Hi, I'm running the function gbm.step() from dismo package on the following dataset:
'data.frame': 427205 obs. of 17 variables:
$ Nsamples : num 92.2 92.2 92.2 92.2 92.2 92.2 92.2 92.2 92.2 92.2 ...
$ R : num 44.9 44.9 44.9 44.9 44.9 ...
$ P50 : num 0.845 0.847 0.846 0.846 0.846 ...
$ unc_reg : Factor w/ 465 levels "ur1","ur10","ur100",..: 1 1 1 1 1 1 1 1 1 1 ...
$ HasRes : num 1 1 1 1 1 1 1 1 1 1 ...
$ use : num 9.54 9.54 9.54 9.54 9.54 ...
$ acc : num 1.49 1.49 1.49 1.49 1.49 ...
$ tmp : num 2.45 2.45 2.45 2.45 2.45 ...
$ irg : num 1.76 1.76 1.76 1.76 1.76 ...
$ PgExt : num 3.41 3.41 3.41 3.41 3.41 ...
$ PgInt : num 3.74 3.74 3.74 3.74 3.74 ...
$ ChExt : num 4.22 4.22 4.22 4.22 4.22 ...
$ ChInt : num 5.57 5.57 5.57 5.57 5.57 ...
$ Ca : num 3.68 3.68 3.68 3.68 3.68 ...
$ veg : num 0 0 0 0 0 0 0 0 0 0 ...
$ Region.num: num 3 3 3 3 3 3 3 3 3 3 ...
$ Region : num 3 3 3 3 3 3 3 3 3 3 ...
- attr(*, "na.action")= 'omit' Named int [1:33915] 85075 85078 85084 85088 85090 85091 85092 85095 85099 85101 ...
..- attr(*, "names")= chr [1:33915] "13379" "477" "101000" "14103" ...
using the following command
myBRT2<- gbm.step(data = DFbrt_df2,
gbm.x = ColIndexCov,
gbm.y = ColIndexResp,
tree.complexity = 3,
learning.rate = 0.000005,
n.trees = 50,
family = "bernoulli",
n.folds = 4,
fold.vector = DFbrt_df2$Region.num,
step.size = 5,
verbose = F,
silent = T )
but it returns an empty vector. If I reduce the amount of data and I run the function several times, a small amount of them returns the result, otherwise always an empty vector. There is anyone who knows why this happens?
Thanks for your help!