short way to bar plot a discretize vector?

לק"י

Hello!

I want to take a vector A, and bar plot it using specific bins (defiend by 'edges' vector). I want the plot to show the sum of values that belong to each bin. Not the number of values like histogram does.

I started to write a code:

dsc=discretize(A, edges);
barpltcll=num2cell(edges);
for i=length(edges) %this part creates cell array that holds all the sum of values that fall in the bins.
    barpltcll(2,i)=sum(A(dsc(i)))...

but I thought maybe there is shorter way to do it. I would love to know about it, like turn an option in the histogram() comamnd to show the sum of values that fell into the bin rather then the counts (number of values). :)

Thanks,

Amit.

Answer 1

[Jan]

A     = rand(1, 100);
edges = linspace(0, 1, 6);
dsc   = discretize(A, edges);
result = accumarray(dsc(:), A(:));  % Default function: @sum
bar(edges(1:end-1), result)

[Amit Ifrach]

לק"י

Hi Jan, thanks for the quick answer!

May I just ask another thing.. when using accumarray i got this:

Error using accumarray
First input SUBS must contain positive integer subscripts.

Any idea why do I got it?

I read a bit about it, something about 'unique' values which I belive I don't have and as far as I saw, there are only positive integers in the dsc variable, like here:

Accumarray error: First input SUBS must contain positive integer subscripts. - MATLAB Answers - MATLAB Central (mathworks.com)

Thanks :)

[Amit Ifrach]

לק"י

Sorry, had to find the nan (max value).

Thank :)

[Jan]

@Amit Ifrach: What does this mean: לק"י

[Amit Ifrach]

Hi @Jan,

It's Yemenite jews way to start a writing (translates somewhat to for the hope for g-d)

Amit :)

[Jan]

@Amit Ifrach: Thanks for the explanation. I assume I guess correctly, what "g-d" is.