I am using Plots.jl with the GR backend.
For whatever, I cannot seem to be able to plot! inside a for-loop:
using Plots
fn(m,x) = m*x
plot([0, 10], [fn(1, 0), fn(1, 10)])
for m in 2:4
plot!([0, 10], [fn(m, 0), fn(m, 10)])
end
Oddly enough, the same thing without using a cycle works:
using Plots
fn(m,x) = m*x
plot([0, 10], [fn(1, 0), fn(1, 10)])
plot!([0, 10], [fn(2, 0), fn(2, 10)])
plot!([0, 10], [fn(3, 0), fn(3, 10)])
plot!([0, 10], [fn(4, 0), fn(4, 10)])