如何创建以希腊符号作为列名的数据框？

Question

I am trying to build a data frame with greek letters as the column names, but using expression() does not seem to work.

I create the data frame like so:

random_parameter<-rep(c(0,.5,1),3)
radiusCluster_parameter<-rep(c(100,300,600),each=3)
Cluster_metric<-rep(NA,length(radiusCluster_parameter))
parameter_table<-data.frame(random_parameter,radiusCluster_parameter,Cluster_metric)
colnames(parameter_table)<-c("R", expression(rho),expression(sigma))

But this creates a data frame with the column names "R","rho" and "sigma". I'd prefer the actual "R", "ρ" and "σ".

Answer 1

Just add the greek character set so it can read the greek letters

Sys.setlocale(category = "LC_ALL", locale = "Greek")