Matlab - Make Only Part of Axis Title bold - matlab

i have a 2x2 subplot for data that varies on 2 dimensions- i want a shared title for plots [(1,1) and (1,2)] vs [(2,1) and (2,2)] as well as a shared title for plots
[(1,1) (2,1)] vs [(1,2) and (2,2)]. Separately, i need x and y labels for each of the 4 subplots.
I am working with Matlab R2021a
is there a way to make the shared axis titles bold while keeping each individual subplot axis title not bold?
Thanks so much

See the offical document
ax = subplot(2,2,1);
ax.TitleFontWeight = 'normal';

Related

how to find and change all the default figure setting in Matlab?

This tutorial explains how to change certain default settings of Matlab figures, but what about the properties not listed there? For example, if I want to change the font size of the x-axis label and make the y-axis label in Latex style, whats the name for these properties? (what's the xxx in defaultxxx)
In other words, I'm looking for something similar to this matplotlib stylesheet (but for Matlab) where I can easily find the names of the properties I'm looking for so I can just change the values easily.
MATLAB has a built-in figure editor, so you can do pretty much anything there. When you plot something, in the figure, go to View > Property editor and you try different things.
If you want to do it manually, the problem is that there is not just one object in the plot figure. You can generally look at the options for figures, axes, plot and surface. However, it it possible that you will have to look further for some more specific types of figures. Useful things can be found here, that are not in the official MATLAB documentation, but you must usually search a lot.
I was looking at the link you provided for matplotlib and decided to do something similar as an example of working with MATLAB plots. The following code:
x = linspace(0, 2*pi, 100);
y = sin(x);
% Plot a sinus curve, make the data depicted with red line and red filled dots
plot(x, y, 'r-o','MarkerFaceColor','r')
set(gca, ... % Get current axes
'Color','k', ... % Set plot background color to black
'XColor',[1 1 1], ... % Set color of x axis to white
'YColor',[1 1 1], ... % Set color of y axis to white
'GridColor',[1 1 1], ... % Set color of grid to white
'GridLineStyle','--', ... % Set the grid to be dashed
'YTick',-1:0.25:1) % Set Y axis ticks from -1 to 1 with step 0.25
set(gcf,'Color','k') % Set background of the current figure to black
xlabel('Some x axis / Units') % Set X axis label
ylabel('Some y axis / Units') % Set Y axis label
grid on % Make the grid shown
And the result should look like this:
By the way, you can use some basic LaTeX notation in MATLAB without changing anything. Try writing something like
xlabel('\rho_{0} / kg m^{-3}')

Multiple vertical histograms plot in matlab

Is it possible to make multiple vertical histograms plot in Matlab into one? Much like the excel sheet enclosed ( https://drive.google.com/file/d/1H_mbyrIoln3XrnK1hLajnVNBKn13y_np/view?usp=sharing )
I want to make a plot of many vertical histogram plots into one figure, by importing excel-files, where on the y axis it has the elevation, the x axis the distance between the histogram vertical lines and the length of the histogram bars is the values in the excel sheet. The vertical height of each bar is 5.
Is this even possible? I have to put in a number of conditions for Matlab to know where to plot, but could some one show me the basic methodology?
Help would be very much appreciated!
The problem is that the parent of a Baseline object is the Axis, which prevents us from doing something like
barh(bins1,counts1,'Basevalue',baseline1); hold on;
barh(bins2,counts2,'Basevalue',baseline2); hold off;
because the plots will automatically share the second baseline value set. There might be a workaround for this that I do not know of, so I invite anybody who knows it to show me how its done.
For now, I was able to sort-of replicate the plot you posted a picture of in a much less elegant way. I will post code below, but before I do, I would like to argue against the use of a plot like this. Why? Because I think it is confusing, as the x-axis both relates to the plot number as well as the bin count numbers. You are in fact trying to display a 3-D data set, the three dimensions being bins, bin counts, and 'histogram number'. A plethora of methods exist for displaying 3-D data, and a series of 2-D histograms may not be the best way to go.
That being said, here is a code that more-or-less creates the picture above, as promised. Any changes you may want to make will be more cumbersome than usual :-)
testData = randn(10000,1); % Generate some data
[counts,bins] = hist(testData); % Bin the data
% First histogram
baseline1 = 0;
p1=subplot(1,3,1); barh(bins,counts,'BaseValue',baseline1);
xticks(baseline1); xticklabels({0}); % Graph number on x axis at baseline (0)
box off; % Remove box on right side of plot
ylabel('Property');
% Second histogram
baseline2 = max(counts)*1.2;
sepdist = baseline2-baseline1; % Distance that separates two baselines
counts2 = baseline2 + counts;
p2=subplot(1,3,2); barh(bins,counts2,'BaseValue',baseline2)
xticks(baseline2); xticklabels({1}); % Graph number on x axis at baseline
box off;
Y=gca; Y.YAxis.Visible='off';
p1p=p1.Position; p2p=p2.Position;
p2p(1)=p1p(1)+p1p(3); p2.Position=p2p; % Move subplot so they touch
% Third histogram
baseline3 = baseline2 + sepdist;
counts3 = baseline3+counts;
p3=subplot(1,3,3); barh(bins,counts3,'BaseValue',baseline3)
xticks(baseline3); xticklabels({2});
Y=gca; Y.YAxis.Visible='off';
box off
p3p=p3.Position;
p3p(1)=p2p(1)+p2p(3); p3.Position=p3p;
% Add x-label when you are done:
xl=xlabel('Test xlabel'); xl.Units='normalized';
% Fiddle around with xl.Position(1) until you find a good centering:
xl.Position(1) = -0.49;
Result:

How to plot contours with selected colors and formatted labels

I'm trying to plot contour using my computed data with limited contour labels and and colors as given in the top panel of this image:
But I ended up with a slightly different plot (see the plot in the bottom of the above image).
I want to modify my plot with the following three specifications
Restrict contour labels in 2 or 3 decimal places
Remove plot labels in the area where the contours are too close to each other.
Plot with two colors as in the first image
Here is my code:
f=load('fort.15');
ngridx=180;
ngridy=180;
x=f(:,3);
y=f(:,4);
z=f(:,5);
xlin=linspace(min(x),max(x),ngridx);
ylin=linspace(min(y),max(y),ngridy);
[X,Y]=meshgrid(xlin,ylin);
Z=griddata(x,y,z,X,Y,'linear');
[c,h] = contour(X,Y,Z,20);
set(h,'LineWidth',2,'LineColor',rgb('SteelBlue'),'ShowText','on',...
'LabelSpacing',800 )
axis([0 6 -5 7])
I'm not an expert in Matlab. Please help me get the right plot.
I'm attaching my data file here.
Well, I got only 2 of 3. Deine the level in which the color has to change (here scl) and you good to go:
scl = 6.5; % switch color level;
[c1,h1] = contour(X,Y,Z,scl:max(Z(:)),'Color','r');
hold on
[c2,h2] = contour(X,Y,Z,min(Z(:)):scl,'Color','b');
clabel(c2,h2);
axis([0 6 -5 7])
The idea here is to builed your plot from two contour objects, using hold on command. the vector scl:max(Z(:)) define the levvels to show in the first contour, and the get the red color and no lables. And a similar logic works for the secound contour.
If you want to lable some red contours, or remove lables from the blue ones, you need to replace h2 in the clabel function with a vector of the levels you want to lable. If you will be mo specific in the comments I'll update my answer.
Changing the formatting of the lables, is probably possible somehow, but it's really not trivial, so I left it by now.

How to set x and y values when using bar3 in Matlab?

Quick version
How can I control the x- and y-values for a 3-d bar plot in Matlab?
Details
Say we have an 10 x 20 data matrix and we plot it using bar3, and we want to set the x- and y-values. For instance:
foodat = rand(10,20);
xVals = [5:14];
yVals = [-3:16];
bar3(xVals, foodat);
xlabel('x'); ylabel('y');
Is there a way to feed it the yVals as well? Otherwise the y axes always defaults to [1:N].
Note I don't just want to change the labels using XTickLabel and YTickLabel. I need to change the actual values on the axes, because I am plotting multiple things in the same figure. It isn't enough to just change how the (wrong) axis ticks are labeled. So this is different from issues like this:
How can I adjust 3-D bar grouping and y-axis labeling in MATLAB?
Other things I have tried
When I try changing the xvals with:
set(gca,'XTick', xVals)
set(gca,'YTick', yVals)
The values are taken in, but actually show up on the wrong axes, so it seems x and y axes are switched using bar3. Plus, it is too late anyway as the bar graph was already plotted with the wrong x- and y-values, so we would end up giving ticks to empty values.
Note added
Matlab tech support just emailed me to let me know about the user contributed function scatterbar3, which does what I want, in a different way than the accepted answer:
http://www.mathworks.com/matlabcentral/fileexchange/1420-scatterbar3
I found a way of doing it. Ill give you a piece of code, then you'll need to "tidy up" , mainly the axis limits and the Xticks, as bar3 does set up the Xticks inside, so if you want others you'll need to set them manually yourself.
So the trick here is to get the Xdata from the bar3 handle. The thing here is that it seems that there is a handle for each row of the data, so you need to iterate for each of them. Here is the code with the current output:
foodat = rand(20,10);
xVals = [5:14];
yVals = [-3:16];
% The values of Y are OK if called like this.
subplot(121)
bar3(yVals, foodat);
subplot(122)
h=bar3(yVals, foodat);
Xdat=get(h,'XData');
axis tight
% Widdth of barplots is 0.8
for ii=1:length(Xdat)
Xdat{ii}=Xdat{ii}+(min(xVals(:))-1)*ones(size(Xdat{ii}));
set(h(ii),'XData',Xdat{ii});
end
axis([(min(xVals(:))-0.5) (max(xVals(:))+0.5) min(yVals(:))-0.5, max(yVals(:))+0.5])
Note: Y looks different but is not.
As you can see now the X values are the ones you wanted. If you'd want other size than 1 for the intervals between them you'd need to change the code, but you can guess how probably!

Compress the size or reduce the line spacing of a legend in matlab figures

I'm trying to make a legend in a matlab figure that takes less space, in particular vertical size. Ideally, if I could change the inter-line spacing of the legend, this would have solved it, but I can't seem to find a way to do it.
I've searched around in Mathworks questions and Google. I've even tried to "write" from scratch the legend, but it doesn't work when I try to export to eps.
Is there a way to control the inter-line spacing in Matlab's legend? something undocumented maybe?
One way would be to adjust the aspect ratio of the legend:
set(h,'PlotBoxAspectRatioMode','manual');
set(h,'PlotBoxAspectRatio',[1 0.8 1]);
(Default is [1 1 1]).
You can also play with the exact positioning of the various legend elements. If h is the handle for your legend:
hc = get(h,'Children');
Now, hc will be of length 3 x the number of items in your legend.
hc(1) is the marker, hc(2) is the line, hc(3) is the text.
(and so on for subsequent items).
hc(1) will have a entry YData(vertical position, single value), hc(2) also has YData (vertical position - vector of two identical values), and hc(3) contains Position - [x y z] vector. The Y values for all these three should be the same.
Obtain the y-positions:
yd = zeros(length(hc)/3,1);
for n = 1:length(yd);
yd(n) = get(hc(1+(n-1)*3),'YData');
end
Assuming your legend doesn't have any text that goes over more than one line,yd should be evenly spaced steps. Define a new spacing of your choice, yd2.
Set new positions:
% markers
for n = 1:length(yd2)
set(hc(1+(n-1)*3),'YData',yd2(n));
end
% lines
for n = 1:3
set(hc(2+(n-1)*3),'YData',[yd2(n),yd2(n)]);
end
% text
for n = 1:3;
pos = get(hc(3+(n-1)*3),'Position');
pos(2) = yd(n);
set(hc(3+(n-1)*3),'Position',pos);
end
Problem - this shifts all the text and markers but doesn't change the border box. The easiest way if trying to make fine adjustments is to first define the final size/position of the legend, and then reposition/resize elements within to taste.
Also, you may find that when writing out images MATLAB helpfully redraws the image, resetting your adjustments. See this blog post on Undocumented MATLAB for info on that.