Is it possible to create a semilog plot (semilogx, semilogy, loglog) within a semilog plot? I need to have a zoom-in plot. Most solutions I found only solve for linear scale but not log scale.
Try using axes, for example:
x = linspace(0,1);
figure(1)
% plot on large axes
semilogy(x,1./x)
% create smaller axes in top right, and plot on it
axes('Position',[.55 .55 .33 .33])
box on
loglog(x,exp(x))
Related
I would like to plot a contour or contour3 with labeled levels over a surf plot with the same data using Matlab R2015b. Finally the figure is shown from above (the view in negative z-direction) to see the result.
My problem: The labels seem to disappear in the surf area - the product lacks the intended information.
My current test-code with the best result so far:
[X,Y,Z] = peaks;
v = -6:2:8;
hold on
surf(X,Y,Z)
shading interp
contour3(X,Y,Z,v,'k--','ShowText','on')
hold off
colormap default
caxis([-7,9])
view(0,90)
I am not yet allowed to post a picture of the result ..
Related questions in my consideration would be how to change contourf plots location on z-axis or shift the z-value of contour plot in Matlab 2014b to change the z-axis-property of a normal contour plot but they were no solution to my problem or did not work at all.
I finally understood your problem, you can solve it by doing all in 2D like so
[X,Y,Z] = peaks;
v = -6:2:8;
hold on
contourf(x,y,z,500,'LineStyle','none');
[C,h]=contour(x,y,z,v,'k--');
clabel(C,h,'FontSize',15);
caxis([-7,9])
view(0,90)
Using the function imagesc in Matlab, I plot my (X,Y, Z) data-X array distance, Y array time, and my data Z = Z(X,Y) a matrix.
I notice that the 80% of the image has one color, because the change of Z data occurred only in the end of X for almost all Y.
Right now I use colormap('hsv') which give I think the largest range of different colors.
I need to change the colorbar range to a logarithmic one to improve visual the range of the change of my output data through time along the distance X.
I have used also contourf but still I am not sure if it will better to use this function and not imagesc which the output is more smoothed.
Please, any idea, any method or any small script that I could use to show visual the difference in data in logarithmic scale in 2D using imagesc or another build in function is more than welcome!
thank you
There is a discussion at the Mathworks website where someone provided a function that does logarithmic color bars.
https://www.mathworks.com/matlabcentral/newsreader/view_thread/152310
EDIT: copying and pasting code from link
function cbar = colorbar_log(my_clim)
%COLORBAR_LOG Apply log10 scaling to pseudocolor axis
% and display colorbar COLORBAR_LOG(V), where V is the
% two element vector [cmin cmax], sets manual, logarithmic
% scaling of pseudocolor for the SURFACE and PATCH
% objects. cmin and cmax should be specified on a LINEAR
% scale, and are assigned to the first and last colors in
% the current colormap. A logarithmic scale is computed,
% then applied, and a colorbar is appended to the current
% axis.
%
% Written by Matthew Crema - 7/2007
% Trick MATLAB by first applying pseudocolor axis
% on a linear scale
caxis(my_clim)
% Create a colorbar with log scale
cbar = colorbar('Yscale', 'log');
% Now change the pseudocolor axis to a log scale.
caxis(log10(my_clim));
% Do not issue the COLORBAR command again! If you want to
% change things, issue COLORBAR_LOG again.
So I have data in the form [x y z intensity] that I plot on a scatter3 figure with xyz axes. The colour of the data is used to dictate the intensity value. Problem is, using a scatter plot means the data points show up as discrete points. What I need, is a smooth shape - so I guess I need some kind of interpolation between the points?
I've tried using trisurf, but the problem with this one is that it interpolates between points that it shouldn't. So where I should have 'gaps' in my surface, it joins up the edges instead so it fills in the gaps. See the attached pics for clarification.
Does anyone have any suggestions?
The code I use is as below (the commented out scatter3 is what does the scatter plot, the rest does the trisurf):
% Read in data
dataM = csvread('3dDispersion.csv');
% scatter3(dataM(:,1), dataM(:,2), dataM(:,3), 5, dataM(:,4),'filled');
% Plot
hold on;
x = dataM(:,1);
y = dataM(:,2);
freq = dataM(:,3);
tri = delaunay(x,y);
h = trisurf(tri, x, y, freq);
% Make it pretty
% view(-45,30);
view(3);
axis vis3d;
lighting phong;
shading interp;
Use the boundary function in Matlab. This will apply a mesh similar to shrinkwrap over your points. In order to reduce the "gap closers", you will want to increase the "shrink factor".
Try K = boundary(X,Y,Z,0.9)
Where X, Y & Z are the vectors of your data points
https://www.mathworks.com/help/matlab/ref/boundary.html
You can then use trimesh or related surface plotting functions depending on how you want to display it.
I'm trying to create a plot using the values 10^0 10^3 10^6 10^9... on the x-axis. Matlab does not automatically rescale so my values are all down in the left corner.
My current code is:
figure('name','My plot title');
hold on
plot(kap, reg, '--mo');
plot(kap, reij, '-.r*');
hold off
kap is a vector of x values -> 10^0 10^3 10^6 10^9.....,
reg and reij are measurements.
Maybe loglog, semilogx could help?
A picture of my plot: enter link description here
The problem was that I should use loglog or semilogx and not use it in a figure.
Yep, semilogx is what you want:
semilogx(kap,reg,'--mo');
loglog gives logarithmic scales for both x and y axes, and semilogy plots with a lagarithmic scale on the y axis.
x=10.^(0:3:30);
y=rand(size(x));
semilogx(x,y)
I have plotted to vectors against each other, and they are already logarithmic and everything is fine with that. But now that I have my plot i want the grid to be logarithmic. I write "grid on" in my code, and I think there should be a way to do this in the plot, but I can't remember how. How do I make the grid logarithmic?
If you use loglog, semilogx or semilogy instead of plot, the grid will automatically be on a log scale for the corresponding axes when using grid on.
If you have already plotted the axes, you can execute the following on the command line:
set(gca,'yscale','log') %# to set the y-axis to logarithmic
set(gca,'xscale','log') %# to set the x-axis to logarithmic
Have a look at axes properties to find out what else you can modify.