R - 粘贴命令以调用矩阵名称答案

【问题标题】：R - Paste command to call a matrix nameR - 粘贴命令以调用矩阵名称
【发布时间】：2019-07-28 14:54:30
【问题描述】：

我对一个指定的国家/地区有以下命令，这里是 AT，我想做更多。

c1<-grep(pattern="AT",x=names(climatebig3),value=TRUE)
c1matAT<-climatebig3[c1]
c1matAT<-c1matAT[,which(apply(!is.na(c1matAT[1:27,]),2,all))]

获取国家向量并在前两个命令上循环它有效，但不适用于第三个。

countries<-c("AT","BE","BG","CZ","DK","DE","EE","IE","EL","ES","FR","HR","IT","CY","LV","LT","LU","HU","MT","NL","PL","PT","RO","SI","SK","FI","SE","UK")


for (i in 1:28){assign(paste("c1mat",as.character(countries[[i]]),sep=""),climatebig3[,grep(pattern=as.character(countries[[i]]),x=names(climatebig3),value=TRUE)])

assign(paste("c1mat",as.character(countries[[i]]),sep="", paste("c1mat",as.character(countries[[i]]),sep="")[,which(apply(!is.na(as.character(paste("c1mat",as.character(countries[[i]]),sep=""))[1:27,]),2,all))])}

由于某种原因，粘贴命令只是调用了矩阵的名称，并没有将其识别为代码最后一行中的矩阵。提前谢谢大家！

【问题讨论】：

标签： r string loops paste assign

【解决方案1】：

不要（永远）使用assign。改用列表：

#Create an empty named list the same length as the number of countries
c1mat_list <- setNames(vector("list",length(countires)),countries)

#Loop through countries and populate the list
for (x in countries){
  c1 <- grep(pattern= x,x=names(climatebig3),value=TRUE)
  c1mat_list[[x]] <-climatebig3[c1]
  #etc.
}

【讨论】：