I can use the subplot to display multiple images in the same window. for example, I have two images displayed by:
figure,
subFig1=subplot(1,2,1)
surface(rawx,rawy,rawz) % 3D object
subFig2=subplot(1,2,2)
plot(x,z) %profile of the surface.
Assuming rawx, rawy,rawz is the orginal data and x,y,z is measured data. I am using the iteration 'for' to read the measured data.
During the loop, is it possible to hold subFig1 and plot measured profile on top of the surface, and in the mean time, subFig2 can still display the profile in 2D and refresh when the new measurements coming.
I guess this can be done by different handle. However, I can't find any cue so far. please help.
Axes in a subplot behave the same way than in figures. The last subplot called is still active.
In your case, the solution would be:
figure,
subFig1=subplot(1,2,1)
surface(rawx,rawy,rawz)
subFig2=subplot(1,2,2)
hold on
plot(x,z)
for ...
x= ... % your new value
z= ...
plot(x,z) % subplot 122 still active and still hold
end
Related
Quite a simple question but just couldn't find the answer online... I want to visualise a point cloud gathered from a lidar. I can plot the individual frames but wanted to loop them to create a "animation". I know how to do it for normal plots with drawnow but can't get it working with a scatter3. If I simply call scatter3 again like I have done in the commented code then the frame that I am viewing in the scatter plot jumps around with every update (Very uncomfortable). How do i get the scatter3 plot to update to the new points without changing the UI of the scatter ie. Still be able to pan and zoom around the visualised point cloud while it loops through.
EDIT: The file is a rosbag file, I cannot attach it because it is 170MB. The problem doesn't happen when using scatter3 in a loop with a normal array seems to be something with using scatter3 to call a PointCloud2 type file using frame = readMessages(rawBag, i).
EDIT: The problem does not seem to be with the axis limits but rather with the view of the axis within the figure window. When the scatter is initialised it is viewed with the positive x to the right side, positive y out of the screen and positive z upwards, as shown in view 1. Then after a short while it jumps to the second view, where the axis have changed, positive x is now out of the screen, positive y to the right and positive z upwards (both views shown in figures). This makes it not possible to view in a loop as it is constantly switching. So basically how to update the plot without calling scatter3(pointCloudData)?
rawBag = rosbag('jackwalking.bag');
frame = readMessages(rawBag, 1);
scatter3(frame{1});
hold on
for i = 1:length(readMessages(rawBag))
disp(i)
frame = readMessages(rawBag, i);
% UPDATE the 3D Scatter %
% drawnow does not work?
% Currently using:
scatter3(frame{1})
pause(.01)
end
The trick is to not use functions such as scatter or plot in an animation, but instead modify the data in the plot that is already there. These functions always reset axes properties, which is why you see the view reset. When modifying the existing plot, the axes are not affected.
The function scatter3 (as do all plotting functions) returns a handle to the graphics object that renders the plot. In the case of scatter3, this handle has three properties of interest here: XData, YData, and ZData. You can update these properties to change the location of the points:
N = 100;
data = randn(N,3) * 40;
h = scatter3(data(:,1),data(:,2),data(:,3));
for ii = 1:500
data = data + randn(N,3);
set(h,'XData',data(:,1),'YData',data(:,2),'ZData',data(:,3));
drawnow
pause(1/5)
end
The new data can be totally different too, it doesn't even need to contain the same number of points.
But when modifying these three properties, you will see the XLim, YLim and ZLim properties of the axes change. That is, the axes will rescale to accommodate all the data. If you need to prevent this, set the axes' XLimMode, YLimMode and ZLimMode to 'manual':
set(gca,'XLimMode','manual','YLimMode','manual','ZLimMode','manual')
When manually setting the limits, the limit mode is always set to manual.
As far as I understood what you describe as "plots jumpying around", the reason for this are the automatically adjusted x,y,z limits of the scatter3 plot. You can change the XLimMode, YLimMode, ZLimMode behaviour to manual to force the axis to stay fixed. You have to provide initial axes limits, though.
% Mock data, since you haven't provided a data sample
x = randn(200,50);
y = randn(200,50);
z = randn(200,50);
% Plot first frame before loop
HS = scatter3(x(:,1), y(:,1), z(:,1));
hold on
% Provide initial axes limits (adjust to your data)
xlim([-5,5])
ylim([-5,5])
zlim([-5,5])
% Set 'LimModes' to 'manual' to prevent auto resaling of the plot
set(gca, 'XLimMode', 'manual', 'YLimMode', 'manual', 'ZLimMode', 'manual')
for i=2:len(x,2)
scatter3(x(:,i), y(:,i), z(:,i))
pause(1)
end
This yields an "animation" of plots, where you can pan and zoom into the data while continuous points are added in the loop
I'm trying to save a figure with a no-default dimension, but I always obtain the default size plot.
figure
for i=1:6
for j=1:4
subplot(6,4,j+(i-1)*4)
[...]
end
end
w=600; h=800;
set(gcf,'Position',[30 60 w h]);
set(gcf, 'PaperUnits', 'centimeters');
set(gcf,'PaperPositionMode','manual')
print('test','-depsc');
It is mainly a 6-by-4 subplot. I looked for a solution on internet, I found many comments about Position, PaperUnits, PaperPositionMode, but none has worked so far. The only solution that works is when I export as .fig.
What I actually realized, is that after the set(gcf,'Position',[30 60 w h]) the window dimension of the plot is correct, but the subplot are squeezed like when the dimension is the default. If I just insert a pause and manually resize the window (even by almost nothing), the subplots expand nicely within the larger window. But still, with the print command the result is not the desired one.
I tried also with saveas and I got the same result.
Ah, if I manually save the figure, it works perfectly, but, of course, I need to automatize the process!
Thanks for your help!
Although i can't reproduce this behaviour as MATLAB 2014b automatically handles axes resizing, i'll still post an answer, that may need some adjustments.
Basically, what you need to do is :
% Get a handle to your figure object
Myfig=gcf;
% Get all of your figure Children - Warning : if you have a global
% legend in your figure, it will belong to your figure Children and you
% ll have to ignore it
AllChildren=get(Myfig,'Children');
MyAxes=findobj(AllChildren,'type','axes');
% Now you have your axes objects, whose Position attributes should be in
% normalized units. What you need to do now is to store these positions
% before changing the size of your figure, to reapply them after
% resizing (the beauty of normalized positions).
Positions=zeros(size(MyAxes,1),4);
for ii=1:size(MyAxes,1)
Positions(ii,:)=get(MyAxes(ii),'Position');
end
% Resize your figure
w=600;
h=800;
set(gcf,'Position',[30 60 w h]);
% Reuse the positions you stored to resize your subplots
for ii=1:size(MyAxes,1)
set(MyAxes(ii),'Position',Positions(ii,:));
end
This should do the trick.
I have multiple subplots in one figure. The X axis of each plot is the same variable (time). The Y axis on each plot is different (both in what it represents and the magnitude of the data).
I would like a way to zoom in on the time scale on all plots simultaneously. Ideally by using the rectangle zoom tool on one of the plots, and having the other plots change their X limits accordingly. The Y limits should remained unchanged for all of this. Auto fitting the data to fill the plot in the Y direction is acceptable.
(This question is almost identical to Stack Overflow question one Matplotlib/Pyplot: How to zoom subplots together? (except for MATLAB))
Use the built-in linkaxes function as follows:
linkaxes([hAxes1,hAxes2,hAxes3], 'x');
For more advanced linking (not just the x or y axes), use the built-in linkprop function
Use linkaxes as Yair and Amro already suggested. Following is a quick example for your case
ha(1) = subplot(2,1,1); % get the axes handle when you create the subplot
plot([1:10]); % Plot random stuff here as an example
ha(2) = subplot(2,1,2); % get the axes handle when you create the subplot
plot([1:10]+10); % Plot random stuff here as an example
linkaxes(ha, 'x'); % Link all axes in x
You should be able to zoom in all the subplots simultaneously
If there are many subplots, and collecting their axes handle one by one does not seem a clever way to do the job, you can find all the axes handle in the given figure handle by the following commands
figure_handle = figure;
subplot(2,1,1);
plot([1:10]);
subplot(2,1,2);
plot([1:10]+10);
% find all axes handle of type 'axes' and empty tag
all_ha = findobj( figure_handle, 'type', 'axes', 'tag', '' );
linkaxes( all_ha, 'x' );
The first line finds all the objects under figure_handle of type "axes" and empty tag (''). The condition of the empty tag is to exclude the axe handles of legends, whose tag will be legend.
There might be other axes objects in your figure if it's more than just a simple plot. In such case, you need to add more conditions to identify the axes handles of the plots you are interested in.
To link a pair of figures with linkaxes use:
figure;imagesc(data1);
f1h=findobj(gcf,,’type’,’axes’)
figure;imagesc(data2);
f2h=findobj(gcf,,’type’,’axes’)
linkaxes([f1h,f2h],’xy’)
I have two two-by-n arrays, representing 2d-points. These two arrays are plotted in the same figure, but in two different subplots. For every point in one of the arrays, there is a corresponding point i the other array. I want to show this correspondance by drawing a line from one of the subplots to the other subplot.
The solutions i have found are something like:
ah=axes('position',[.2,.2,.6,.6],'visible','off'); % <- select your pos...
line([.1,.9],[.1,.9],'parent',ah,'linewidth',5);
This plots a line in the coordinate system given by the axes call. In order for this to work for me i need a way to change coordinate system between the subplots system and the new system. Anybody know how this can be done?
Maybe there is different way of doing this. If so i would love to know.
First you have to convert axes coordinates to figure coordinates. Then you can use ANNOTATION function to draw lines in the figure.
You can use Data space to figure units conversion (ds2nfu) submission on FileExchange.
Here is a code example:
% two 2x5 arrays with random data
a1 = rand(2,5);
a2 = rand(2,5);
% two subplots
subplot(211)
scatter(a1(1,:),a1(2,:))
% Convert axes coordinates to figure coordinates for 1st axes
[xa1 ya1] = ds2nfu(a1(1,:),a1(2,:));
subplot(212)
scatter(a2(1,:),a2(2,:))
% Convert axes coordinates to figure coordinates for 2nd axes
[xa2 ya2] = ds2nfu(a2(1,:),a2(2,:));
% draw the lines
for k=1:numel(xa1)
annotation('line',[xa1(k) xa2(k)],[ya1(k) ya2(k)],'color','r');
end
Make sure your data arrays are equal in size.
Edit: The code above will do data conversion for a current axes. You can also do it for particular axes:
hAx1 = subplot(211);
% ...
[xa1 ya1] = ds2nfu(hAx1, a1(1,:),a1(2,:));
A simple solution is to use the toolbar in the figure window. Just click "insert" and then "Line".
How do you get rid of the axes and dotted line grids when you plot in Matlab? Also, how do I make subplots of subplots. Since that's probably not very clear, what I mean is the following...
Let's say I have a 10x10x10 .mat file, so I open each of the 10 frames and plot what I have on each 10x10 frame. I generate 2 different plots for each frame so that in total there are 20 plots. For each frame I generate 2 subplots. When I run the code, I get 10 different figures with 10 subplots. I'd like to get for this example 1 figure with 20 subplots where the first two refer to the first iteration, second two refer to the second, etc.
for i = 1:10
z=z(:,:,i);
figure(i)
subplot(1,2,1)
surf(z)
%code, obtain new array...
subplot(1,2,2)
surf(new)
end;
You can hide the axes with
set(gca,'Visible','off')
And if you want 20 subplots, try the following:
for i = 1:10
z=z(:,:,i);
subplot(10,2,2*i-1)
surf(z)
%code, obtain new array...
subplot(10,2,2*i)
surf(new)
end
When you use figure(i), you're referring to Figure i which will be created if it does not exist. And with subplot you can specify the ordering of the subplots with the first two arguments.
Note:
20 subplots on one figure are not going to be pretty --- you probably won't be able to see anything, so you should probably break it up into several figures.