问题描述
在gnuplot中，有什么方法可以在变量中指定命令，例如：
command = "plot x**2 with lines"
，然后使用以下命令“执行”该命令：
exec command
解决方法
使用eval：
echo help eval | gnuplot
The `evaluate` command executes the commands given as an argument string.
Newline characters are not allowed within the string.
Syntax:
eval <string expression>
This is especially useful for a repetition of similar commands.
Example:
set_label(x,y,text) \
= sprintf("set label '%s' at %f,%f point pt 5",text,x,y)
eval set_label(1.,1.,'one/one')
eval set_label(2.,'two/one')
eval set_label(1.,2.,'one/two')
Please see `substitution macros` for another way to execute commands
from a string.