条件的长度> 1,只使用第一个元素

时间:2014-04-26 20:29:22

标签: r if-statement conditional calculated-columns

我有一个数据帧,旅程:

> head(trip.mutations)
  Ref.y Variant.y
1 T     C 
2 G     C 
3 A     C  
4 T     C 
5 C     A 
6 G     A 

我想添加第三列mutType,遵循以下规则:

for (i in 1:nrow(trip)) {
   if(trip$Ref.y=='G' & trip$Variant.y=='T'|trip$Ref.y=='C' & trip$Variant.y=='A') {
      trip[i, 'mutType'] <- "G:C to T:A"
   }
   else if(trip$Ref.y=='G' & trip$Variant.y=='C'|trip$Ref.y=='C' & trip$Variant.y=='G') {
      trip[i, 'mutType'] <- "G:C to C:G"
   }
   else if(trip$Ref.y=='G' & trip$Variant.y=='A'|trip$Ref.y=='C' & trip$Variant.y=='T') {
      trip[i, 'mutType'] <- "G:C to A:T"
   }
   else if(trip$Ref.y=='A' & trip$Variant.y=='T'|trip$Ref.y=='T' & trip$Variant.y=='A') {
      trip[i, 'mutType'] <- "A:T to T:A"
   }
   else if(trip$Ref.y=='A' & trip$Variant.y=='G'|trip$Ref.y=='T' & trip$Variant.y=='C') {
      trip[i, 'mutType'] <- "A:T to G:C"
   }
   else if(trip$Ref.y=='A' & trip$Variant.y=='C'|trip$Ref.y=='T' & trip$Variant.y=='G') {
      trip[i, 'mutType'] <- "A:T to C:G"
   }
}

但是我收到了错误:

Warning messages:
1: In if (trip$Ref.y == "G" & trip$Variant.y == "T" | trip$Ref.y ==  ... :
  the condition has length > 1 and only the first element will be used

我不认为我的逻辑陈述应该是生成向量,但也许我错过了一些东西。 trip $ mutType 应该最终看起来像这样:

mutType
A:T to G:C
G:C to C:G
A:T to C:G
A:T to G:C
G:C to T:A
G:C to A:T

有人能发现这里有什么问题吗?我需要||而不是|也许?

2 个答案:

答案 0 :(得分:42)

您收到错误,因为if只能评估长度为1的logical向量。

也许您错过了&|)和&&||)之间的区别。较短的版本按元素方式工作,较长的版本仅使用每个向量的第一个元素,例如:

c(TRUE, TRUE) & c(TRUE, FALSE)
# [1] TRUE FALSE

# c(TRUE, TRUE) && c(TRUE, FALSE)
[1] TRUE

您根本不需要if声明:

mut1 <- trip$Ref.y=='G' & trip$Variant.y=='T'|trip$Ref.y=='C' & trip$Variant.y=='A'
trip[mut1, "mutType"] <- "G:C to T:A"

答案 1 :(得分:3)

像sgibb一样,这是一个问题,它与|无关或||。

以下是解决问题的另一种方法:

for (i in 1:nrow(trip)) {
  if(trip$Ref.y[i]=='G' & trip$Variant.y[i]=='T'|trip$Ref.y[i]=='C' & trip$Variant.y[i]=='A') {
    trip[i, 'mutType'] <- "G:C to T:A"
  }
  else if(trip$Ref.y[i]=='G' & trip$Variant.y[i]=='C'|trip$Ref.y[i]=='C' & trip$Variant.y[i]=='G') {
    trip[i, 'mutType'] <- "G:C to C:G"
  }
  else if(trip$Ref.y[i]=='G' & trip$Variant.y[i]=='A'|trip$Ref.y[i]=='C' & trip$Variant.y[i]=='T') {
    trip[i, 'mutType'] <- "G:C to A:T"
  }
  else if(trip$Ref.y[i]=='A' & trip$Variant.y[i]=='T'|trip$Ref.y[i]=='T' & trip$Variant.y[i]=='A') {
    trip[i, 'mutType'] <- "A:T to T:A"
  }
  else if(trip$Ref.y[i]=='A' & trip$Variant.y[i]=='G'|trip$Ref.y[i]=='T' & trip$Variant.y[i]=='C') {
    trip[i, 'mutType'] <- "A:T to G:C"
  }
  else if(trip$Ref.y[i]=='A' & trip$Variant.y[i]=='C'|trip$Ref.y[i]=='T' & trip$Variant.y[i]=='G') {
    trip[i, 'mutType'] <- "A:T to C:G"
  }
}
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