[英]Error with custom SVM model for tuning in caret
我試圖通過此鏈接創建自定義SVM,並通過一些交叉驗證運行它。 我這樣做的主要原因是在我的網格搜索中運行Sigma,Cost和Epsilon參數,而最接近的插入符號模型(svmRadial)只能做到其中兩個。
當我嘗試運行以下代碼時,在網格的每次迭代中到處都會出現以下錯誤:
Warning in eval(expr, envir, enclos) :
model fit failed for Fold1.: sigma=0.2, C=2, epsilon=0.1 Error in if (!isS4(modelFit) & !(method$label %in% c("Ensemble Partial Least Squares Regression", :
argument is of length zero
即使從逐字復制鏈接中的代碼時,我也會遇到類似的錯誤,並且不確定如何解決它。 我發現該鏈接遍歷了自定義模型的構建方式,並且看到了引用此錯誤的位置,但是仍然不確定問題出在哪里。 我的代碼如下:
#Generate Tuning Criteria across Parameters
C <- c(1,2)
sigma <- c(0.1,.2)
epsilon <- c(0.1,.2)
grid <- data.frame(C,sigma)
#Parameters
prm <- data.frame(parameter = c("C", "sigma","epsilon"),
class = rep("numeric", 3),
label = c("Cost", "Sigma", "Epsilon"))
#Tuning Grid
svmGrid <- function(x, y, len = NULL) {
expand.grid(sigma = sigma,
C = C,
epsilon = epsilon)
}
#Fit Element Function
svmFit <- function(x, y, wts, param, lev, last, weights, classProbs, ...) {
ksvm(x = as.matrix(x), y = y,
type = "eps-svr",
kernel = rbfdot,
kpar = list(sigma = param$sigma),
C = param$C,
epsilon = param$epsilon,
prob.model = classProbs,
...)
}
#Predict Element Function
svmPred <- function(modelFit, newdata, preProc = NULL, submodels = NULL)
predict(modelFit, newdata)
#Sort Element Function
svmSort <- function(x) x[order(x$C),]
#Model
newSVM <- list(type="Regression",
library="kernlab",
loop = NULL,
parameters = prm,
grid = svmGrid,
fit = svmFit,
predict = svmPred,
prob = NULL,
sort = svmSort,
levels = NULL)
#Train
tc<-trainControl("repeatedcv",number=2, repeats = 0,
verboseIter = T,savePredictions=T)
svmCV <- train(
Y~ 1
+ X1
+ X2
,data = data_nn,
method=newSVM,
trControl=tc
,preProc = c("center","scale"))
svmCV
在查看了提供的第二個鏈接之后,我決定嘗試在模型的參數中包含一個標簽,從而解決了該問題! 有趣的是,它的作用在於插入符號文檔中指出該值是可選的,但如果起作用,我就不會抱怨。
#Model
newSVM <- list(label="My Model",
type="Regression",
library="kernlab",
loop = NULL,
parameters = prm,
grid = svmGrid,
fit = svmFit,
predict = svmPred,
prob = NULL,
sort = svmSort,
levels = NULL)
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.