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I find that data points that lie on or near the axes are difficult to see. The obvious fix, of course, is to simply change the plot area using axis([xmin xmax ymin ymax]), but this is not preferable in all cases; for example, if the x axis is time, then moving the minimum x value to -1 to show activity at 0 does not make sense.
Instead, I was hoping to simply move the x and y axes away from the plot area, like I have done here:
left: MATLAB generated, right: desired (image editing software)
Is there a way to automatically do this in MATLAB? I thought there might be a way to do it by using the outerposition axes property (i.e., set it to [0 0 0.9 0.9] and drawing new axes where they originally were?), but I didn't get anywhere with that strategy.
The answers here already show you most of the way - here is the last step to separate the x and y axle as per the example you put together.
f = figure ( 'color', 'white' );
% create the axes and set some properties
ax = axes ( 'parent', f, 'box', 'off', 'nextplot', 'add', 'XMinorTick', 'on', 'YMinorTick', 'on' );
% plot some data
plot ( ax, 0:10, [0:10].^2, 'rx-' )
% modify the x and y limits to below the data (by a small amount)
ax.XLim(1) = ax.XLim(1)-(ax.XTick(2)-ax.XTick(1))/4;
ax.YLim(1) = ax.YLim(1)-(ax.YTick(2)-ax.YTick(1))/4;
% Set the tick direction
ax.TickDir = 'out';
% draw the plot to generate the undocumented vertex data var
drawnow()
%% R2015a
% X, Y and Z row of the start and end of the individual axle.
ax.XRuler.Axle.VertexData(1,1) = 0;
ax.YRuler.Axle.VertexData(2,1) = 0;
%% R2015b
% extract the x axis vertext data
% X, Y and Z row of the start and end of the individual axle.
vd = get(ax.XAxis.Axle,'VertexData');
% reset the zero value
vd(1,1) = 0;
% Update the vertex data
set(ax.XAxis.Axle,'VertexData',vd);
% repeat for Y (set 2nd row)
vd = get(ax.YAxis.Axle,'VertexData');
vd(2,1) = 0;
set(ax.YAxis.Axle,'VertexData',vd);
Edit: The vertex is something that Matlab recreates whenever the axes/figure changes size or if you zoom or pan for example.
You can try to counteract this (remember you are using undocumented features here) by adding a listener to attempt to capture this. We can use the MarkedClean event which is called quite a lot of times.
addlistener ( ax, 'MarkedClean', #(obj,event)resetVertex(ax) );
Where you resetVertex function is something like: (R2015b shown only)
Edit 2 added the code to turn off the minor ticks below 0.
function resetVertex ( ax )
% extract the x axis vertext data
% X, Y and Z row of the start and end of the individual axle.
ax.XAxis.Axle.VertexData(1,1) = 0;
% repeat for Y (set 2nd row)
ax.YAxis.Axle.VertexData(2,1) = 0;
% You can modify the minor Tick values by modifying the vertex data
% for them, e.g. remove any minor ticks below 0
ax.XAxis.MinorTickChild.VertexData(:,ax.XAxis.MinorTickChild.VertexData(1,:)<0) = [];
ax.YAxis.MinorTickChild.VertexData(:,ax.YAxis.MinorTickChild.VertexData(2,:)<0) = [];
end
Note: this uses undocumented features -> so may only work in certain versions of Matlab (I have added the code for r2015a & r2015b) and Matlab may recreate the vertex data depending on what you do with the plots..
Here is a simple way for achieving that:
% some data:
x = 1:100;
f=#(x) 5.*x;
y=f(x)+rand(1,length(x))*50;
close all
% plotting:
f1 = figure('Color','white');
ax = axes;
plot(ax,x,y,'o');
% 'clean' the data area a little bit:
box off
ax.TickDir = 'out';
% pushing the axis a bit forward:
lims = axis;
pos = ax.Position;
axis([lims(1)-ax.XTick(2)/5 lims(2)+0.1 lims(3)-ax.YTick(2)/5 lims(4)+0.1])
% Create lines
firstXtick = 0.013; %this value need to be adjusted only once per figure
firstYtick = 0.023; %this value need to be adjusted only once per figure
lx = annotation(f1,'line',[pos(1) pos(1)+firstXtick],...
[pos(2) pos(2)],'Color',[1 1 1],'LineWidth',1);
ly = annotation(f1,'line',[pos(1) pos(1)],...
[pos(2) pos(2)+firstYtick],'Color',[1 1 1],'LineWidth',1);
Which yields this figure:
The only thing to adjust here, once per type of figure, is firstXtick and firstYtick values, that have to be fine tuned to the specific axis. After setting them to the correct value the figure can be resized with no problem. Zoom and pan require a little fixes.
You can start your axes from less than zero and then remove the less than zero ticks from your plot. e.g.
plot(0:3:30,0:3:30); %Some random data for plotting
h = gca;
axis([-1 30 -1 30]); %Setting the axis from less than zero
box off; %Removing box
h.TickDir = 'out'; %Setting Direction of ticks to outwards
h.XTickLabel(1)= {' '}; %Removing the first tick of X-axis
h.YTickLabel(1)= {' '}; %Removing the first tick of Y-axis
With this code, you'll get this result:
This may have a drawback, sometimes, that zero ticks may also get removed (as you can see in above figure). This is because the plot had set the first ticks of axes equal to zero. This can be avoided using if condition. So, the code can be modified as below:
plot(0:3:30,0:3:30);
h = gca;
axis([-1 30 -1 30]);
box off;
h.TickDir = 'out';
if str2num(cell2mat(h.XTickLabel(1))) <0
h.XTickLabel(1)= {' '};
end
if str2num(cell2mat(h.YTickLabel(1))) <0
h.YTickLabel(1)= {' '};
end
The above code will yield the following result:-
Also note that, for your case, since your axes ticks are very less, -1 may not be much suitable for the starting value of axes and you may need to use -0.1 instead i.e. axis([-0.1 30 -0.1 30]);
With a slight modification of #matlabgui's answer you can track the (major) tick limits:
ax = gca();
% Set the tick direction
ax.TickDir = 'out';
% Make sure this stays when saving, zooming, etc
addlistener ( ax, 'MarkedClean', #(obj,event) change_ticks(ax) );
% Draw the plot to generate the undocumented vertex data variable
% and call callback for the first time
drawnow();
The callback
function change_ticks( ax )
% Modify ruler
ax.XRuler.Axle.VertexData(1,1) = ax.XTick(1);
ax.XRuler.Axle.VertexData(1,2) = ax.XTick(end);
ax.YRuler.Axle.VertexData(2,1) = ax.YTick(1);
ax.YRuler.Axle.VertexData(2,2) = ax.YTick(end);
end
I haven't test extensively but seems to work for custom ticks too. This nicely cuts the rulers not only on zero but beyond the fist and last tick. This was tested in Matlab 2019a on Windows and ax.XRuler.Axle.VertexData works just fine. Note this is only for major ticks!
I need to make a plot with a discrete colorbar in Matlab. I do this in the following way:
data = randi(10, 20);
imagesc(data)
my_colormap = rand(10, 3);
colormap(my_colormap)
cb = colorbar
set(cb,'YTickLabel',{'A';'B';'C';'D';'E';'F';'G';'H';'I';'J';})
Now my problem is that the colorbar tick labels and the small lines in the colorbar don't align nicely. How can I even the colorbar tick labels and the small lines better as illustrated in the following pic:
The TickLabel on the colorbar each correspond to a value (a Tick). To place the TickLabels in the middle, you need to place the tick in the middle. To make this dynamic (so that It does not change when resizing the image) was I bit tricky I recall and I do not really recall. To set the ticks just once is not so hard though,
set(hCbar,'YTicks',RightYTicks);
EDIT:
On request I will post an example. This should give a hint of what to do.
x = 1:10;
y = 1:10;
cmap = jet(10);
[x, y] = meshgrid(x,y); %x and y grid
c = x-0.1; %Set color code to increase to the right
hFig = figure;
scatter(x(:),y(:),10,c(:),'filled'); % Simpler for the example
set(gca(hFig),'CLim',[0,10]);
colormap(cmap);
hCbar = colorbar;
set(hCbar,'YTicks',0.5:9.5);
set(hCbar,'YTickLabels',{'A','B','C','D','E','F','G','H','I','J'});
For newer matlab version, the YTicks may have changed name to Ticks And YTickLabels may be called TickLabels.
I would like to plot two graphs with the same x-axis but with different y-axies, one stacked above the other. There is a similar question asked below BUT it doesn't account for changes of dimensions in the y-axes. I have edited this code to do so but hope there would be a more elegant approach (maybe using a "hold on" type code).
How to plot graphs above each other in Matlab?
Here is some code which might do what you want...if I understood right. Basically you create 2 different axes in the same figure, one on top of the other, and you play around with XTick and YTick. You can start from this I guess.:
clear
close all
clc
x = 1:10;
y1 = -(x.^2);
y2 = sin(x);
figure('Units','Normalized');
hAxes1 = axes('Position',[0.1 0.1 .8 .4]);
yLim = get(hAxes1,'YLim');
Axes1Position = get(hAxes1,'Position');
NewAxesPosition = [Axes1Position(1) Axes1Position(2)+0.4 Axes1Position(3) Axes1Position(4)];
hAxes2 = axes('Position',NewAxesPosition);
plot(x,y1,'b','Parent',hAxes1);
TICK = get(hAxes1,'YTick')
set(hAxes1,'XTick',2:1:10,'YTick',TICK(1:end-1))
hold on
plot(x,y2,'r','parent',hAxes2)
set(gca,'XTick',[],'XTickLabel',[])
hold off
Giving this:
This is not optimal but due to lack of time I have to stop here :) Of course you can alter the display of the axis or the tick marks as you wish. Moreover you could use text annotations to customize the YTicks even more nicely.Hope that helps!
Example:
A = 1000;
a = 0.005;
b = 0.005;
t = 0:900;
z1 = A*exp(-a*t);
z2 = sin(b*t);
[ax,p1,p2] = plotyy(t,z1,t,z2,'semilogy','plot');
ylabel(ax(1),'Semilog Plot') % label left y-axis
ylabel(ax(2),'Linear Plot') % label right y-axis
xlabel(ax(2),'Time') % label x-axis
With reference to: http://www.mathworks.com/help/matlab/creating_plots/plotting-with-two-y-axes.html
I'm trying to find a way to nicely plot my measurement data of digital signals.
So I have my data available as csv and mat file, exported from an Agilent Oscilloscope. The reason I'm not just taking a screen shot of the Oscilloscope screen is that I need to be more flexible (make several plots with one set of data, only showing some of the lines). Also I need to be able to change the plot in a month or two so my only option is creating a plot from the data with a computer.
What I'm trying to achieve is something similar to this picture:
The only thing missing on that pic is a yaxis with 0 and 1 lines.
My first try was to make a similar plot with Matlab. Here's what I got:
What's definitely missing is that the signal names are right next to the actual line and also 0 and 1 ticks on the y-axis.
I'm not even sure if Matlab is the right tool for this and I hope you guys can give me some hints/a solution on how to make my plots :-)
Here's my Matlab code:
clear;
close all;
clc;
MD.RAW = load('Daten/UVLOT1 debounced 0.mat'); % get MeasurementData
MD.N(1) = {'INIT\_DONE'};
MD.N(2) = {'CONF\_DONE'};
MD.N(3) = {'NSDN'};
MD.N(4) = {'NRST'};
MD.N(5) = {'1V2GD'};
MD.N(6) = {'2V5GD'};
MD.N(7) = {'3V3GD'};
MD.N(8) = {'5VGD'};
MD.N(9) = {'NERR'};
MD.N(10) = {'PGD'};
MD.N(11) = {'FGD'};
MD.N(12) = {'IGAGD'};
MD.N(13) = {'GT1'};
MD.N(14) = {'NERRA'};
MD.N(15) = {'GT1D'};
MD.N(16) = {'GB1D'};
% concat vectors into one matrix
MD.D = [MD.RAW.Trace_D0, MD.RAW.Trace_D1(:,2), MD.RAW.Trace_D2(:,2), MD.RAW.Trace_D3(:,2), ...
MD.RAW.Trace_D4(:,2), MD.RAW.Trace_D5(:,2), MD.RAW.Trace_D6(:,2), MD.RAW.Trace_D7(:,2), ...
MD.RAW.Trace_D8(:,2), MD.RAW.Trace_D9(:,2), MD.RAW.Trace_D10(:,2), MD.RAW.Trace_D11(:,2), ...
MD.RAW.Trace_D12(:,2), MD.RAW.Trace_D13(:,2), MD.RAW.Trace_D14(:,2), MD.RAW.Trace_D15(:,2)];
cm = hsv(size(MD.D,2)); % make colormap for plot
figure;
hold on;
% change timebase to ns
MD.D(:,1) = MD.D(:,1) * 1e9;
% plot lines
for i=2:1:size(MD.D,2)
plot(MD.D(:,1), MD.D(:,i)+(i-2)*1.5, 'color', cm(i-1,:));
end
hold off;
legend(MD.N, 'Location', 'EastOutside');
xlabel('Zeit [ns]'); % x axis label
title('Messwerte'); % title
set(gca, 'ytick', []); % hide y axis
Thank you guys for your help!
Dan
EDIT:
Here's a pic what I basically want. I added the signal names via text now the only thing that's missing are the 0, 1 ticks. They are correct for the init done signal. Now I just need them repeated instead of the other numbers on the y axis (sorry, kinda hard to explain :-)
So as written in my comment to the question. For appending Names to each signal I would recommend searching the documentation of how to append text to graph. There you get many different ways how to do it. You can change the position (above, below) and the exact point of data. As an example you could use:
text(x_data, y_data, Var_Name,'VerticalAlignment','top');
Here (x_data, y_data) is the data point where you want to append the text and Var_Name is the name you want to append.
For the second question of how to get a y-data which contains 0 and 1 values for each signal. I would do it by creating your signal the way, that your first signal has values of 0 and 1. The next signal is drawn about 2 higher. Thus it changes from 2 to 3 and so on. That way when you turn on y-axis (grid on) you get values at each integer (obviously you can change that to other values if you prefer less distance between 2 signals). Then you can relabel the y-axis using the documentation of axes (check the last part, because the documentation is quite long) and the set() function:
set(gca, 'YTick',0:1:last_entry, 'YTickLabel',new_y_label(0:1:last_entry))
Here last_entry is 2*No_Signals-1 and new_y_label is an array which is constructed of 0,1,0,1,0,....
For viewing y axis, you can turn the grid('on') option. However, you cannot chage the way the legends appear unless you resize it in the matlab figure. If you really want you can insert separate textboxes below each of the signal plots by using the insert ->Textbox option and then change the property (linestyle) of the textbox to none to get the exact same plot as above.
This is the end result and all my code, in case anybody else wants to use the good old ctrl-v ;-)
Code:
clear;
close all;
clc;
MD.RAW = load('Daten/UVLOT1 debounced 0.mat'); % get MeasurementData
MD.N(1) = {'INIT\_DONE'};
MD.N(2) = {'CONF\_DONE'};
MD.N(3) = {'NSDN'};
MD.N(4) = {'NRST'};
MD.N(5) = {'1V2GD'};
MD.N(6) = {'2V5GD'};
MD.N(7) = {'3V3GD'};
MD.N(8) = {'5VGD'};
MD.N(9) = {'NERR'};
MD.N(10) = {'PGD'};
MD.N(11) = {'FGD'};
MD.N(12) = {'IGAGD'};
MD.N(13) = {'GT1'};
MD.N(14) = {'NERRA'};
MD.N(15) = {'GT1D'};
MD.N(16) = {'GB1D'};
% concat vectors into one matrix
MD.D = [MD.RAW.Trace_D0, MD.RAW.Trace_D1(:,2), MD.RAW.Trace_D2(:,2), MD.RAW.Trace_D3(:,2), ...
MD.RAW.Trace_D4(:,2), MD.RAW.Trace_D5(:,2), MD.RAW.Trace_D6(:,2), MD.RAW.Trace_D7(:,2), ...
MD.RAW.Trace_D8(:,2), MD.RAW.Trace_D9(:,2), MD.RAW.Trace_D10(:,2), MD.RAW.Trace_D11(:,2), ...
MD.RAW.Trace_D12(:,2), MD.RAW.Trace_D13(:,2), MD.RAW.Trace_D14(:,2), MD.RAW.Trace_D15(:,2)];
cm = hsv(size(MD.D,2)); % make colormap for plot
figure;
hold on;
% change timebase to ns
MD.D(:,1) = MD.D(:,1) * 1e9;
% plot lines
for i=2:1:size(MD.D,2)
plot(MD.D(:,1), MD.D(:,i)+(i-2)*2, 'color', cm(i-1,:));
text(MD.D(2,1), (i-2)*2+.5, MD.N(i-1));
end
hold off;
%legend(MD.N, 'Location', 'EastOutside');
xlabel('Zeit [ns]'); % x axis label
title('Messwerte'); % title
% make y axis and grid the way I want it
set(gca, 'ytick', 0:size(MD.D,2)*2-3);
grid off;
set(gca,'ygrid','on');
set(gca, 'YTickLabel', {'0'; '1'});
ylim([-1,(size(MD.D,2)-1)*2]);
I would like to change the default arrow head style in quiver plot. How can I change it?
For Matlab Version > R2014b
Since R2014b version, Matlab has modified the structure of its graphical components. Here is the up-to-date code that uses Matlab's annotations.
is produced by
headWidth = 8;
headLength = 8;
LineLength = 0.08;
%some data
[x,y] = meshgrid(0:0.2:2,0:0.2:2);
u = cos(x).*y;
v = sin(x).*y;
%quiver plots
figure('Position',[10 10 1000 600],'Color','w');
hax_1 = subplot(1,2,1);
hq = quiver(x,y,u,v); %get the handle of quiver
title('Regular Quiver plot','FontSize',16);
%get the data from regular quiver
U = hq.UData;
V = hq.VData;
X = hq.XData;
Y = hq.YData;
%right version (with annotation)
hax_2 = subplot(1,2,2);
%hold on;
for ii = 1:length(X)
for ij = 1:length(X)
headWidth = 5;
ah = annotation('arrow',...
'headStyle','cback1','HeadLength',headLength,'HeadWidth',headWidth);
set(ah,'parent',gca);
set(ah,'position',[X(ii,ij) Y(ii,ij) LineLength*U(ii,ij) LineLength*V(ii,ij)]);
end
end
%axis off;
title('Quiver - annotations ','FontSize',16);
linkaxes([hax_1 hax_2],'xy');
Please note that this piece of code changes the head style and controls for the length of the line (in the left panel, you can see that arrows overlap on the upper-left part of the left subplot, while it does not on the right subplot). The length and width of the arrow heads are not modified.
For this edit, I didn't keep the colors scheme that coded for the angle, and discarded the dynamic head size. It makes things clearer.
For Matlab Version < R2014b
Quiver plots are hard to modify. As #Luis Mendo said, you can modify the quiver function within the matlab install. However, you will still be limited by the complexity of programmatically drawing arrows with nice patches/lines. There might be an easier route using annotation - see the "Quiver - annotation" subplot that sets the headStyle property to cback1.
Annotations are graphical objects (lines, textboxes, arrows, ...) that you can be easily inserted by hand once a plot is done. They display additional text or point to a particular area for example. You can also insert them programmatically by defining their positions - and that's the option we will take. We first draw a regular quiver plot (left panel), get the blue lines' X and Y data, and use these coordinates to insert annotation arrows, each of them being displayed at the exact same location (same position, same angle, same size; right panel).
Annotation arrows have some nice properties you can easily modify, such as Color, HeadWidth, HeadLength, and HeadStyle. In the following plot, I modified each arrow's color depending on its angle against the x-axis, and headWidth that depends length.
The following picture
is produced by
%some data
[x,y] = meshgrid(0:0.2:2,0:0.2:2);
u = cos(x).*y;
v = sin(x).*y;
%quiver plots
figure('Position',[10 10 1000 600],'Color','w');
hax_1 = subplot(1,2,1);
%left version (regular)
hq1 = quiver(x,y,u,v);
%get the line position (first handle)
hkid = get(hq1,'children');
X = get(hkid(1),'XData');
Y = get(hkid(1),'YData');
axis off;
title('Quiver - regular ','FontSize',16);
%right version (with annotation)
hax_2 = subplot(1,2,2);
cmap = jet(116); %colormap, 116 because angles goes up to 115 degrees
for ii = 1:3:length(X)-1
headWidth = 200 * sqrt((X(ii+1)-X(ii)).^2 + (Y(ii+1)-Y(ii)).^2); % set the headWidth, function of length of arrow
angled = floor(atan2(Y(ii+1)-Y(ii),X(ii+1)-X(ii))*180/pi) + 1; %get the angle
ah = annotation('arrow',...
'Color', cmap(angled,:),...
'headStyle','cback1','HeadLength',50,'HeadWidth',headWidth);
set(ah,'parent',gca);
set(ah,'position',[X(ii) Y(ii) X(ii+1)-X(ii) Y(ii+1)-Y(ii)]);
end
axis off;
title('Quiver - annotations ','FontSize',16);
linkaxes([hax_1 hax_2],'xy');
The file refresh.m located in folder ...\MATLAB\...\toolbox\matlab\specgraph\#specgraph\#quivergroup\#quivergroup contains the following lines:
%// Arrow head parameters
alpha = .33; %// Size of arrow head relative to the length of the vector
beta = .25; %// Width of the base of the arrow head relative to the length
Changing the values of alpha and beta achieves the desired effect.
However, this entails modifying Matlab's files, and thus it's not recommended. If you do it, keep a copy of the original refresh.m file.
Results using the example code that appears in quiver's help:
[x,y] = meshgrid(-2:.2:2,-1:.15:1);
z = x .* exp(-x.^2 - y.^2); [px,py] = gradient(z,.2,.15);
quiver(x,y,px,py), hold off, axis image
With original parameters (alpha = .33; beta = .25;):
With alpha = .5; beta = .5;:
You can start here:
http://www.mathworks.com/help/matlab/ref/quiver.html
and then you can look for the available properties of quiver here:
http://www.mathworks.com/help/matlab/ref/quivergroupproperties.html
For example, the property MaxHeadSize allows to change the size of the arrow-heads.
EDIT: More information in this link: Arrow properties
Read at bottom, where says
You can select an annotation and then choose Show M-code to obtain a
code snippet that you can insert in a function or script to reproduce
the annotation.
This answer of pablo1977 was the most instructive for me. I managed to get bigger arrow heads by adjusting the quiver group properties, namely by these 2 lines of code:
h = quiver(...);
set(h,'MaxHeadSize',1e2,'AutoScaleFactor',1);
Check out arrow3() from the MATLAB file-exchange
https://www.mathworks.com/matlabcentral/fileexchange/14056-arrow3
In addition to these examples.
https://kr.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/14056/versions/16/previews/arrow3_examples.html
It is faster than the annotation command, and produces similar results.
Using the above examples
headWidth =0.8; % 1/10 of annotation
headLength=0.8; % 1/10 of annotation
LineLength = 0.08; % same as annotation
[x,y] = meshgrid(0:0.2:2,0:0.2:2);
u = cos(x).*y;
v = sin(x).*y;
figure();
%hq = quiver(x,y,u,v);
p1 = [x(:) y(:)]; % data start point
u = u(:); v=v(:);
arrow3(p1,p1+LineLength*[u,v],'k',headWidth,headLength);
Sorry I can't post a picture of this plotted, since I need to earn more reputation points. The arrowheads are closed and all similar size, like the annotation command would give.