear %in% "5" ~ -0.040195312, .default = case_when(gear %in% 
#>             "4" | is.na(gear) ~ 0.09357433, .default = 0.13473484)), 
#>             .default = case_when(wt < 2.96631 | is.na(wt) ~ case_when(wt < 
#>                 2.4007888 ~ 0.2787949, .default = 0.12003456), 
#>                 .default = case_when(wt < 3.169029 ~ 0.31848472, 
#>                   .default = 0.44343463))), .default = case_when(gear %in% 
#>             c("3", "5") ~ -0.20483504, .default = -0.16367513)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.74258435, .default = 0.9946897), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.42565268, 
#>         .default = 0.51929134), .default = 0.8866443)), .default = case_when(cyl %in% 
#>         "8" | is.na(cyl) ~ case_when(wt < 4.6576414 | is.na(wt) ~ 
#>         case_when(wt < 3.8440876 | is.na(wt) ~ case_when(wt < 
#>             3.7545602 | is.na(wt) ~ case_when(wt < 3.6449552 | 
#>             is.na(wt) ~ -0.33239716, .default = 0.11188969), 
#>             .default = case_when(wt < 3.8092952 ~ -0.5181103, 
#>                 .default = -0.5912745)), .default = case_when(wt < 
#>             3.957044 ~ 0.015836105, .default = -0.27228403)), 
#>         .default = case_when(wt < 5.2952757 ~ -0.69801563, .default = case_when(wt < 
#>             5.383774 ~ -0.3882868, .default = -0.69801563))), 
#>         .default = case_when(wt < 3.3288743 | is.na(wt) ~ case_when(cyl %in% 
#>             "6" ~ case_when(gear %in% "5" ~ -0.028136672, .default = case_when(gear %in% 
#>             "4" | is.na(gear) ~ 0.06550197, .default = 0.09431431)), 
#>             .default = case_when(wt < 2.96631 | is.na(wt) ~ case_when(wt < 
#>                 2.4007888 ~ 0.19515634, .default = 0.08402401), 
#>                 .default = case_when(wt < 3.169029 ~ 0.22293915, 
#>                   .default = 0.3104045))), .default = case_when(gear %in% 
#>             c("3", "5") ~ -0.1433843, .default = -0.11457253)))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.51980907, .default = 0.69628274), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.29795665, 
#>         .default = 0.36350405), .default = 0.620651)), .default = case_when(wt < 
#>         3.4895623 | is.na(wt) ~ case_when(cyl %in% c("6", "8"
#>     ) | is.na(cyl) ~ case_when(gear %in% "5" ~ case_when(cyl %in% 
#>         "8" ~ -0.28143975, .default = -0.01969551), .default = case_when(wt < 
#>         3.3250926 ~ case_when(gear %in% "4" | is.na(gear) ~ 0.045851327, 
#>         .default = 0.06601994), .default = case_when(wt < 3.4389207 ~ 
#>         -0.40743965, .default = 0.01669742))), .default = case_when(wt < 
#>         2.964173 | is.na(wt) ~ case_when(wt < 2.395489 ~ 0.1366095, 
#>         .default = case_when(gear %in% c("4", "5") ~ 0.043816682, 
#>             .default = 0.07381668)), .default = case_when(wt < 
#>         3.1688287 ~ 0.1560576, .default = 0.21728335))), .default = case_when(wt < 
#>         4.657026 ~ case_when(wt < 3.6488037 ~ case_when(wt < 
#>         3.545157 ~ -0.17491607, .default = case_when(gear %in% 
#>         c("3", "4") ~ -0.5349161, .default = -0.32491606)), .default = case_when(wt < 
#>         3.7541027 ~ 0.07832302, .default = case_when(wt < 3.842949 ~ 
#>         -0.38828474, .default = -0.08975693))), .default = case_when(wt < 
#>         5.295172 ~ -0.4886111, .default = case_when(wt < 5.3837414 ~ 
#>         -0.27180085, .default = -0.4886111))))) + case_when(wt < 
#>     2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 1.7250888 ~ 
#>     0.36386615, .default = 0.48739767), .default = case_when(wt < 
#>     2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.20856972, 
#>     .default = 0.25445274), .default = 0.4344556)), .default = case_when(wt < 
#>     3.4493904 | is.na(wt) ~ case_when(cyl %in% c("6", "8") | 
#>     is.na(cyl) ~ case_when(gear %in% "5" ~ case_when(cyl %in% 
#>     "8" ~ -0.19700809, .default = -0.013786927), .default = case_when(wt < 
#>     3.3258634 ~ case_when(gear %in% "4" | is.na(gear) ~ 0.0320961, 
#>     .default = 0.04621422), .default = case_when(wt < 3.4364333 ~ 
#>     -0.2852076, .default = 0.050710417))), .default = case_when(wt < 
#>     2.968517 | is.na(wt) ~ case_when(wt < 2.395998 ~ 0.09562649, 
#>     .default = case_when(gear %in% c("4", "5") ~ 0.030671425, 
#>         .default = 0.05167179)), .default = case_when(wt < 3.169236 ~ 
#>     0.10924038, .default = 0.15209839))), .default = case_when(wt < 
#>     4.6603813 ~ case_when(wt < 3.8444972 ~ case_when(wt < 3.7543807 ~ 
#>     case_when(wt < 3.6485877 ~ -0.20742543, .default = 0.05482601), 
#>     .default = case_when(wt < 3.8092306 ~ -0.24619183, .default = -0.29740682)), 
#>     .default = case_when(wt < 3.9572487 ~ 0.038011894, .default = -0.16367215)), 
#>     .default = case_when(wt < 5.295736 ~ -0.34202775, .default = case_when(wt < 
#>         5.3839173 ~ -0.19026054, .default = -0.34202775))))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.2547061, .default = 0.3411788), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.14599857, 
#>         .default = 0.17811665), .default = 0.30411884)), .default = case_when(wt < 
#>         3.545185 | is.na(wt) ~ case_when(cyl %in% c("6", "8") | 
#>         is.na(cyl) ~ case_when(gear %in% c("4", "5") | is.na(gear) ~ 
#>         case_when(wt < 3.0187383 ~ case_when(gear %in% "5" ~ 
#>             -0.009651031, .default = 0.022467041), .default = case_when(cyl %in% 
#>             "8" ~ -0.13790566, .default = -0.10042306)), .default = case_when(wt < 
#>         3.4494674 | is.na(wt) ~ case_when(cyl %in% "6" ~ 0.032349702, 
#>         .default = 0.053846233), .default = case_when(cyl %in% 
#>         "8" ~ -0.060213663, .default = -0.043150064))), .default = case_when(wt < 
#>         2.9660938 | is.na(wt) ~ case_when(wt < 2.395714 ~ 0.06693844, 
#>         .default = case_when(gear %in% c("4", "5") ~ 0.021469802, 
#>             .default = 0.036170196)), .default = case_when(wt < 
#>         3.1690087 ~ 0.07646851, .default = 0.10646908))), .default = case_when(wt < 
#>         3.6516023 ~ case_when(gear %in% c("3", "4") ~ -0.31221378, 
#>         .default = -0.16521378), .default = case_when(wt < 3.7554536 ~ 
#>         0.03837799, .default = case_when(wt < 4.66794 ~ case_when(wt < 
#>         3.8216221 ~ -0.17233424, .default = -0.09871565), .default = case_when(wt < 
#>         5.294052 ~ -0.23941945, .default = -0.18630086)))))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.17829448, .default = 0.23882514), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.102199174, 
#>         .default = 0.1246819), .default = 0.2128831)), .default = case_when(wt < 
#>         3.545185 | is.na(wt) ~ case_when(cyl %in% c("6", "8") | 
#>         is.na(cyl) ~ case_when(wt < 3.4398956 | is.na(wt) ~ case_when(cyl %in% 
#>         "8" ~ case_when(gear %in% c("3", "4") ~ -0.21579918, 
#>         .default = -0.09653412), .default = case_when(gear %in% 
#>         "5" ~ -0.0067556766, .default = 0.018032875)), .default = case_when(cyl %in% 
#>         "6" | is.na(cyl) ~ case_when(gear %in% c("4", "5") | 
#>         is.na(gear) ~ -0.07029591, .default = -0.030205078), 
#>         .default = case_when(wt < 3.4799478 ~ 0.2911838, .default = -0.042149447))), 
#>         .default = case_when(wt < 2.9660938 | is.na(wt) ~ case_when(wt < 
#>             2.395714 ~ 0.046856917, .default = case_when(gear %in% 
#>             c("4", "5") ~ 0.015029067, .default = 0.02531891)), 
#>             .default = case_when(wt < 3.1690087 ~ 0.05352768, 
#>                 .default = 0.07452862))), .default = case_when(wt < 
#>         3.6516023 ~ case_when(gear %in% c("3", "4") ~ -0.2185496, 
#>         .default = -0.1156497), .default = case_when(wt < 3.7554536 ~ 
#>         0.02686466, .default = case_when(wt < 5.371858 ~ case_when(wt < 
#>         4.6505475 ~ -0.08198429, .default = -0.122442834), .default = -0.18352908))))) + 
#>     case_when(wt < 2.2596803 ~ case_when(wt < 1.8848817 ~ case_when(wt < 
#>         1.7250888 ~ 0.12480595, .default = 0.16717711), .default = case_when(wt < 
#>         2.1698422 ~ case_when(gear %in% c("3", "5") ~ 0.071539305, 
#>         .default = 0.08727746), .default = 0.14901821)), .default = case_when(wt < 
#>         3.545185 | is.na(wt) ~ case_when(cyl %in% c("6", "8") | 
#>         is.na(cyl) ~ case_when(wt < 3.4398956 | is.na(wt) ~ case_when(cyl %in% 
#>         "8" ~ case_when(gear %in% c("3", "4") ~ -0.15105939, 
#>         .default = -0.067573704), .default = case_when(gear %in% 
#>         "5" ~ -0.0047289277, .default = 0.012623252)), .default = case_when(cyl %in% 
#>         "6" | is.na(cyl) ~ case_when(gear %in% c("4", "5") | 
#>         is.na(gear) ~ -0.049207307, .default = -0.021143645), 
#>         .default = case_when(wt < 3.4799478 ~ 0.20382877, .default = -0.029504586))), 
#>         .default = case_when(wt < 2.9660938 | is.na(wt) ~ case_when(wt < 
#>             2.395714 ~ 0.032799568, .default = case_when(gear %in% 
#>             c("4", "5") ~ 0.010520095, .default = 0.017723465)), 
#>             .default = case_when(wt < 3.1690087 ~ 0.037469327, 
#>                 .default = 0.0521703))), .default = case_when(wt < 
#>         3.6516023 ~ case_when(gear %in% c("3", "4") ~ -0.15298468, 
#>         .default = -0.08095493), .default = case_when(wt < 3.7554536 ~ 
#>         0.01880516, .default = case_when(wt < 5.371858 ~ case_when(wt < 
#>         4.6505475 ~ -0.057389073, .default = -0.08570987), .default = -0.1284704))))))

Classification

For binary classification, tidypredict_fit() returns the probability of the second (positive) outcome level via the logistic link.

mtcars3 <- mtcars
mtcars3$vs <- factor(mtcars3$vs)

model_bin <- boost_tree(mode = "classification", trees = 10) |>
  set_engine("h2o_gbm") |>
  fit(vs ~ wt + cyl + hp, data = mtcars3)

tidypredict_fit(model_bin)
#> 1/(1 + exp(-(-0.251314428280906 + (case_when(hp < 136.5 | is.na(hp) ~ 
#>     case_when(wt < 3.013999 | is.na(wt) ~ case_when(cyl < 5 | 
#>         is.na(cyl) ~ case_when(wt < 2.1673985 | is.na(wt) ~ case_when(wt < 
#>         2.0395863 | is.na(wt) ~ 0.6857143, .default = -0.53333336), 
#>         .default = 0.6857143), .default = -0.53333336), .default = 0.6857143), 
#>     .default = -0.53333336) + case_when(hp < 136.5 | is.na(hp) ~ 
#>     case_when(wt < 3.013999 | is.na(wt) ~ case_when(cyl < 5 | 
#>         is.na(cyl) ~ case_when(hp < 78.5 ~ 0.49429598, .default = case_when(hp < 
#>         92 ~ -0.43688414, .default = 0.49429598)), .default = -0.43688414), 
#>         .default = 0.49429598), .default = -0.43688414) + case_when(hp < 
#>     136.5 | is.na(hp) ~ case_when(wt < 3.013999 | is.na(wt) ~ 
#>     case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 2.1673985 | 
#>         is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 0.4185206, 
#>         .default = -0.3884335), .default = 0.4185206), .default = -0.3884335), 
#>     .default = 0.4185206), .default = -0.3884335) + case_when(hp < 
#>     136.5 | is.na(hp) ~ case_when(wt < 3.013999 | is.na(wt) ~ 
#>     case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 2.1673985 | 
#>         is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 0.37798885, 
#>         .default = -0.35996836), .default = 0.37798885), .default = -0.35996836), 
#>     .default = 0.37798885), .default = -0.35996836) + case_when(hp < 
#>     136.5 | is.na(hp) ~ case_when(wt < 3.013999 | is.na(wt) ~ 
#>     case_when(cyl < 5 | is.na(cyl) ~ case_when(hp < 78.5 ~ 0.35344094, 
#>         .default = case_when(hp < 92 ~ -0.34183982, .default = 0.35344094)), 
#>         .default = -0.34183982), .default = 0.35344094), .default = -0.34183982) + 
#>     case_when(hp < 136.5 | is.na(hp) ~ case_when(wt < 3.013999 | 
#>         is.na(wt) ~ case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 
#>         2.1673985 | is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 
#>         0.33752984, .default = -0.3297256), .default = 0.33752984), 
#>         .default = -0.3297256), .default = 0.33752984), .default = -0.3297256) + 
#>     case_when(hp < 136.5 | is.na(hp) ~ case_when(wt < 3.013999 | 
#>         is.na(wt) ~ case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 
#>         2.1673985 | is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 
#>         0.32677868, .default = -0.32137632), .default = 0.32677868), 
#>         .default = -0.32137632), .default = 0.32677868), .default = -0.32137632) + 
#>     case_when(hp < 136.5 | is.na(hp) ~ case_when(wt < 3.013999 | 
#>         is.na(wt) ~ case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 
#>         2.1673985 | is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 
#>         0.31931394, .default = -0.31550103), .default = 0.31931394), 
#>         .default = -0.31550103), .default = 0.31931394), .default = -0.31550103) + 
#>     case_when(hp < 136.5 | is.na(hp) ~ case_when(wt < 3.013999 | 
#>         is.na(wt) ~ case_when(cyl < 5 | is.na(cyl) ~ case_when(wt < 
#>         2.1673985 | is.na(wt) ~ case_when(wt < 2.0395863 | is.na(wt) ~ 
#>         0.31403443, .default = -0.31130683), .default = 0.31403443), 
#>         .default = -0.31130683), .default = 0.31403443), .default = -0.31130683) + 
#>     case_when(hp < 136.5 | is.na(hp) ~ case_when(wt < 3.013999 | 
#>         is.na(wt) ~ case_when(cyl < 5 | is.na(cyl) ~ case_when(hp < 
#>         78.5 ~ 0.31025207, .default = case_when(hp < 92 ~ -0.30828214, 
#>         .default = 0.31025207)), .default = -0.30828214), .default = 0.31025207), 
#>         .default = -0.30828214)))))

For multiclass classification, tidypredict_fit() returns a named list with one softmax probability formula per class.

model_multi <- boost_tree(mode = "classification", trees = 10) |>
  set_engine("h2o_gbm") |>
  fit(Species ~ ., data = iris)

names(tidypredict_fit(model_multi))
#> [1] "setosa"     "versicolor" "virginica"

Limitations

Only H2O’s GBM models are supported, not H2O’s XGBoost. The gaussian, bernoulli, and multinomial distributions are supported. Because predictions require a live H2O cluster, the parsed formula cannot be reused after the cluster is shut down.