i have this problem i want to make a color of errobars different from the color of my graph
there is the code i have tried
pp=errorbar(x,testMatriceFluxSortie/ValeurFluxSortie(1,1),err)
pp.Color=[255 0 1]./255;
But it gives me this all in red
my graph
you can always use hold on and plot only the x,y data after the errorbar was plotted, for example:
x = 1:10:100;
y = [20 30 45 40 60 65 80 75 95 90];
err = 8*ones(size(y));
errorbar(x,y,err,'or'); hold on
plot(x,y,'b');
Related
I have a discrete signal x of length N traced in MATLAB using the command
stem(abs(x)); axis([0 N+6 0 4]);
The resulted figure is shown below:
My question I need only some values corresponding for example to index [7 10 11 12 15 18 48 50 52 60] to be colored with different color , let's say with red.
How can I do that into my figure ?
Using Multiple Plots by hold on and Matrix Indexing
You could possibly and alternatively place a plot on top of plot by using hold on. This does require an adjustment where you need a vector in this case Sample and Indices which specify the sample number/data point index. You can also use matrix indexing to get the amplitude/data points corresponding to the key point, Indicies.
%Vector relating to the sample/data point number%
Sample = linspace(1,70,70);
%Random test data%
X = randi([0,2],1,70);
stem(Sample,X);
hold on
%Key indices to change colour%
Key_Indices = [7 10 11 12 15 18 48 50 52 60];
%Matrix indexing to get values/amplitudes corresponding to key indices%
X_Prime = X(Key_Indices);
stem(Key_Indices,X_Prime,'r');
axis([0 70 0 3]);
hold off
Ran using MATLAB R2019b
This code makes just the circles red and not the stems
plot with selected red circles
%Vector relating to the sample/data point number
Sample = linspace(1,70,70);
%Random test data
X = randi([0,2],1,70);
stem(Sample,X);
%Key indices to change color
Key_Indices = [7 10 11 12 15 18 48 50 52 60];
line(Sample(Key_Indices), X(Key_Indices), 'linestyle', 'none', 'marker', 'o', 'color', 'r')
axis([0 70 0 3])
grid on
I have a polar plot that has colored contours. I cannot figure out how to add my axis. The code is below:
close all
data1 = xlsread('C:\Users\Desktop\practice.xlsx','theta');
data2 = xlsread('C:\Users\Desktop\practice.xlsx','r');
data3 = xlsread('C:\Users\Desktop\practice.xlsx'','z');
t = data1(1,:);
r = data2(:,1);
z = data3(:,:);
figure(1)
title('Displacement')
polarcont(r,t,z)
myColorMap = colormap;
myColorMap(1,:) = [1 1 1];
colormap(myColorMap);
colorbar;
caxis([0 25]);
beta = 0.9;
brighten(beta)
From here I cannot figure out how to plot my axes. For instance at theta=0, I would like [100], etc. Whenever I try what usually works,
thetaticks([0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345])
rticks([100 200 300])
rticklabels({'100 eV','200 eV','300 eV'})
ax = gca;
ax.ThetaAxis.TickLabelInterpreter = 'latex';
ax.ThetaTickLabel = {'[100]','','','[101]','','','[001]','','','[$\overline{1}$01]','','','[$\overline{1}$00]','','','[$\overline{1}$0$\overline{1}$]','','','[00$\overline{1}$]','','','[10$\overline{1}$]','','','[$\overline{1}$0$\overline{1}$]'};
I just get riddled with errors involving trying to use polar axes on a cartesian chart. I can plot circles below which can give me the different r mag, but seems kind of a silly way to do it to me: (below)
plotting_circle(0,0,100);
plotting_circle(0,0,200)
plotting_circle(0,0,300)
plotting_circle(0,0,400)
axis equal
axis off
I have a series of ordered points (X, Y, Z) and I want to plot a 3D histogram, any suggestions?
I'm trying to do it by this tutorial http://www.mathworks.com/help/stats/hist3.html , but points are random here and presented as a function. My example is easier, since i already know the points.
Furthermore, depending on the number value of Z coordinate, i'd like to colour it differently. E.g. Max value - green, min value - red. Similar as in this case Conditional coloring of histogram graph in MATLAB, only in 3D.
So, if I have a series of points:
X = [32 64 32 12 56 76 65]
Y = [160 80 70 48 90 80 70]
Z = [80 70 90 20 45 60 12]
Can you help me with the code for 3D histogram with conditional coloring?
So far the code looks like this:
X = [32 64 32 12 56 76 65];
Y= [160 80 70 48 90 80 70];
Z= [80 70 90 20 45 60 12];
A = full( sparse(X',Y',Z'));
figure;
h = bar3(A); % get handle to graphics
for k=1:numel(h),
z=get(h(k),'ZData'); % old data - need for its NaN pattern
nn = isnan(z);
nz = kron( A(:,k),ones(6,4) ); % map color to height 6 faces per data point
nz(nn) = NaN; % used saved NaN pattern for transparent faces
set(h(k),'CData', nz); % set the new colors
end
colorbar;
Now I just have to clear the lines and design the chart to make it look useful. But how would it be possible to make a bar3 without the entire mesh on 0 level?
Based on this answer, all you need to do is rearrange your data to match the Z format of that answer. After than you might need to remove edgelines and possibly clear the zero height bars.
% Step 1: rearrange your data
X = [32 64 32 12 56 76 65];
Y= [160 80 70 48 90 80 70];
Z= [80 70 90 20 45 60 12];
A = full( sparse(X',Y',Z'));
% Step 2: Use the code from the link to plot the 3D histogram
figure;
h = bar3(A); % get handle to graphics
set(h,'edgecolor','none'); % Hopefully this will remove the lines (from https://www.mathworks.com/matlabcentral/newsreader/view_thread/281581)
for k=1:numel(h),
z=get(h(k),'ZData'); % old data - need for its NaN pattern
nn = isnan(z);
nz = kron( A(:,k),ones(6,4) ); % map color to height 6 faces per data point
nz(nn) = NaN; % used saved NaN pattern for transparent faces
nz(nz==0) = NaN; % This bit makes all the zero height bars have no colour
set(h(k),'CData', nz); % set the new colors. Note in later versions you can do h(k).CData = nz
end
colorbar;
I have an image that I opened in Matlab using imshow and I want to replace the color of every pixel with value (140,50,61) with a new color (150,57,80). If anyone could please advise how I can do this.
Assuming A to be the input image data, this could be one approach -
%// Initialize vectors for old and new pixels tuplets
oldval = [140,50,61]
newval = [150,57,80]
%// Reshape the input array to a 2D array, so that each column would
%// reprsent one pixel color information.
B = reshape(permute(A,[3 1 2]),3,[])
%// Find out which columns match up with the oldval [3x1] values
matches = all(bsxfun(#eq,B,oldval(:)),1)
%// OR matches = matches = ismember(B',oldval(:)','rows')
%// Replace all those columns with the replicated versions of oldval
B(:,matches) = repmat(newval(:),1,sum(matches))
%// Reshape the 2D array back to the same size as input array
out = reshape(permute(B,[3 2 1]),size(A))
Sample run -
>> A
A(:,:,1) =
140 140 140
40 140 140
A(:,:,2) =
50 20 50
50 50 50
A(:,:,3) =
61 65 61
61 61 61
>> out
out(:,:,1) =
150 140 150
40 150 150
out(:,:,2) =
57 20 57
50 57 57
out(:,:,3) =
80 65 80
61 80 80
bsxfun is the way I would have solved it. However, if you aren't familiar with it, you can extract each channel from your image, use three logical masks for each channel and combine them all using logical AND. Doing AND will find those pixels in your image that looks for that particular RGB triple.
As such, we set the outputs of each channel accordingly and reconstruct the image to produce the output.
Therefore, given your input image A, one could do:
red = A(:,:,1); green = A(:,:,2); blue = A(:,:,3);
mred = red == 140; mgreen = green == 50; mblue = blue == 61;
final_mask = mred & mgreen & mblue;
red(final_mask) = 150; green(final_mask) = 57; blue(final_mask) = 80;
out = cat(3, red, green, blue);
I am struggling with the concepts behind plotting a surface polar plot.
I am trying to plot the values measured by a sensor at a combination of different angles over a hemisphere.
I have an array containing the following information:
A(:,1) = azimuth values from 0 to 360º
A(:,2) = zenith values from 0 to 90º
A(:,3) = values measured at the combination of angles of A(:,1) and A(:,2)
For example, here is a snippet:
0 15 0.489502132167206
0 30 0.452957556748497
0 45 0.468147850273115
0 60 0.471115818950192
0 65 0.352532182508945
30 15 0.424997863795610
30 30 0.477814980942155
30 45 0.383999653859467
30 60 0.509625464595446
30 75 0.440940431784788
60 15 0.445028058361392
60 30 0.522388502880219
60 45 0.428092266657885
60 60 0.429315072676194
60 75 0.358172892912138
90 15 0.493704001125912
90 30 0.508762762699997
90 45 0.450598496609200
90 58 0.468523071441297
120 15 0.501619699042408
120 30 0.561755273071577
120 45 0.489660355057938
120 60 0.475478615354648
120 75 0.482572226928475
150 15 0.423716506205776
150 30 0.426735372570756
150 45 0.448548968227972
150 60 0.478055144126694
150 75 0.437389584937356
To clarify, here is a piece of code that shows the measurement points on a polar plot.
th = A(:,1)*pi/180
polar(th,A(:,2))
view([180 90])
This gives me the following plot:
I would like now to plot the same thing, but instead of the points, use the values of these points stored in A(:,3). Then, I would like to interpolate the data to get a colored surface.
After some research, I found that I need to interpolate my values over a grid, then translate to Cartesian coordinates. From there I do not know how to proceed. Could someone point me in the right direction?
I have trouble getting the concept of the interpolation, but this is what I have attempted:
x1 = linspace(0,2*pi,100)
x2 = linspace(0,90,100)
[XX,YY] = meshgrid(x1,x2)
[x,y] = pol2cart(th,A(:,2))
gr=griddata(x,y,A(:,3),XX,YY,'linear')
With this piece of code, your example data points are converted into cartesian coords, and then plotted as "lines". The two tips of a line are one data point and the origin.
az = bsxfun(#times, A(:,1), pi/180);
el = bsxfun(#times, A(:,2), pi/180);
r = A(:,3);
[x,y,z] = sph2cart(az,el,r);
cx = 0; % center of the sphere
cy = 0;
cz = 0;
X = [repmat(cx,1,length(x));x'];
Y = [repmat(cy,1,length(y));y'];
Z = [repmat(cz,1,length(z));z'];
Still thinking how to interpolate the data so you can draw a sphere. See my comments to your question.