> hillary = c("h","evergreen","hillary clinton","hdrclintonemailcom","hdrdintonemailcom")
> dat.from.to[,"h"] = rowSums(dat.from.to[,hillary])
Error in dat.from.to[, hillary] : subscript out of bounds
> dat.from.to["h",] = colSums(dat.from.to[hillary,])
Error in dat.from.to[hillary, ] : subscript out of bounds

求教，做数据分析运行错误，这是为什么？