这是我的代码

w<-read.csv("e:/RF/huizong111.csv",header = T)
ind<-sample(2,nrow(w),replace = TRUE,prob = c(0.75,0.25))
traindata<-w[ind==1,]
testdata<-w[ind==2,]
train<-as.matrix(traindata)
test<-as.matrix(testdata[,-1])
y<-as.matrix(traindata$fl)
library(xgboost）
xgb <- xgboost(data = train, label = y, eta = 0.1,max_depth = 15, nround=25, subsample = 0.5,colsample_bytree = 0.5,seed = 1,eval_metric = "merror",objective = "multi:softprob",num_class = 12,nthread = 3)

[1]        train-merror:0.000000
[2]        train-merror:0.000000
[3]        train-merror:0.000000
[4]        train-merror:0.000000
[5]        train-merror:0.000000
[6]        train-merror:0.000000
[7]        train-merror:0.000000
[8]        train-merror:0.000000
[9]        train-merror:0.000000
[10]        train-merror:0.000000
[11]        train-merror:0.000000
[12]        train-merror:0.000000
[13]        train-merror:0.000000
[14]        train-merror:0.000000
[15]        train-merror:0.000000
[16]        train-merror:0.000000
[17]        train-merror:0.000000
...
结果都为0，不知道为什么