CODEWITHSUNDEEP
matlabloops
Minimalist
Minimalist

Reputation: 975

MATLAB: Plot with For Loop Fixed Variables

In MATLAB, I have following output of data from a script:

A1 = [1 2;3 4]
A2 = [2 2; 4 5]
A3 = [3 5; 7 8]

I need to create a for loop to step through the each variable and plot. Something like:

for i = 1:3
plot(A(i))
end

So A1 will generate a plot. A2 will generate a plot. And A3 will generate a plot.

Thanks

Upvotes: 0

Views: 1000

Answers (3)

Franck Dernoncourt
Franck Dernoncourt

Reputation: 83457

Loop using eval (will emulate variable variable) and figure (will create a figure for each A):

A1 = [1 2;3 4];
A2 = [2 2; 4 5];
A3 = [3 5; 7 8];

for i = 1:3
    figure(i);
    eval(['plot(A' num2str(i) ');'])
end

If you have many As you might want to save the plots automatically, by inserting the following line right after the eval line in the loop:

print('-dpng','-r100',['A' int2str(i)])

Upvotes: 1

Dan
Dan

Reputation: 45762

I suggest you alter the script that outputs those variables to rather stick them in a cell array or a struct.

If that's not possible then if there are only 3 I would suggest you stick them in a cell array manually i.e. A{1} = A1; A{2} = A2; A{3} = A3

Only if you really really can't do either of those, you should consider using eval

for ii = 1:n
    eval(['plot(A', num2str(ii), ')']);
end

to debug I suggest replacing eval with disp to make sure you are generating the right code

Upvotes: 5

Shai
Shai

Reputation: 114976

What you can do is use eval

for ii = 1:3
   cmd = sprintf('plot( A%d );', ii );
   eval( cmd );
end

However, using eval is not recommended. The best way is if you can alter the code generating A1...A3, so it can either create a cell array A{1},...A{3}, or even struct fields S.A1,...,S.A3.

Upvotes: 5

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