I want to plot the overlapping area of 2 rectangles in a color. I know I can plot the rectangles by using the rectangle command. With rectint I can find out whether they overlap or not.
Is there a specific command for this or does anyone know how I can do this? As you have noticed, I do not have much experience with Matlab.
Code:
A = [0 0 3 3];
B = [2 2 2 2];
hold on;
rectangle('Position',A) %plot rectangle A
rectangle('Position',B) %plot rectangle B
if (rectint(A,B) > 0)
%plot overlapping
end
hold off;
Image:
Assuming the rectangles overlap, the part for the plotting could be done like this:
if (A(1)<=B(1))
intersection(1)=B(1);
intersection(3)=A(1)+A(3)-B(1);
else
intersection(1)=A(1);
intersection(3)=B(1)+B(3)-A(1);
end
if (A(2)<=B(2))
intersection(2)=B(2);
intersection(4)=A(2)+A(4)-B(2);
else
intersection(2)=A(2);
intersection(4)=B(2)+B(4)-A(2);
end
intersectionPlot=rectangle('Position', intersection);
set(intersectionPlot, 'FaceColor', 'r'); % r stands for red, you can choose any other color
So you only want to plot the little rectangle in the middle?
I don't think that there is a builtin function for that, and this is probably the way to go:
Determine the coordinates of the intersection (as long as it are just rectangles this should not be too hard)
Plot the result
Related
I used the answer on Plot vector (or arc) onto a rose plot. MATLAB to plot my rose diagram but my plot looks like this:
My code:
circ_plot(BB,'hist',[],20,true,true,'linewidth',2,'color','r')
hold on
plot([0 cos(mean)*a], [0 sin(mean)*a], 'r')
%// Plot error as many shaded triangles that compose a circular wedge
t = linspace(-Var/2+mean,Var/2+mean,100); %// increase "100" if needed
for k = 1:numel(t)-1
h = patch([0 cos(t(k))*a cos(t(k+1))*a 0], ...
[0 sin(t(k))*a sin(t(k+1))*a 0], [.5 0 0], 'edgecolor', 'none');
%// change color [.5 0 0] to something else if desired. Note also alpha
set(h,'Facealpha',.3) %// make transparent
end
%// Place rose on top by rearranging order of axis children
ch = get(gca,'children');
set(gca,'children',[ch(2:end); ch(1)]);
Any ideas how I get my error shaded area do follow the circumference of the circle rather than being a triangle?
Thanks
I don't know why, but today its works fine. I didn't change anything. Thanks for your reply and offer of help. unfortunately due to the sensitive nature of my data I am unable to post.
thanks again.
I am trying to create a plot that looks like this with rings of constant values (colors) extending from 0 to 100 in 10 unit increments.
Rings of single values extending outward from center
However, my code is not producing this, and I do not know where it has gone wrong.
% values representing the colors that each ring should be
% starting from the center and moving outwards in 10 unit increments.
values = [364,358,354,348,339,335,330,325,320,310];
xCoord = linspace(0,2*pi,10);
yCoord = linspace(0,100,10);
[TH,R] = meshgrid(xCoord,yCoord);
[X,Y] = pol2cart(TH,R);
[Z] = meshgrid(values);
contour_ticks = 300:5:375;
figure
hold on
contourf(X,Y,Z,contour_ticks);
a=gca; cb=colorbar; colormap('jet'); caxis([300 375]);
This produces a plot resembling this:
Incorrect plot
Any ideas what I'm doing wrong? Any help is greatly appreciated. Thanks.
If you just want to plot circles, you can use the following approach:
radii = 100:-10:10; %// descending order, so that bigger circles don't cover small ones
colors = parula(numel(radii)); %// or use some other colormap
for n = 1:numel(radii)
r = radii(n);
rectangle('Position', [-r -r 2*r 2*r], 'Curvature', [1 1], 'FaceColor', colors(n,:),...
'EdgeColor', 'none') %// plot each circle using sequential colors, no edge
hold on
end
axis equal
axis([-1 1 -1 1]*max(radii))
The following code plots 3 points, all in red:
a = reshape([92.571251 94.869889 97.283709 ],[3 1]);
b = reshape([271.000000 296.000000 330.000000 ],[3 1]);
c = reshape([0.916000 0.766000 0.562000 ],[3 1]);
figure(100);
line(b,a,...
'MarkerFaceColor',[1 0 0],...
'Marker','o',...
'LineStyle','none',...
'Color',[1 0 0]);
Is there a way for me to vectorize the red portion of the 'Color' plot style using 'c' such that the first point uses c(1) to replace the 1 so that the color is [0.916 0 0], etc.?
NOTE: This code is a snippet of something much larger that will likely plot 100's or 1000's of points over time on the same plot. I need the color for each point to be set when it's placed on the plot and then not change as other points are added. (If possible)
I do not think a color map is appropriate as I may plot points at the same X,Y coordinates at different times. Sometimes they will be bright, other times dim.
Just trying to not use a loop which would be relatively straight forward.
Thanks!
To colorize the points (and only the points, not the lines in between), you can use the MarkerFaceColor property of the scatter function (or scatter3 in 3D).
For instance:
scatter(a, b, 'MarkerFaceColor', rgb)
where rgb are RGB triplets, or
scatter(a, b, 'MarkerFaceColor', 'flat', 'CData', c)
with c being a vector of values. In this case the colors are mapped onto the current colormap and the range is controled by caxis.
If you want lines between your points, you can simply use a code like this:
hold on
plot(a, b, '-')
scatter(...)
Best,
I have two datasets. One detailing a list of angles (which I am plotting onto a rose plot):
angles
-0.8481065519
0.0367932161
2.6273740453
...
n
The other, detailing directional statistics from this group of angles:
angle,error
-0.848106563,0.8452778824
Where angle essentially defines the directional mean, and error the circular variance, essentially an error bar either side of the angle
I have thus far plotted a rose histogram using the set of angles, as such:
h = rose(angles,36)
I would like to create a plot of the directional statistic angle (it does not need a length/magnitude - just to the edge of the circle plot) with the error around it.
As an example:
I added the lines by hand in Matlab. If possible it would be good to perhaps have shading within the arc too. Alternatively, (and possibly preferred) would be to have just a sliver above the rose plot bins (so it doesn't cover the data) with a centre line (showing the angle and shading surrounding for the error.
Thanks in advance.
How about this?
%// Data
angles = 2*pi*.8*randn(1,1e4);
angle = -0.848106563;
error = 0.8452778824;
%// Plot rose
rose(angles, 36);
axis image %// make axis square
hold on
%// Plot mean
a = axis;
a = a(2); %// size of axis
plot([0 cos(angle)*a], [0 sin(angle)*a], 'r')
%// Plot error as many shaded triangles that compose a circular wedge
t = linspace(-error/2+angle,error/2+angle,100); %// increase "100" if needed
for k = 1:numel(t)-1
h = patch([0 cos(t(k))*a cos(t(k+1))*a 0], ...
[0 sin(t(k))*a sin(t(k+1))*a 0], [.5 0 0], 'edgecolor', 'none');
%// change color [.5 0 0] to something else if desired. Note also alpha
set(h,'Facealpha',.3) %// make transparent
end
%// Place rose on top by rearranging order of axis children
ch = get(gca,'children');
set(gca,'children',[ch(2:end); ch(1)]);
For this to work, you need to use a figure renderer capable of transparency. So you may need to adjust the figure's renderer property.
I was trying use the code shown below to plot in such a way that each iso-surface will be different in color and there will be a color bar at the right. I made a ss(k) color matrix for different colors. Number of iso-surfaces is 10 but I have only 8 colors. That's why I wrote ss(9)='r' and ss(10)='r'.
I need a solution to plot the iso-surface with different color and bar at the right side.
ss=['y','m','c','r','g','b','w','k','r','r']
k=1;
for i=.1:.1:1
p=patch(isosurface(x,y,z,v,i));
isonormals(x,y,z,v,p)
hold on;
set(p,'FaceColor',ss(k),'EdgeColor','none');
daspect([1,1,1])
view(3); axis tight
camlight
lighting gouraud
k=k+1;
end
Another possibility is to draw the patches with direct color-mapping (by setting the property 'CDataMapping'='direct'), while assigning the 'CData' of each patch to an index in the colormap of your choice. This is in fact recommended for maximum graphics performance.
Consider the following example:
%# volumetric data, and iso-levels we want to visualize
[x,y,z,v] = flow(25);
isovalues = linspace(-2.5,1.5,6);
num = numel(isovalues);
%# plot isosurfaces at each level, using direct color mapping
figure('Renderer','opengl')
p = zeros(num,1);
for i=1:num
p(i) = patch( isosurface(x,y,z,v,isovalues(i)) );
isonormals(x,y,z,v,p(i))
set(p(i), 'CData',i);
end
set(p, 'CDataMapping','direct', 'FaceColor','flat', 'EdgeColor','none')
%# define the colormap
clr = hsv(num);
colormap(clr)
%# legend of the isolevels
%#legend(p, num2str(isovalues(:)), ...
%# 'Location','North', 'Orientation','horizontal')
%# fix the colorbar to show iso-levels and their corresponding color
caxis([0 num])
colorbar('YTick',(1:num)-0.5, 'YTickLabel',num2str(isovalues(:)))
%# tweak the plot and view
box on; grid on; axis tight; daspect([1 1 1])
view(3); camproj perspective
camlight; lighting gouraud; alpha(0.75);
rotate3d on
I also included (commented) code to display the legend, but I found it to be redundant, and a colorbar looks nicer.
Matlab usually plots different iso-surfaces in different colors automatically, so you don't need to care about that. What kind of bar do you need? A colorbar or a legend? Either way, it is just to use the colorbar or legend function..
%Create some nice data
[x y z] = meshgrid(1:5,1:5,1:5);
v = ones(5,5,5);
for i=1:5
v(:,:,i)=i;
end
v(1:5,3:5,2)=1
v(1:5,4:5,3)=2
%Plot data
for i=1:5
isosurface(x,y,z,v,i)
end
%Add legend and/or colorbar
legend('one','Two','Three','Four')
colorbar
Since the color bar encodes value->color, it is impossible to do what you ask for, unless there is no intersection in z-values between all pairs of surfaces. So the solution below assumes this is the case. If this is not the case, you can still achieve it by adding a constant value to each surface, so to separate the surfaces along the z axis, and eliminate any intersection.
The solution is based on constructing a colormap matrix of piecewise constant values, distributed similarly to the z values of your surfaces. So for example, if you have 3 surfaces, the first has z values between 1 and 10, the 2nd between 11 and 30, and the 3rd between 31 and 60, you should do something like this (I plot in 2D for simplicity)
r = [1 0 0];
g = [0 1 0];
b = [0 0 1];
cmap = [r(ones(10,1),:); g(ones(20,1),:); b(ones(30,1),:)];
z1 = 1:10;
z2 = 11:30;
z3 = 31:60;
figure; hold on
plot(z1,'color',r)
plot(z2,'color',g)
plot(z3,'color',b)
colorbar
colormap(cmap)
More complex colormaps (i.e, more colors) can be constructed with different mixtures of red, green, and blue (http://www.mathworks.com/help/techdoc/ref/colorspec.html)