Plotting Legend in a For Loop

I am trying to plot multiple lines on a plot, and want my legend to reflect those line styles as well as colors. I am using the following for loop-

for i=2:5
  sigma_level=i; hold on;
  h1=plot(x1,[meanf-sigma_level*stdf meanf-sigma_level*stdf],'Color',rand(1,3));
  legendInfo{i-1}=[num2str(i),'\sigma'];
end;
legend(legendInfo)

My issue is that the legend does not reflect the lines plotted, because I'm not using the h1 variable to identify it in the legendInfo. If I use

legendInfo{i-1}=[h1,num2str(i),'\sigma']

I get the following error-

Error using matlab.graphics.chart.primitive.Line/horzcat
Conversion to matlab.graphics.chart.primitive.Line from char is not possible.
Error in test (line 33)
legendInfo{i-1}=[h1,num2str(i),'\sigma'];

What is the possible solution to fix this?

Thanks!

Answer 1

[dpb]

plot returns a line handle; you're overwriting the previous handles on the subsequent passes thru the loop...

j=0;  % accumulator; not sure why ran loop 2:5??
for i=2:5
  j=j+1;
  sigma_level=i;
  h(j)=plot(x1,[meanf-sigma_level*stdf meanf-sigma_level*stdf],'Color',rand(1,3));
  if j==1, hold on, end  % only set hold after first plot...
  legendInfo{j}=[num2str(i),'\sigma'];
end;
legend(h,legendInfo)

[Mridul Garg]

Thank you, this works perfectly fine.

PS- It's specific to the problem so I need to run it from 2-5.

[dpb]

The magnitude of the multiplier is 2:5; that doesn't mean the loop had to be written that way (and thereby complicate the indexing).