我正在使用 glmnet 进行预测，并收到一个非常晦涩的错误信息。
在使用 glmnet 时，我以前从未遇到过这种情况，谷歌搜索也没有有效果。当取消注释最后一行时出现了该错误。
library(ISLR)
library(glmnet)
Hitters=na.omit(Hitters)
Hitters$Salary = log(Hitters$Salary)
Hitters.train = Hitters[1:200,]
Hitters.test = Hitters[201:dim(Hitters)[1],]
x=model.matrix(Salary~.,Hitters)[,-1]
cv.out=cv.glmnet(x, Hitters$Salary, alpha=0)
bestlam=cv.out$lambda.min
ridge.mod=glmnet(x, Hitters$Salary, alpha=0,lambda=bestlam)
newx = data.matrix(Hitters.test)
#ridge.pred=predict(ridge.mod,s=bestlam,newx=newx)
错误输出：
Loading required package: Matrix
Loading required package: methods
Loaded glmnet 1.9-5
Error in as.matrix(cbind2(1, newx) %*% nbeta) :
error in evaluating the argument 'x' in selecting a method for function 'as.matrix': Error in t(.Call(Csparse_dense_crossprod, y, t(x))) :
error in evaluating the argument 'x' in selecting a method for function 't': Error: Cholmod error 'X and/or Y have wrong dimensions' at file ../MatrixOps/cholmod_sdmult.c, line 90
Calls: %*% -> %*% -> t
Calls: predict ... predict.elnet -> NextMethod -> predict.glmnet -> as.matrix
Execution halted
请注意，将newx = data.matrix(Hitters.test)更改为newx = model.matrix(Salary~.,Hitters.test)并没有帮助。
按要求，在运行之前，这里是sessionInfo（）的输出结果。
> sessionInfo()
R version 3.0.2 (2013-09-25)
Platform: x86_64-unknown-linux-gnu (64-bit)
locale:
[1] C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
运行后的输出如下：
> sessionInfo()
R version 3.0.2 (2013-09-25)
Platform: x86_64-unknown-linux-gnu (64-bit)
locale:
[1] C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] glmnet_1.9-5 Matrix_1.1-0 ISLR_1.0
loaded via a namespace (and not attached):
[1] grid_3.0.2 lattice_0.20-23
sessionInfo()的结果。有一些小概率是由于最近对Matrix包的更新，或者Matrix和glmnet版本之间的不匹配引起的...？ - Ben Bolker