Having trouble using the histogram function

I have been trying to generate a histogram of gradients for an input image. The image is given to a function, which then finally returns a column vector X. However, when I say histogram(X), I get the following error:

>> histogram(x)
Not enough input arguments.

Error in histogram (line 27)
binSize = pi / numBins;

line 27 is

% Compute the bin size in radians. 180 degress = pi.
binSize = pi / numBins;

I have even tried copying and running the example histogram codes on the documentation page, but all return the exact same error. I'm pretty sure they should work without me having to give any input arguments. Please let me know what I'm missing, I know it must be something pretty silly.

[Adam Danz]

1) What version of matlab are you using? (run ver() if you don't know).

2) can you share your column vector (or at least part of it)?

[edit]

3) see Steven Lord's answer - my money's on that.

[Supriya Prasad]

Thank you for your help!

Answer 1

[Steven Lord]

Are you calling the histogram function included in MATLAB, one that you wrote, one that you downloaded from somewhere, or one someone gave you? To check this use the which function.

which -all histogram

I don't think the code you posted is part of the histogram function included in MATLAB. If that which command shows one that is outside the matlabroot directory, rename or remove it.

[Supriya Prasad]

Thank you so much! You're right, unfortunately I'd named another file in the same directory as histogram.m :) Lesson learned, thanks again!