Graphing ruby gem for mac?

I'm fairly new to programming with ruby and have been trying to install a gem so that I can make graphs. 开发者_运维问答I've tried unsuccessfully with gruff and gnuplot as I have run into errors for both. can someone give me a detailed step by step on how install or a link to one? thanks

there is a discussion about it here

What graphing packages/APIs exist for Ruby?