One approach:
x = randn(100,1); % Create Data
binrng = linspace(-5, 5, 26); % Choose Bin Centres
hx = histc(x, binrng); % Histogram Counts
chx = cumsum(hx)/numel(x); % Cumulative Sum
figure
plot(binrng, chx)
grid
In histc, the bin ranges are the bin centres. It calculates the bin edges from them.
Experiment to get the result you want.
