请教下K-opls的问题，我按照文献上面的代码运行数据，但是就是做不了，求助大家，谢谢
[s:15]>library(kopls)
> dx=read.table("1.txt")
> Xtr=dx
> svd.res <- svd(Xtr, nu = 2, nv = 2)
> plot(svd.res$u[, 1], svd.res$u[, 2], col = col.vec, pch = pch.vec,xlab = "PC1", ylab = "PC2", main = "PCA of original data set")
Error in plot.xy(xy, type, ...) : object 'pch.vec' not found
> plot(svd.res$u[, 1], svd.res$u[, 2],xlab = "PC1", ylab = "PC2", main = "PCA of original data set")
> sigma<-25
> Ktr<-koplsKernel(Xtr,NULL,'g',sigma)
Error in if (fast.calc) { : argument is of length zero
In addition: Warning message:
In is.na(X2[1]) : is.na() applied to non-(list or vector) of type 'NULL'
这一步不知道出现问题在哪，不知怎么解决？非常感谢
