MATLAB: Bin X data, sum corresponding Y data and then plot.

dataplot

I have X data ranging from 0 to 999 and corresponding Y data. I want to bin the X data from 0 to 2000 with a bin size of 10. Then accumulate corresponding Y data in the respective bins. For example, X data from 0.1 to 10 should be taken as 10; 10.01 till 20 should be taken as 20 etc. The Y data in the same interval should be summed up and put in the corresponding bins. At the end, I want to plot X,Y . Please help me to code this… thank you.

Best Answer

binnum = ceil(X/10);
binsum = accumarray(binnum(:), Y(:));
plot((1:size(binsum,1))*10, binsum);

Related Solutions

MATLAB: Finding index and count of values in an interval

This should do the job

x = [1 2 3 4 5];
for i = 1:numel(x)-1
  [val ind_firstentry(i)] = min(hwrect(x(i)-y)); 
  if y(ind_firstentry(i)) >= x(i+1)
    ind_firstentry(i) = []; % remove entry out of bounds
  end
end
disp(num2str(ind_firstentry))

With an additional little helper function

function x = hwrect(x)
%HWRECT  Half wave rectification: negative elements are set to zeros.
%   HWRECT(X) = max(x, 0).
x(find(x < 0)) = 0;

MATLAB: Equal elements in historgam bins

nbin = 10;
y = quantile(x,nbin-1);
[counts, Id] = histc([-inf; y(:); inf]);

quantile returns N entries part way through the data. If you look at the example quantile(x,4) and notice the material about the equivalent probabilities, you can see that argument N would be for dividing into N+1 equal pieces.

histc uses the values passed as being the edges, and any value less than the first provided edge is not counted, so to count from the lowest value, prefix the quantile result with either min(x) or with -inf.

For histc, the last bin is to be used only for values that exactly equal the last edge value; the last bin is not used for all x from the last value upwards. For symmetry with the possibility of using min(x) as the first edge value, you might be tempted to use max(x) as the last edge value. However that would mean that the last bin would count only values exactly equal to max(x), so instead of max(x) use +inf as the last edge. This does theoretically lead to the possibility of an unexpected match against inf, if the input just happens to contain inf, but if that concerns you, you could easily adjust for it.

Best Answer

Related Solutions

MATLAB: Finding index and count of values in an interval

MATLAB: Equal elements in historgam bins

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