I am attempting to create an animated graph by plotting specific points form 2 column vectors buy am having issues.
I have attempted to use the pause, drawnow, changing my vectors and am still having trouble with my code not working. I have got my vector in a for loop which specifies the points needing to be plotted.
Using ODE45 I have made a column vector with 2 rows.
grid on
func=plot(t,x);
%set(gca,'XLim',[0 tmax])
for i=1:length(x)
set(func,'XData',x(1,i),'YData',x(2,i));
drawnow
end
I expect the output to be an animated graph, but currently, all that I'm getting is either a nonanimated graph, or a bunch of errors saying that I am exceeding the array bounds.
You are using plot with a single point. The default plotting style for plot is to not show individual points, but to connect the input data with lines.
Either change the LineSpec property to e.g. 'o':
func = plot(x(1,1), x(2,1), 'o');
or use the scatter function to plot individual points:
func = scatter(x(1,1), x(2,1));
Related
I am trying to write a MATLAB script to give me a contour map. The contour map must be created from inputs that I generated from 100 images.
The story is like this:
I have 100 images on which I ran an image processing algorithm for optimization. Now, I got their energy curves. So, I have 100 energy curves. I want to create a contour map that will show me where the points are denser on the plot. (the energy curves are plotted as energy vs. iteration with fixed number of iterations)
The following is my variable:
energy(iteration,numImages)
Hope I explained it well.
Thanks in advance.
I interpret your question to boil down to how can I create a surface plot with colors according to the energy found in energy. I would solve this by using the contour function with a grid generated using meshgrid. If each image is described in 1000 data points with 100 files the plot can be generated as follows:
% using stuff as random junk instead of energy
numPoints = 1000;
numFiles = 100;
stuff = rand(1000,100); % replace with actual information
[X, Y] = meshgrid(1:numFiles, 1:numPoints);
contour(X,Y,stuff);
You can also create a 3D surface plot using surf and the same logic.
From what i see of you graph (and using the comments also), one possible way is to use plot3 to plot a line in 3D for every plot.
For doing so, you can use something like this code:
x=(0:0.01:1)';
aexp=zeros(100,numel(x));
hold on
for ii=1:100;
% aexp(ii,:)=exp((-x+ii/10)); %exponential
aexp(ii,:)=exp(-(x-ii/100).^2); %~gaussian
% aexp(ii,:)= x*ii; %linear increase
plot3(x,aexp(ii,:),ii*ones(1,numel(x)));
end
% set(gca,'yscale','log'); % uncomment if you need logscale.
giving
I have a few options of plot. It always plot from the XY view. I changed by hand, but you can use the view command. Notice that i used a simple counter to make the spacing in the z direction.
In a similar manner, you can plot using the contour. For my code, after the data have been generated in the for loop, remove/comment the plot3 and add:
contour(aexp) %outside the for loop,
giving
Notice that i have not really take care what i'm plotting. You can find more info on contour in the Matlab page .
You commented that the x-axis should be number of iterations, y-axis should be energy and z-axis should be the information containing how many lines are passing through from some areas. For this, make a qq variable, being it qq=number_of_lines(number of iterations,energy) . Make a discrete grid for the energy if you don't have one. Number of iterations is probably discrete anyway. The function is you who need to devise, but i would go for something which checks the number of lines for every energy and every iteration. In this case you will have the z-function that depends on y and x, that is the case to use contour or surface.
My function above make a line for every ii point, to have a 3d function. An edition for another extra loop is not hard. Just remember to have the same regular grid for every point, otherwise you will have trouble.
First post here.
I have a bunch of xy data (actually lats and longs), plotted the lines successfully with a scalar value for each line. Scalar values run between 0 and 0.5'ish. Created a colormap and ran it between 0 and 1, based on the native 'autumn' map. I got this far from a couple of other posts, not exactly what I was trying to do but managed to get close using the information provided for others. Issue now is that the relative colorbar that comes up in the plot is all one color??
Here is my script:
figure
% Define colormatrix
cols=flipud(autumn(1001));
% Interpolate the COL matrix to get colors for the data
tcols=interp1(0:0.001:1,cols,probS);
set(gcf,'DefaultAxesColorOrder',tcols);
colormap(tcols);
plot(xx,yy);
caxis([0,1])
c=colorbar;
It tried to attach an image to show what I mean but was denied as a first time user.
The funny thing is, when I run the same script but substitute the xy and the scalar value (probS) for the randomly generated numbers the colorbar behaves, e.g.
close all;clear all
xx=rand(75,25)*10;
yy=rand(75,25)*10;
probS=sort(rand(75,1));
figure
% Define colormatrix
cols=flipud(autumn(1001));
% Interpolate the COL matrix to get colors for the data
tcols=interp1(0:0.001:1,cols,probS);
set(gcf,'DefaultAxesColorOrder',tcols);
colormap(tcols);
plot(xx,yy);
caxis([0,1])
c=colorbar;
any advice or ideas would be most appreciated.
I have some sparse data and want to plot them as markers connected by a smooth, interpolated line - like the default behaviour of Microsoft Excel.
There are solutions to this problem easily found on the internet, but I find them unsatisfactory. What they do is: plot the sparse data as one data set drawing it as markers without lines, interpolate it with a method of choice and plot the interpolation as the second data set, with lines without markers.
The problem with these tricks is that in the legend the two data sets will be listed separately. I would expect a single data set depicted in the legend as a line crossing through a marker.
Is it possible in Matlab?
If you want to plot an interpolated line there are lots of ways to do that. You can try generating an interpolated line using the matlab interp1() function.
Let's create x and y data with no NaN.
x = randn(1,10)
y = randn(1,10)
If you want 1000 data points where previously you only had a few, that's pretty easy:
x2 = min(x):(max(x)-min(x))/1000:max(x)
y2 = interp1(x,y,x2,'cubic')
and you can plot your data and spline using
plot(x,y,'r+')
hold on
plot(x2,y2,'r-')
A custom legend is straightforward when you use handle graphics. You can plot a dummy data set with a red line passing through a marker using
h(1) = plot(NaN,NaN,'r-+')
lstring{1} = 'Data';
You can then add a legend that points to this data set using
legend(h,lstring)
You'll end up with something that looks roughly like this:
The nice thing about using handle graphics (i.e. the h) is you can throw whatever data series you want into the legend as h(end+1) and lstring{end+1}.
I would like to scatter plot different sets of data points. Each point should have a different markerfacecolor, but within a given set, they would all have the same markeredgecolor.
I got this to work by looping over single scatter points individually, because markerfacecolor seems to only be able to take scalar points. The way I do it is that I loop through my data, and look for the appropriate color.
This works fine because I can define each point separately, but it becomes a problem when trying to set up the legend. It tries to list all the different points, but what I'd like is just an empty circle (markerfacecolor white or transparent), with each set having their specific markeredgecolor.
I hope this is clear enough. Thank you.
Mike
I've had luck using patches, setting 'FaceColor', 'EdgeColor' to 'none', 'MarkerEdgeColor' to 'flat' and setting the 'FaceVertexCData' to a Nx3 matrix where each row is a color corresponding the the points specified by you Nx1 'XData', 'YData' and 'ZData'.
h = patch('parent',gca,...
'XData',x,...
'YData',y,...
'ZData',z,...
'FaceColor','none',...
'EdgeColor','none',...
'MarkerFaceColor',faceColor,...
'MarkerEdgeColor','flat',... This is what sets the Edge of each marker
'FaceVertexCData',C) % C is a Nx3
I don't have access to Matlab at the moment, and Octave does not seem to have exactly the same functionality. Check out the Matlab patch properties documentation for more information.
The MATLAB surf plot below is essentially two plots plotted adjacent to each other. For clarity, I have included some code below used to prepare the plot:
band1 = horzcat(band1, eSurface2(:,:,1));
band2 = horzcat(band2, eSurface2(:,:,2));
surf(band2,'DisplayName','band2');
surf(band3,'DisplayName','band2');
I would like for the y axis numbering to restart at the start of the second graph. How do I go about doing that?
You can use the 'YTick' and 'YTickLabel' properties of the axis to control the ticks, this way you can make it start from zero for the second graph. It will require some trail and error to get it right. See the relevant doc here (you'll have to scroll all the way to the bottom of the page).
Take advantage of the following feature of 'YTickLabel': "If you do not specify enough text labels for all the tick marks, MATLAB uses all of the labels specified, then reuses the specified labels".