MATLAB: To create Polar Shaded plot

polar shaded plot

X,Y,Z DATA ..all n*1 array

X is angle, with NEWS convention, Y is radius, Z is data.

I need shaded plot of data, onto a polar plot of radius information in Y angle information in X and data information in Z

Basically a rose plot sans the discreet histogram.

Sorry cant figure out any solution.

Best Answer

If you don't see a polar plot which does what you want, you can use the pol2cart function to get to any of the Cartesian techniques, such as the ones I described in this blog post.

% Made up data
npts = 200;
theta = 2*pi*rand(npts,1);
r = rand(npts,1);
v = cos(theta) .* sin(pi*r);
% Convert to cartesian
[x,y] = pol2cart(theta,r);
% Interpolate onto grid
[xg,yg] = meshgrid(linspace(-1,1,125));
F = scatteredInterpolant(x,y,v);
% Mask out extrapolation
b = boundary(x,y);
inmask = inpolygon(xg(:),yg(:), x(b),y(b));
vg = F(xg,yg);
vg(~inmask) = nan;
% Call pcolor
polar(nan,nan)
hold on
h = pcolor(xg,yg,vg);
h.EdgeColor = 'none';
colorbar

Related Solutions

MATLAB: How to connect the points in an polar plot

Have you tried to connect your points with splines? See http://www.mathworks.se/help/matlab/examples/splines-in-two-dimensions.html for an example.

MATLAB: How to make section distance of temperature

Simply skipping the loop and changing the line

inmask = inpolygon(xg(:),yg(:), bx , by );%define which pixel exist in the polygon

inmask = inpolygon(xg(:),yg(:), x(b) , y(b) );%define which pixel exist in the polygon

Gives more or less the desired result. The boundary() function does not seem to capture all the corners though.

Here is a better method which works because you are working with grouped data, i.e. several measurements on the exact same depth.

data=xlsread('ctd_data.xlsx');
x=data(:,5); %first colum in excel file, as distance
y=data(:,3)*-1;%second colum in excel file, as depth
c=data(:,4); %c is the concentration of  Temperature
figure(1)
scatter(x,y,30,c,'filled')
colorbar
axis tight; hold on
shading interp
ylabel('Depth (m)'); 
title('Temperature distribution');
figure(2)
[xg,yg] = meshgrid(min(x):0.1:max(x),min(y):0.1:max(y)); %make a grid to contain x,y
f = scatteredInterpolant(x,y,c,'linear'); %assign c values to x y
vg = f(xg,yg);% assign c values to finer pixel xg yg
%find boundary
[g,xd] = findgroups(x)
yd_top = splitapply(@min,y,g)
yd_bot = splitapply(@max,y,g)
yd = [yd_top;flip(yd_bot)];
xd = [xd;flip(xd)]
inmask = inpolygon(xg(:),yg(:), xd , yd );%define which pixel exist in the polygon
vg(~inmask) = nan; %NAN values for the pixel not in the polygon
h = pcolor(xg,yg,vg); %ploting in 2D of vg by color
h.EdgeColor = 'none'; %to get rid off the edge line
h.FaceColor = 'interp';
colorbar
xlabel('Distance (km)'); 
ylabel('Depth (m)');

cheers!

Best Answer

Related Solutions

MATLAB: How to connect the points in an polar plot

MATLAB: How to make section distance of temperature

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