如果循環參數長度爲零，錯誤

Question

我有以下簡單的代碼，我面對以下錯誤，任何人都可以幫我弄清楚嗎？它基本上應該計算使用兩個向量的得分和b輸入：

Error in if (b[i] == 1) { : argument is of length zero 

我的代碼是：

require("Matrix") 


# input vectors 
a<-c(0.01,0.02,0.09,0.81,0.54,0.04,0.05,0.11,0.44,0.08,0.03,0.06,0.07,0.22,0.21,0.34,0.77,0.89,0.45,0.13,0.32,0.42,0.21,0.73,0.66,0.88) 

b<-c(0,1,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0) 

#order the singificance vector together with pathway vector with increasing P-value 
sort(a, decreasing=F) 

b[order(a,decreasing =F)] 

GSEA<-function(a,b){ 
m=length(a) 
l=nnzero(b) 
score<-c() 

for (i in a){ 
    if(b[i]==1){ 
    score= + (m-l) 
}else{score=score-l} 

} 

} 
total<-c() 
total.x<-c(1:m) 
total.y<-score 

Answer 1

您正在嘗試使用非整數值作爲提取指標，當你說if(b[i]==1)。您可能需要for(i in seq_along(a))而不是for(i in a)。

見，例如：

> if((1:3)[.2]==1) 'hello world' 
Error in if ((1:3)[0.2] == 1) "hello world" : argument is of length zero