I just can't find it. How to set up axis and labels in matlab so they cross at zero point, with the labels just below the axis not on left/bottom of the plot ?
If I didn't make myself clear - I just want the plot to look like like we all used to draw it when in school. Axes crossing, 4 quadrants, labels right below axis, curve ... as it goes.
Anyone knows how to set it up ?
You should check out two submissions on The MathWorks File Exchange:
PlotAxisAtOrigin by Shanrong Zhang
axescenter by Matt Fig
Hopefully these will work with whatever MATLAB version you have (the submission from Matt Fig is the most recently updated one).
As of Matlab release R2015b, this can be achieved with the axis property XAxisLocation and YAxisLocation being set to origin.
In other words,
x = linspace(-5,5);
y = sin(x);
plot(x,y)
ax = gca;
ax.XAxisLocation = 'origin';
ax.YAxisLocation = 'origin';
Example is taken from MATLAB official documentation:
Display Axis Lines through Origin
Controlling Axis Location
Related
I'm the MatLab newbie and I need some help to create a linear and non-linear axis in one chart.
I need to make chart with 2 different X-axes. One X-axis displays 1000/T at the bottom and the second X-axis displays a T at the top of the chart.
Example figure:
Do you have any idea how to solve this problem in MatLab?
Thanks.
This can be done by simply creating a second axes object at the same place as the first. Let's first create some data:
x1 = 1:0.1:3.5;
x2 = 1./x1;
y = (0.5*(x1-2)).^3;
Now we can create a normal plot with the first axes, and get the axes handle:
plot(x1,y,'-r');
ax(1) = gca;
Then we create the second axes object, at the same position as the first, and make the color none so it is transparent and the plot from below is still visible. As this adds a second Y axis too, we simply remove the Y ticks of the second axis.
ax(2) = axes('Position',ax(1).Position,'XAxisLocation','top','Color','none');
set(ax(2),'YTick',[]);
Now lets just format the second X axis as we like. Let's set the limits to the minimum and maximum of the x2 vector, and make it logarithmic:
set(ax(2),'XLim',[min(x2),max(x2)]);
set(ax(2),'XScale','log');
Now we still have the problem that the XTicks of ax(1) are also displayed at the top, and the XTicks of ax(2) are displayed at the bottom. This can be fixed by removing the box around the existing axes and creating a third axis without any ticks but with a box.
box(ax(1),'off');
box(ax(2),'off');
ax(3) = axes('Position',ax(1).Position,'XTick',[],'YTick',[],'Box','on','Color','none');
Now finally we can link the axes to be able to zoom correctly
linkaxes(ax);
And that should be it...
There is documentation for having a graph with two y-axes on the Mathworks website . .
http://de.mathworks.com/help/matlab/creating_plots/plotting-with-two-y-axes.html
It should be trivial to covert the concepts to the x-axis.
I struggle a little bit with overlapping axis numbers of the y and x axis like it is shown in the image. I'd like to keep the size of the numbers and therefore think that simply shifting the numbers away from the axis itself would be an appropriate way to handle this issue.
Is there a possibility to do that?
Thanks in advance,
Joe
Here is a little workaround using text annotations. Basically you clear the current XTick labels and replace them with similar labels, but you can specify the distance from the axis:
clc
clear
close all
x = 1:20;
hPlot = plot(x,sin(x));
set(gca,'xaxisLocation','top');
set(gca,'XTickLabel',[]); %// Clear current XTickLabel
ylim = get(gca,'YLim'); %// Get y limit of the plot to place your text annotations.
for k = 2:2:20
text(k,ylim(2)+0.1,num2str(k),'HorizontalAlignment','Center') %// Play with the 'ylim(1) -0.1' to place the label as you wish.
end
Giving this:
Of course now it's exaggerated and you can do the same for the y axis if you want (using the 'XLim' property of the current axis,gca).
I'm creating a 2d MATLAB plot. I'm setting the limits of my x axis, and letting my y axis auto-adjust (by setting its limits to [-inf inf]). After creating my plot, I need to check what my y axis has auto adjusted to (as I'm going to create a heatmap to put under my plot).
Unfortunately, ylim (and similar functions) only produce [-inf inf], not whatever the axes have adjusted to.
Some code which reproduces this problem (much more simply than my actual code) is:
function createplot(xbounds)
x = xbounds(1):0.5:xbounds(2);
y = x.^2;
plot(x,y);
axis([xbounds,-inf,inf]);
createplot([0,10])
which produces a parabolic plot with y limits = [0,100]. However, ylim = [-inf, inf].
Any help would be appreciated!
/ Wilbur
As #Shai suggested, axis can give info regarding the ylimits without the need to set them to [-inf,inf] or use axis to set the x-axis bounds:
xbounds=[1 10]
x = xbounds(1):0.5:xbounds(2);
y = x.^2;
plot(x,y);
xlim([xbounds(1) xbounds(2)]);
v=axis
v =
1 10 0 100
Looking at #natan's answer I think the solution to your problem is
Do not use [-inf inf] for auto-adjusting axis limits.
If you want Matlab to auto adjust some of your axes limits and manually set others, then you should use either xlim, ylim or zlim for the specific axis you wish to set and leave all the other unchanged so Matlab can set them automatically.
This way you will not override the values Matlab assigns to those axes and you will be able to read them using axis, xlim, ylim or zlim.
Please see #natan's answer for corrected code.
I just can't find it. How to set up axis and labels in matlab so they cross at zero point, with the labels just below the axis not on left/bottom of the plot ?
If I didn't make myself clear - I just want the plot to look like like we all used to draw it when in school. Axes crossing, 4 quadrants, labels right below axis, curve ... as it goes.
Anyone knows how to set it up ?
You should check out two submissions on The MathWorks File Exchange:
PlotAxisAtOrigin by Shanrong Zhang
axescenter by Matt Fig
Hopefully these will work with whatever MATLAB version you have (the submission from Matt Fig is the most recently updated one).
As of Matlab release R2015b, this can be achieved with the axis property XAxisLocation and YAxisLocation being set to origin.
In other words,
x = linspace(-5,5);
y = sin(x);
plot(x,y)
ax = gca;
ax.XAxisLocation = 'origin';
ax.YAxisLocation = 'origin';
Example is taken from MATLAB official documentation:
Display Axis Lines through Origin
Controlling Axis Location
I'm using polar plots (POLAR(THETA,RHO)) in MATLAB.
Is there an easy way to fix the range for the radial axis to say, 1.5?
I'm looking for something analogous to the xlim, ylim commands for cartesian axes. Haven't found anything in the docs yet.
this worked for me... i wanted the radius range to go to 30, so i first plotted this
polar(0,30,'-k')
hold on
and then plotted what i was actually interested in. this first plotted point is hidden behind the grid marks. just make sure to include
hold off
after your final plotting command.
Here's how I was able to do it.
The MATLAB polar plot (if you look at the Handle Graphics options available) does not have anything like xlim or ylim. However, I realized that the first thing plotted sets the range, so I was able to plot a function with radius range [-.5 .5] on a [-1 1] plot as follows:
theta = linspace(0,2*pi,100);
r = sin(2*theta) .* cos(2*theta);
r_max = 1;
h_fake = polar(theta,r_max*ones(size(theta)));
hold on;
h = polar(theta, r);
set(h_fake, 'Visible', 'Off');
That doesn't look very good and hopefully there's a better way to do it, but it works.
Simple solution is to make a fake graph and set its color to white.
fake=100;
polar(0,fake,'w');
hold on;
real=10;
polar(0,real,'w');
In case anyone else comes across this, here's the solution:
As Scottie T and gnovice pointed out, Matlab basically uses the polar function as an interface for standard plots, but with alot of formatting behind the scenes to make it look polar. Look at the values of the XLim and YLim properties of a polar plot and you'll notice that they are literally the x and y limits of your plot in Cartesian coordinates. So, to set a radius limit, use xlim and ylim, or axis, and be smart about the values you set:
rlim = 10;
axis([-1 1 -1 1]*rlim);
...that's all there is to it. Happy Matlabbing :)