如何require一个变量？

HarryZhu

有好多包需要做依赖的判断处理，
depandencies = c("RMySQL","ggplot2")
现在想用require(depandencies)来判断，但是发现 require函数直接将变量识别为字符串了。

这里应该怎么优化呢？

HarryZhu

刚刚make a wheel。

Harry Zhu 13:52:35
# install depandancies
import <- function(packages){
for (i in 1:length(packages)){
package = packages;
char_package = package;
# char_package <- as.character(substitute(char_package))
loaded <- paste("package", char_package, sep = ":") %in% search() # 判断是否有这个包
if(loaded){
library(char_package,character.only = TRUE)
print(paste0("load ",char_package))
}
else{
print(paste0("can not find ",char_package,", we need to install it"));
install.packages(package);
library(char_package,character.only = TRUE)
}
}
}
#
depandancies = c("RMySQL","rjson","plyr","foreach")
import(depandancies)

ryo

俺向来都使用BBmisc，介绍一下： ;-)

> pkgs <- c('RMySQL', 'ggplot2')
> BBmisc::lib(pkgs); rm(pkgs)