Plotting cell arrays, arbitrary size

I'm trying to plot an arbitrary number of curves contained in a 2xN cell array. Row 1 is the XData, Row 2 contains the YData. I have verified all vectors (of doubles) are the same length.

The code:

[C{1,k},C{2,k}]=MyFun(...);

plot(C{:})

returns the error "Too many input arguments." I have tested with the size of C as 2x1 and 2x2.

I ensure that the output vectors generated in MyFun are row vectors with (though I think this is unnecessary):

z=reshape(z,[1 numel(z)]);

Oddly enough, I have taken this idea (plot(C{:})) from other code that works perfectly.

Any thoughts as to what is causing the error and how to fix?

Answer 1

[Jan]

Please post the type and size of the two outputs of your MyFun function and explain, what "k" is. If "plot(C{:})" works depends on the contents of the cell C.

Perhaps this works - but this is pure guessing:

plot(C{:, k})

I have no idea, what z is and why you have to reshape it.

[Benjamin]

Sorry,

That was a little vague now that I read it again. Here are some more details.

[n,z]=MyFun(a,b)

where a, b are scalars and

n, z are row vectors of known, equal length. Just before the function returns, I ensure that n and z are row vectors (with reshape), though I think this step is unnecessary.

This is how MyFun is invoked:

a=[1,2];

b=[3,4];

for k=1:length(c)

[C{1,k},C{2,k}]=MyFun(a(k),b(k));

end

plot(C{:})

a and b can be any length as long as they are the same length. Therefore, the cell array C can be 2xN, where N is the length of a and b. When plotting, I want N lines shown. I know I can achieve this using "hold", but would like the more elegant solution.

Thanks!

Cheers,

Ben

[Benjamin]

Mistake found. Fix:

for k=1:length(a)

[C{1,k},C{2,k}]=MyFun(a(k),b(k));

end

[Benjamin]

Just a mistake in the write up. Not in the code. I'm still having the error problem.

[Jan]

Do the vecors in C all have the same length? If so, you can create a matrix instead:

for k = length(c):-1:1 % Backwards for pre-allocation

[C1(k, :), C2(k, :)] =MyFun(a(k), b(k));

end

Answer 2

[Benjamin]

Turns out plotting a cell array using "plot(C{:})" works perfectly well...so long as you haven't overloaded the plot function.

I accidentally named one of my functions "plot" in the same .m file. It was declared "function []=plot()". Because it was in the same .m file, it took precedence over the built-in function AND since I had declared zero inputs, any number of inputs would give the error I was seeing!

I found my error late last night.

Thank you for all your help! Ben