ecdfhist - Empirical cumulative distribution function histogram
Syntax
n = ecdfhist(f,x)
n = ecdfhist(f,x,m)
n = ecdfhist(f,x,c)
[n,c] = ecdfhist(...)
ecdfhist(...)
Description
n = ecdfhist(f,x) takes a vector f of
empirical cumulative distribution function (cdf) values and a vector x of
evaluation points, and returns a vector n containing
the heights of histogram bars for 10 equally spaced bins. The function
computes the bar heights from the increases in the empirical cdf,
and normalizes them so that the area of the histogram is equal to
1. In contrast, hist produces
bars whose heights represent bin counts.
n = ecdfhist(f,x,m), where m is
a scalar, uses m bins.
n = ecdfhist(f,x,c), where c is
a vector, uses bins with centers specified by c.
[n,c] = ecdfhist(...) also returns the
position of the bin centers in c.
ecdfhist(...) without output arguments
produces a histogram bar plot of the results.
Examples
The following code generates random failure times and random
censoring times, and compares the empirical pdf with the known true
pdf.
y = exprnd(10,50,1); % Random failure times
d = exprnd(20,50,1); % Drop-out times
t = min(y,d); % Observe the minimum of these times
censored = (y>d); % Observe whether the subject failed
% Calculate the empirical cdf and plot a histogram from it
[f,x] = ecdf(t,'censoring',censored);
ecdfhist(f,x)
set(get(gca,'Children'),'FaceColor',[.8 .8 1])
hold on
% Superimpose a plot of the known population pdf
xx = 0:.1:max(t);
yy = exp(-xx/10)/10;
plot(xx,yy,'r-','LineWidth',2)
hold off
See Also
ecdf, hist, histc
 | ecdf | | end (categorical) |  |
Includes the most popular MATLAB recorded presentations with Q&A sessions led by MATLAB experts.
Get the Interactive Kit
Store 
