| MATLAB Function Reference |
histogram2
Compute a two dimensional histogram
Syntax
[result,descriptor] = histogram2(x,y) [result,descriptor] = histogram2(x,y,descriptor)
Description
The discriptor describes the cells of the histogram. The
discriptor consists of two row vectors with three elements
[lowerx,upperx,ncellx;lowery,uppery,ncelly]. The default values are
lowerx=min(x)-deltax/2, upperx=max(x)+deltax/2 and
ncellx=ceil(length(x)^(1/3)), where
deltax=(max(x)-min(x))/(length(x)-1) and similar for y.
Its assumed that lowerx < upperx, lowery <
uppery, ncelly >= 1,
ncelly >= 1 and length(x) == length(y). Futhermore its assumed that both x
and y are row
vectors.
The result is a matrix vector containing the histogram of
x and y.
The indices (indexx,indexy) of the histogram cells are computed by indexx = round( (x(i)-lowerx) / (upperx-lowerx) * ncellx
) + 1/2 and indexy = round( (x(i)-lowery) / (uppery-lowery) * ncelly
) + 1/2. If one of the indices is out of the range 1 <= indexx <=
ncellx or 1 <= indexy <=
ncelly, consequently x(i) < lowerx,
upperx <= x(i),y(i) < lowery or
uppery <= y(i), the elements x(i) and
y(i) are excluded from the histogram.
See Also
Literature
None
Source code
| MATLAB Function Reference |