我目前正在尝试更新任何行的“e”列
for(col in colnames(df))
{
df$e[is.na(df[col])] <- paste(col, "empty - excluded:", " ")
}
这有效。但是,我如何将新文本附加到单元格中的当前值?
我习惯了SQL:
UPDATE df SET e = e & " excluded" WHERE NZ(col, '') = ''
也许这样(未经测试)
df[,"e"] <- ""
for (col in colnames(df)) {
idx <- which(is.na(df[,col])
df[idx, "e"] <- paste(df[idx, "e"], col, sep=", ")
}
df[,"e"] <- ifelse(df[,"e"]!="", paste(df[,"e"], "empty - excluded")
这将首先收集NA列,然后添加字符串“empty - excluded”。