When I call this function, the axes are moving with the plot. How can I stop this from happening? I tried putting xlim and ylim before the function in the command window but that didn't work.
My code is:
function h = plootwithanimation(x,y)
for h = 1:length(x)
plot(x(h),y(h),'*')
pause(1)
hold on
end
Try fixing the bounds using the axis function:
function h = plootwithanimation(x,y)
for h = 1:length(x)
plot(x(h),y(h),'*')
axis([0 10 -2 100]) %or whatever you want. This sets 0<x<10 and -2<y<100
pause(1)
hold on
end
You can fix the bounds by using xlim and ylim as you tried, but plotting will ignore whatever you set the axes to before calling plot.
You should instead use them after the plot
function h = plotwithanimation(x, y, xlims, ylims)
% Also pass in axis limits
% xlims = [x0,x1]
% ylims = [y0,y1]
hold on; % You only have to hold on once around plotting
for h = 1:length(x)
plot(x(h),y(h),'*');
xlim(xlims);
ylim(ylims);
pause(1);
end
hold off; % Good habit so you don't accidentally plot over this figure later
Related
When I use ginput to mark tqo points it is followed by updating the axes scales. How can I stop the "auto-scaling" of the axes in Matlab?
Code:
clc;
clear all;
close all;
grid on;
message = sprintf('Select two points for a line.');
uiwait(helpdlg(message));
[x, y] = ginput(2);
Xorigin1 = x(1);
Xorigin2 = x(2);
Yorigin1 = y(1);
Yorigin2 = y(2);
plot([Xorigin1,Xorigin2],[Yorigin1,Yorigin2], 'b-', 'LineWidth',2);
hold on;
plot([Xorigin1,Xorigin2],[Yorigin1,Yorigin2], 'r+', 'LineWidth',2,'MarkerSize', 12);
Both the x- and y-axis are by default set to automically rescale their limits whenever data in the figure is changed.
You can overwrite this using
xlim manual
ylim manual
I have the following figure
that I created using the following code
%% figures
DateNumObs=datenum(table2array(ADCPCRUM2(1:1678,ColumnYear)),table2array(ADCPCRUM2(1:1678,ColumnMonth)),table2array(ADCPCRUM2(1:1678,ColumnDay)),table2array(ADCPCRUM2(1:1678,ColumnHour)),table2array(ADCPCRUM2(1:1678,ColumnMinutes)),table2array(ADCPCRUM2(1:1678,ColumnSeconds)));
Flipecart=permute(ecart(1:1677,:),[2,1]);
Flipecartreel=permute(ecartreel(1:1677,:),[2,1]);
bottomVel=min(min(min(Magnitude)),min(min(velocityModel*1000)));
topVel=max(max(max(Magnitude)),max(max(velocityModel*1000)));
bottomVer=min(min(Flipecart))
topVer=max(max(Flipecart))
figure
subplot(4,1,1);
FlipMag=permute(Magnitude,[2,1]);
[C,h] =contourf(DateNumObs,1:1:22,FlipMag);
datetick('x','dd/mm/yy','keeplimits','keepticks')
caxis manual
caxis([bottomVel topVel])
c=colorbar;
c.Label.String = 'Horizontal velocity(mm/s)';
xlabel('Date');
ylabel('Depth(m from bottom)');
set(h,'LineColor','none')
title('Observation');
subplot(4,1,2);
[C,h] =contourf(DateNumObs(1:1677),1:1:22,MagMatrixH1*1000);
datetick('x','dd/mm/yy','keeplimits','keepticks')
caxis manual
caxis([bottomVel topVel])
c=colorbar;
c.Label.String = 'Horizontal velocity(mm/s)';
xlabel('Date');
ylabel('Depth(m from bottom)');
set(h,'LineColor','none')
title('Model D1');
subplot(4,1,3)
% x0=10;
% y0=10;
% width=550;
% height=400
gcf=plot(DateNumObs(1:1677),Flipecart(10,:))
% set(gcf,'LineWidth',1,'position',[x0,y0,width,height]) % Part giving the error
datetick('x','dd/mm/yy','keeplimits','keepticks')
caxis manual
caxis([bottomVer topVer])
subplot(4,1,4)
c=colorbar;
plot(DateNumObs(1:1677),Flipecartreel(10,:))
datetick('x','dd/mm/yy','keeplimits','keepticks')
caxis manual
caxis([bottomVer topVer])
I am trying to got the normal plot to be the same size as the (blue) contourf plots by using the code which is commented in the code I posted. I got this code from https://nl.mathworks.com/matlabcentral/answers/65402-how-to-set-graph-size .
However, when I try to run it it gives me the following error:
Error using matlab.graphics.chart.primitive.Line/set
There is no position property on the Line class.
Error in StatisticsSOLA (line 315)
set(gcf,'LineWidth',1,'position',[x0,y0,width,height])
I also tried is it possible to change the height of a subplot? but I get the same error. How do I prevent this error and change the width of the bottom two figures?
You are trying to set the position of the axes and the linewidth of the line object in one go, but are not providing the correct handles. Furthermore, don't store the handles of the lines in gcf, since this is a reference to the currently active figure.
Instead you can do:
data = rand(100,200); % some data
fig = figure(1); clf;
% first subplot with colorbar
ax(1) = subplot(211);
imagesc(data)
c = colorbar;
% second subplot without colorbar
ax(2) = subplot(212);
p = plot(data(1,:))
% set height and width of second subplot
drawnow % needed to get right position value of ax(1) and ax(2)
ax_pos = [ax(2).Position(1:2) ax(1).Position(3:4)]; % keep ax(2)'s left and bottom position, and set same width and height as ax(1)
set(ax(2), 'Position', ax_pos)
Alternative
Sometimes it is easier to create colorbar in the second axes, and hide it. This way you don't have to set the positions of the axes yourself.
data = rand(100,200); % some data
fig = figure(1); clf;
% first subplot with colorbar
ax(1) = subplot(211);
imagesc(data)
c = colorbar;
% second subplot without colorbar
ax(2) = subplot(212);
p = plot(data(1,:))
c = colorbar; % draw useless colorbar,
c.Visible = 'off'; % and hide it
Figure should look the same:
I'm trying to create an animated plot but my code is very slow, perhaps the method I'm using is too naive. In the below example, I have 4 subplots each with 3 lines, which I update in a 'time' loop.
clc;clear;close all;
state = {'$x-Position$','$x-Velocity$','$y-Position$','$y-Velocity$'};
ylabels = {'$x$','$\dot{x}$','$y$','$\dot{y}$'};
options1 = {'interpreter','latex'};
options2 = {'interpreter','latex','fontsize',20};
maxT = 300;
for pp = 1:4
hh1(pp)=subplot(2,2,pp);
xlabel('$t$',options2{:});
ylabel(ylabels{pp},options2{:});
title(state{pp},options1{:})
xlim([0 maxT])
hold on
end
x = randn(4,300);
z = randn(4,300);
x_est = randn(4,300);
for k = 2:maxT
for p = 1:4
plot(hh1(p),k-1:k,x(p,k-1:k),'b','linewidth',2)
plot(hh1(p),k-1:k,z(p,k-1:k),'m')
plot(hh1(p),k-1:k,x_est(p,k-1:k),':k','linewidth',2)
end
drawnow;
end
As can be seen from the profiler output, the drawnow is killing the time. Is there any way I can be more efficient in creating this animation?
Because you want an animation, there is no alternative to using drawnow to update the frame. However, it's not drawnow in particular which is slowing you down - the profiler can be misleading... drawnow simply updates all of the graphics changes since the last re-draw, which in your case is a dozen new plots!
You'll find that hold is pretty slowing. For instance if you're wiser about your holding, remove the existing hold on and only hold when actually plotting
% ... above code the same but without 'hold on'
for p = 1:4
hold(hh1(p), 'on');
% plots
hold(hh1(p), 'off');
end
This saves ~10% time on my PC (12.3sec down to 11.3sec).
The real speed up comes from removing hold entirely, along with all of the individual plot calls! This method also doesn't touch the line formatting which will help with speed. See a previous question about updating plot data here.
Simply update the plot data instead of adding plots. This gives me a speedup of ~68% (12.3sec down to 4.0sec).
% ... your same setup
% Initialise plot data
x = randn(4,300);
z = randn(4,300);
x_est = randn(4,300);
plts = cell(4,3);
hh1 = cell(4,1);
% Loop over subplots and initialise plot lines
for p = 1:4
hh1{p}=subplot(2,2,p);
xlabel('$t$',options2{:});
ylabel(ylabels{p},options2{:});
title(state{p},options1{:})
xlim([0 maxT])
% Hold on to make 3 plots. Create initial points and set line styles.
% Store the plots in a cell array for later reference.
hold on
plts{p,1} = plot(hh1{p},1:2,x(p,1:2),'b','linewidth',2);
plts{p,2} = plot(hh1{p},1:2,z(p,1:2),'m');
plts{p,3} = plot(hh1{p},1:2,x_est(p,1:2),':k','linewidth',2);
hold off
end
% March through time. No replotting required, just update XData and YData
for k = 2:maxT
for p = 1:4
set(plts{p,1}, 'XData', 1:k, 'YData', x(p,1:k) );
set(plts{p,2}, 'XData', 1:k, 'YData', z(p,1:k) );
set(plts{p,3}, 'XData', 1:k, 'YData', x_est(p,1:k) );
end
drawnow;
end
Now the plotting is pretty optimised. If you want the animation to be even quicker then just plot every 2nd, 3rd, ..., nth timestep instead of every timestep by using for k = 2:n:maxT.
I'm trying to limit x axis, i.e., frequency axis to 4 Hz in MatLab. This is the code I used:
subplot(3,1,2);
%Fse = 220;
time = 0:1/fse:secBuffer-1/fse;
%a = eegCounter;
c = eegBuffer;
wo = 50 / (1000/2);
bw = wo / 60;
[b,a] = iirnotch(wo,bw);
y = filter(b,a,c);
ydft = fft(c);
xdft = fft(y);
xlabel('Frequency');
ylabel('Signal');
xlim([1,4]);
ylim([1,4]);
plot(xdft,ydft);
However mine is live signal plotting and both x axis and y axis keep changing according to incoming packets. How to limit x axis to 4 Hz?
When plotting MATLAB automatically tries to fit the axis with the dynamic range of the data. Therefore if you want to make sure only a given range is plotted, you need to specify it AFTER the call to plot to force MATLAB to do it, otherwise it won't and you will be stuck with the whole data.
Here is a very simple code in which I call xlim either before or after the call to plot. See the difference?
clear
clc
close all
x = 1:50;
y = x.^2;
figure
subplot(1,2,1)
xlim([1 20])
plot(x,y)
title('xlim before call to plot')
subplot(1,2,2)
plot(x,y)
xlim([1 20])
title('xlim after call to plot')
Produces this:
You have to set the XLimMode (and YLimMode) properties of the axes to manual. But even if you do so every call to plot(...) will reset that to auto and mess up your axes limits.
The cleanest way is to first define your axes and your plots outside of any loop (not forgetting to get their handle), then when you update the data just update the XData and YData of the line objects, using the set method. The set method will only update the property you pass in parameters, so it will not modify the XLimMode property.
%// This part of the code should run only once
h.ax = subplot(3,1,2) ; %// get the handle of the axes
h.line = plot(0) ; %// create an empty line plot
set(h.ax , 'XLimMode','manual' , 'XLim',[1 4]) ; %// define the properties of the axes (X)
set(h.ax , 'YLimMode','manual' , 'YLim',[1 4]) ; %// define the properties of the axes (Y)
xlabel('Frequency');
ylabel('Signal');
%//
%// This part of the code is the loop where you calculate and update your plot
%// ...
%// now do your calculations
%// ...
%// when it is time to update, just call:
set( h.line, 'XData',xdft 'YData',ydft ) ;
You can use the function axis as defined there axis function matlab
How to plot something outside the axis with MATLAB? I had like to plot something similar to this figure;
Thank you.
Here is one possible trick by using two axes:
%# plot data as usual
x = randn(1000,1);
[count bin] = hist(x,50);
figure, bar(bin,count,'hist')
hAx1 = gca;
%# create a second axis as copy of first (without its content),
%# reduce its size, and set limits accordingly
hAx2 = copyobj(hAx1,gcf);
set(hAx2, 'Position',get(hAx1,'Position').*[1 1 1 0.9], ...
'XLimMode','manual', 'YLimMode','manual', ...
'YLim',get(hAx1,'YLim').*[1 0.9])
delete(get(hAx2,'Children'))
%# hide first axis, and adjust Z-order
axis(hAx1,'off')
uistack(hAx1,'top')
%# add title and labels
title(hAx2,'Title')
xlabel(hAx2, 'Frequency'), ylabel(hAx2, 'Mag')
and here is the plot before and after:
You can display one axis with the scale you want, then plot your data on another axis which is invisible and large enough to hold the data you need:
f = figure;
% some fake data
x = 0:20;
y = 23-x;
a_max = 20;
b_max = 23;
a_height = .7;
%% axes you'll see
a = axes('Position', [.1 .1 .8 a_height]);
xlim([0 20]);
ylim([0 20]);
%% axes you'll use
scale = b_max/a_max;
a2 = axes('Position', [.1 .1 .8 scale*a_height]);
p = plot(x, y);
xlim([0 20]);
ylim([0 b_max]);
set(a2, 'Color', 'none', 'Visible', 'off');
I had similar problem and I've solved it thanks to this answer. In case of bar series the code is as follows:
[a,b] = hist(randn(1000,1)); % generate random data and histogram
h = bar(b,a); % plot bar series
ylim([0 70]) % set limits
set(get(h,'children'),'clipping','off')% turn off clippings