matlab selecting regions in matlab plot - matlab

I have a problem when i am working with plots in Matlab. Following are my issues with Plots:
How can one select Regions after plotting data using mouse?
After selecting the Regions how to get data from that region?
Any Ideas?

Selecting regions with a mouse is quite easy using the rbbox function.
First you add a ButtonDownFcn to the axes you are drawing rbbox on.
hax = axes( ... , 'ButtonDownFcn', #OnClickAxes);
Then you call rbbox within the callback like this
function OnClickAxes( hax, evt )
point1 = get(hax,'CurrentPoint'); % hax is handle to axes
rbbox;
point2 = get(hax,'CurrentPoint'); % hax is handle to axes
end
Here point1 and point2 will define the two corners of the rectangle drawn by your mouse in data coordinates. Type doc rbbox at matlab prompt for more information
Now to answer your second question for 2-D plots.
This bit of code will extract and return the data within the selected region for all lines within an axes.
https://gist.github.com/3107790

Related

Clickable/ Interactive contour plots in Matlab

I have formed a 2D matrix of 180X360. In fact, it is a LatXLong grid of 1°X1°. Each grid point has a value calculated according to my algorithm.
If I want to plot this LatXLong grid using any contour function, it is easy to do.
Now, what I need to do is to make this grid a clickable/ interactive contour plot in a way that when the user clicks anywhere on my grid plot, he gets an onscreen information or a further plot to be displayed specifically related to that grid point.
In short, I want to make a grid/contour plot in which all grid points are hyperlinks and linked to further background information.
check this answer:
if you don't want to have the variable as title of the plot, you can modify the code as:
function mouseExample()
h = plot(rand(10,1), 'o-');
set(h, 'ButtonDownFcn',#buttonDownCallback)
function out = buttonDownCallback(o,e)
p = get(gca,'CurrentPoint');
out = p(1,1:2);
% title( sprintf('(%g,%g)',p) ) % --> no need this line anymore
end
end
the information is saved in the P variable that you can use later.
To get started, look into ginput and text. ginput will let you click on points in your plot and return the coordinates to some function that can generate information to be displayed in the current plot using text of by opening another figure.
You can use ginput in a loop to display multiple data points as you go:
for t = 1:10
[x,y] = ginput(1);
text(x,y,'some info');
end
I don't know of a way to remove the gird lines. NKN's solution might do that for you.

Holding multiple axes' plots in Matlab GUI:

I'm currently developing a GUI (programatically. No GUIDE has been used) for a project and I need to place 11 axes on the same GUI. I'm using the axes command to get the handles of the 11 controls:
h.AXES_ALL(1)=axes('parent',h.fig,'position',[L1 T W H]);
h.AXES_ALL(2)=axes('parent',h.fig,'position',[L2 T W H]);
h.AXES_ALL(3)=axes('parent',h.fig,'position',[L3 T W H]);
...
They all have the same dimensions and I'm using the for instruction to plot the data:
for i=1:11
set(h.PLOT(i),'parent',h.AXES_ALL(i),'XData',x_data,'YData',y_data);
end
But the problem is that the last plot (the 11th) is the one that is shown on the axes control (the 11th) and all the other axes are empty. My objective is to plot 11 curves on 11 different axes controls. They aren't located in the same position, just for the record.
THanks in advance!
Charlie
You said in your comment that you start with a single axes handle:
ha = axes;
And you try to create two plots with the same parent axes, but it does not work as you intended:
>> h.PLOT(1:2) = plot(ha,0,0)
h.PLOT =
195.0035 195.0035
That just replicated the same plot series handle. So, when you go to set the plot data and parent axes for each plot, you are just moving the plot from axes to axes, updating the data while you go.
Use the plot command in a loop, using the appropriate axes handle for each plot:
for ip=1:11,
h.PLOT_ALL(ip) = plot(h.AXES_ALL(ip),...);
end
Then when you update the plot's XData and YData as you want to do, you do not have to change the parent axes.

Drawing with mouse on the GUI in matlab

I want to have a program in matlab with GUI, at run the program, user can draw anythings with mouse on the axes in GUI, and i want to saving created image in a matrix. how can i to do this?
Finally i find a good code and i have changed some parts for customizing for me. with this way, user can drawing anythings in the axes with mouse :
function userDraw(handles)
%F=figure;
%setptr(F,'eraser'); %a custom cursor just for fun
A=handles.axesUserDraw; % axesUserDraw is tag of my axes
set(A,'buttondownfcn',#start_pencil)
function start_pencil(src,eventdata)
coords=get(src,'currentpoint'); %since this is the axes callback, src=gca
x=coords(1,1,1);
y=coords(1,2,1);
r=line(x, y, 'color', [0 .5 1], 'LineWidth', 2, 'hittest', 'off'); %turning hittset off allows you to draw new lines that start on top of an existing line.
set(gcf,'windowbuttonmotionfcn',{#continue_pencil,r})
set(gcf,'windowbuttonupfcn',#done_pencil)
function continue_pencil(src,eventdata,r)
%Note: src is now the figure handle, not the axes, so we need to use gca.
coords=get(gca,'currentpoint'); %this updates every time i move the mouse
x=coords(1,1,1);
y=coords(1,2,1);
%get the line's existing coordinates and append the new ones.
lastx=get(r,'xdata');
lasty=get(r,'ydata');
newx=[lastx x];
newy=[lasty y];
set(r,'xdata',newx,'ydata',newy);
function done_pencil(src,evendata)
%all this funciton does is turn the motion function off
set(gcf,'windowbuttonmotionfcn','')
set(gcf,'windowbuttonupfcn','')
The ginput function gets the coordinates of moueclicks within a figure. You could use these as points of a line, polygon, etc.
If this doesn't fit your needs you need to decribe what exactly you expect the user to draw.
For freehand drawing this might be helpful:
http://www.mathworks.com/matlabcentral/fileexchange/7347-freehanddraw
The only way I know to interact with matlab windows using a mouse is ginput, but this will now let you draw anything with fluidity.
There are ways to use Java Swing components in matlab check http://undocumentedmatlab.com/ for more info.
EDIT: You may want to check this out as well.
http://blogs.mathworks.com/videos/2008/05/27/advanced-matlab-capture-mouse-movement/

Make clicking MATLAB plot markers plot subgraph

In Matlab 2011b, I have a multidimensional matrix which is to be initially presented as a 2D plot of 2 of its dimensions. I wish to make the markers clickable with the left mouse button. Clicking on a marker draws a new figure of other dimensions sliced by the clicked value.
This question is related to Matlab: Plot points and make them clickable to display informations about it but I want to run a script, not just pop up data about the clicked point.
Googling hinted that ButtonDownFcn could be used, but examples I found require manually plotting each point and attaching a handler, like so:
hp = plot(x(1), y(1), 'o');
set(hp, 'buttondownfcn', 'disp(1)');
As there are many markers in the main graph, is it possible to just attach a handler to the entire curve and call the subgraph-plotting function with the index (preferable) or coordinates of the marker clicked?
this is an idea of what you need, and should help get you started if I understand your requirements.
In this case, when you select a curve, it will draw it in the bottom subplot preserving the color.
function main
subplot(211)
h = plot (peaks);
set (h,'buttondownfcn', #hitme)
end
function hitme(gcbo,evendata)
subplot (212)
hold on;
col = get (gcbo,'Color');
h2 = plot (get (gcbo,'XData'),get (gcbo,'YData'));
set (h2,'Color', col)
pt = get (gca, 'CurrentPoint');
disp (pt);
end
You can explore your options for get by simply writing get(gcbo) in the hitme function.

MATLAB - How to zoom subplots together?

I have multiple subplots in one figure. The X axis of each plot is the same variable (time). The Y axis on each plot is different (both in what it represents and the magnitude of the data).
I would like a way to zoom in on the time scale on all plots simultaneously. Ideally by using the rectangle zoom tool on one of the plots, and having the other plots change their X limits accordingly. The Y limits should remained unchanged for all of this. Auto fitting the data to fill the plot in the Y direction is acceptable.
(This question is almost identical to Stack Overflow question one Matplotlib/Pyplot: How to zoom subplots together? (except for MATLAB))
Use the built-in linkaxes function as follows:
linkaxes([hAxes1,hAxes2,hAxes3], 'x');
For more advanced linking (not just the x or y axes), use the built-in linkprop function
Use linkaxes as Yair and Amro already suggested. Following is a quick example for your case
ha(1) = subplot(2,1,1); % get the axes handle when you create the subplot
plot([1:10]); % Plot random stuff here as an example
ha(2) = subplot(2,1,2); % get the axes handle when you create the subplot
plot([1:10]+10); % Plot random stuff here as an example
linkaxes(ha, 'x'); % Link all axes in x
You should be able to zoom in all the subplots simultaneously
If there are many subplots, and collecting their axes handle one by one does not seem a clever way to do the job, you can find all the axes handle in the given figure handle by the following commands
figure_handle = figure;
subplot(2,1,1);
plot([1:10]);
subplot(2,1,2);
plot([1:10]+10);
% find all axes handle of type 'axes' and empty tag
all_ha = findobj( figure_handle, 'type', 'axes', 'tag', '' );
linkaxes( all_ha, 'x' );
The first line finds all the objects under figure_handle of type "axes" and empty tag (''). The condition of the empty tag is to exclude the axe handles of legends, whose tag will be legend.
There might be other axes objects in your figure if it's more than just a simple plot. In such case, you need to add more conditions to identify the axes handles of the plots you are interested in.
To link a pair of figures with linkaxes use:
figure;imagesc(data1);
f1h=findobj(gcf,,’type’,’axes’)
figure;imagesc(data2);
f2h=findobj(gcf,,’type’,’axes’)
linkaxes([f1h,f2h],’xy’)