how to plot histogram of hue value in polar ?
5 views (last 30 days)
Show older comments
Hi
i wants to plot a histogram of hue values in polar . in my 1st image i have plotted histogram of hue values . and now i would like to plot it on polar as shown in figure 2.
please help me .
0 Comments
Accepted Answer
Image Analyst
on 12 Nov 2013
I just adapted Doug's code to use a sample image and I got this:
See code attached below in blue text.
2 Comments
More Answers (2)
Doug Hull
on 11 Nov 2013
Edited: Doug Hull
on 11 Nov 2013
clear
clc
clf
z = peaks(300);
r = z(:,150);
r = r-min(r);
r = r/max(r);
n = numel(r)
cmap = jet(n)
drawWheel(r*0.8,cmap)
Save this file first though:
function drawWheel(r, cmap)
if (any(r > 1) | any(r < 0))
error('R must be a vector of values between 0 and 1')
end
if numel(r) ~= size(cmap,1)
error('Length of r and cmap must be the same')
end
n = numel(r);
innerRadius = 80;
outerRadius = 100;
angles = linspace(0,2*pi,n+1);
newR = innerRadius*(1-r);
for i = 1:n;
drawSpoke(innerRadius, outerRadius, angles(i), angles(i+1), cmap(i,:))
drawSpoke(newR(i) , innerRadius, angles(i), angles(i+1), cmap(i,:))
end
line(0,0,'marker','o')
line(cos(angles)*outerRadius, sin(angles)*outerRadius, 'LineWidth', 3, 'Color', 'k')
line(cos(angles)*innerRadius, sin(angles)*innerRadius, 'LineWidth', 3, 'Color', 'k')
axis equal
function h = drawSpoke(ri,ro,thetaStart,thetaEnd,c)
xInnerLeft = cos(thetaStart) * ri;
xInnerRight = cos(thetaEnd) * ri;
xOuterLeft = cos(thetaStart) * ro;
xOuterRight = cos(thetaEnd) * ro;
yInnerLeft = sin(thetaStart) * ri;
yInnerRight = sin(thetaEnd) * ri;
yOuterLeft = sin(thetaStart) * ro;
yOuterRight = sin(thetaEnd) * ro;
X = [xInnerLeft, xInnerRight, xOuterRight xOuterLeft];
Y = [yInnerLeft, yInnerRight, yOuterRight yOuterLeft];
h = patch(X,Y,c);
set(h,'edgeColor', 'none')
See Also
Categories
Find more on Red in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!