xgboost/R-package/demo/predict_first_ntree.R
Philip Hyunsu Cho 5879acde9a
[CI] Improve R linter script (#5944)
* [CI] Move lint to a separate script

* [CI] Improved lintr launcher

* Add lintr as a separate action

* Add custom parsing logic to print out logs

* Fix lintr issues in demos

* Run R demos

* Fix CRAN checks

* Install XGBoost into R env before running lintr

* Install devtools (needed to run demos)
2020-07-27 00:55:35 -07:00

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892 B
R

require(xgboost)
# load in the agaricus dataset
data(agaricus.train, package = 'xgboost')
data(agaricus.test, package = 'xgboost')
dtrain <- xgb.DMatrix(agaricus.train$data, label = agaricus.train$label)
dtest <- xgb.DMatrix(agaricus.test$data, label = agaricus.test$label)
param <- list(max_depth = 2, eta = 1, objective = 'binary:logistic')
watchlist <- list(eval = dtest, train = dtrain)
nrounds <- 2
# training the model for two rounds
bst <- xgb.train(param, dtrain, nrounds, nthread = 2, watchlist)
cat('start testing prediction from first n trees\n')
labels <- getinfo(dtest, 'label')
### predict using first 1 tree
ypred1 <- predict(bst, dtest, ntreelimit = 1)
# by default, we predict using all the trees
ypred2 <- predict(bst, dtest)
cat('error of ypred1=', mean(as.numeric(ypred1 > 0.5) != labels), '\n')
cat('error of ypred2=', mean(as.numeric(ypred2 > 0.5) != labels), '\n')