I need to create a GUI in Matlab that enables me to draw graphs interactively, and the give values to the edges and vertices.
I then need to return these values (x, y, value) for edges and (x1, y1, x2, y2, value) for vertices.
Unfortunately I don't even know where to start. I created a gui that lets me draw lines interactively, with 2 different methods, but I don't know how to continue. Please help.
You can always handle mouse events to enable interactive drawing. I spent some time on this and came up with the following GUI.
function interactive_graph_gui
% data
showLabels = false; % flag to determine whether to show node labels
prevIdx = []; % keeps track of 1st node clicked in creating edges
selectIdx = []; % used to highlight node selected in listbox
pts = zeros(0,2); % x/y coordinates of vertices
adj = sparse([]); % sparse adjacency matrix (undirected)
% create GUI
h = initGUI();
function h = initGUI()
h.fig = figure('Name','Interactive Graph', 'Resize','off');
h.ax = axes('Parent',h.fig, 'ButtonDownFcn',#onMouseDown, ...
'XLim',[0 1], 'YLim',[0 1], 'XTick',[], 'YTick',[], 'Box','on', ...
'Units','pixels', 'Position',[160 20 380 380]);
h.list = uicontrol('Style','listbox', 'Parent',h.fig, 'String',{}, ...
'Min',1, 'Max',1, 'Value',1, ...
'Position',[20 80 130 320], 'Callback',#onSelect);
uicontrol('Style','pushbutton', 'Parent',h.fig, 'String','Clear', ...
'Position',[20 20 60 20], 'Callback',#onClear);
uicontrol('Style','pushbutton', 'Parent',h.fig, 'String','Export', ...
'Position',[90 20 60 20], 'Callback',#onExport);
uicontrol('Style','pushbutton', 'Parent',h.fig, 'String','Delete', ...
'Position',[50 50 60 20], 'Callback',#onDelete);
h.cmenu = uicontextmenu('Parent',h.fig);
h.menu = uimenu(h.cmenu, 'Label','Show labels', 'Checked','off', ...
'Callback',#onCMenu);
set(h.list, 'UIContextMenu',h.cmenu)
h.pts = line(NaN, NaN, 'Parent',h.ax, 'HitTest','off', ...
'Marker','o', 'MarkerSize',10, 'MarkerFaceColor','b', ...
'LineStyle','none');
h.selected = line(NaN, NaN, 'Parent',h.ax, 'HitTest','off', ...
'Marker','o', 'MarkerSize',10, 'MarkerFaceColor','y', ...
'LineStyle','none');
h.prev = line(NaN, NaN, 'Parent',h.ax, 'HitTest','off', ...
'Marker','o', 'MarkerSize',20, 'Color','r', ...
'LineStyle','none', 'LineWidth',2);
h.edges = line(NaN, NaN, 'Parent',h.ax, 'HitTest','off', ...
'LineWidth',2, 'Color','g');
h.txt = [];
end
function onMouseDown(~,~)
% get location of mouse click (in data coordinates)
p = get(h.ax, 'CurrentPoint');
% determine whether normal left click was used or otherwise
if strcmpi(get(h.fig,'SelectionType'), 'Normal')
% add a new node
pts(end+1,:) = p(1,1:2);
adj(end+1,end+1) = 0;
else
% add a new edge (requires at least 2 nodes)
if size(pts,1) < 2, return; end
% hit test (find node closest to click location: euclidean distnce)
[dst,idx] = min(sum(bsxfun(#minus, pts, p(1,1:2)).^2,2));
if sqrt(dst) > 0.025, return; end
if isempty(prevIdx)
% starting node (requires a second click to finish)
prevIdx = idx;
else
% add the new edge
adj(prevIdx,idx) = 1;
prevIdx = [];
end
end
% update GUI
selectIdx = [];
redraw()
end
function onDelete(~,~)
% check that list of nodes is not empty
if isempty(pts), return; end
% delete selected node
idx = get(h.list, 'Value');
pts(idx,:) = [];
adj(:,idx) = [];
adj(idx,:) = [];
% clear previous selections
if prevIdx == idx
prevIdx = [];
end
selectIdx = [];
% update GUI
set(h.list, 'Value',max(min(idx,size(pts,1)),1))
redraw()
end
function onClear(~,~)
% reset everything
prevIdx = [];
selectIdx = [];
pts = zeros(0,2);
adj = sparse([]);
% update GUI
set(h.list, 'Value',1)
redraw()
end
function onExport(~,~)
% export nodes and adjacency matrix to base workspace
assignin('base', 'adj',(adj+adj')>0) % make it symmetric
assignin('base', 'xy',pts)
end
function onSelect(~,~)
% update index of currently selected node
selectIdx = get(h.list, 'Value');
redraw()
end
function onCMenu(~,~)
% flip state
showLabels = ~showLabels;
redraw()
end
function redraw()
% edges
p = nan(3*nnz(adj),2);
[i,j] = find(adj);
p(1:3:end,:) = pts(i,:);
p(2:3:end,:) = pts(j,:);
set(h.edges, 'XData',p(:,1), 'YData',p(:,2))
% nodes
set(h.pts, 'XData',pts(:,1), 'YData',pts(:,2))
set(h.prev, 'XData',pts(prevIdx,1), 'YData',pts(prevIdx,2))
set(h.selected, 'XData',pts(selectIdx,1), 'YData',pts(selectIdx,2))
% list of nodes
set(h.list, 'String',num2str(pts,'(%.3f,%.3f)'))
% node labels
if ishghandle(h.txt), delete(h.txt); end
if showLabels
set(h.menu, 'Checked','on')
h.txt = text(pts(:,1)+0.01, pts(:,2)+0.01, ...
num2str((1:size(pts,1))'), ...
'HitTest','off', 'FontSize',8, ...
'VerticalAlign','bottom', 'HorizontalAlign','left');
else
set(h.menu, 'Checked','off')
end
% force refresh
drawnow
end
end
It all boils down to handling the ButtonDownFcn callback of the axis object, and querying the location of the last mouse click using the CurrentPoint property.
Here is a list of the possible ways to interact with the GUI:
left-click inside the axis to create vertices
right-click on two nodes to create an edge
use the listbox to select and highlight nodes. Use the "delete" button to remove the selected vertex.
The "clear" button resets everything
The "export" button create two variables in the base workspace containing the vertices 2D coordinates (N-by-2 matrix) and the edges (as a sparse N-by-N matrix). You can use those variables with other graph functions as usual:
gplot(adj, xy, 'b.-')
Finally you can right click on the listbox. This will bring up a popup menu, containing the option to display labels for the vertices.
You can extend the above code to assign values to vertices. For example you could use the callback function of the listbox to assign values to vertices (display an input dialog when the user selects an item from the list). You could also use the same technique shown of handling the ButtonDownFcn callback. Similarly you could create a second listbox to display the edges and handle the assignment of values in the same manner... I will that part to you :)
If you want to use the mouse to draw interactively you can use the function ginput. Here there is the manual.
I found very useful also this example.
Related
Suppose I have a 5x5 matrix.
The elements of the matrix change (are refreshed) every second.
I would like to be able to display the matrix (not as a colormap but with the actual values in a grid) in realtime and watch the values in it change as time progresses.
How would I go about doing so in MATLAB?
A combination of clc and disp is the easiest approach (as answered by Tim), here's a "prettier" approach you might fancy, depending on your needs. This is not going to be as quick, but you might find some benefits, such as not having to clear the command window or being able to colour-code and save the figs.
Using dispMatrixInFig (code at the bottom of this answer) you can view the matrix in a figure window (or unique figure windows) at each stage.
Example test code:
fig = figure;
% Loop 10 times, pausing for 1sec each loop, display matrix
for i=1:10
A = rand(5, 5);
dispMatrixInFig(A,fig)
pause(1)
end
Output for one iteration:
Commented function code:
function dispMatrixInFig(A, fig, strstyle, figname)
%% Given a figure "fig" and a matrix "A", the matrix is displayed in the
% figure. If no figure is supplied then a new one is created.
%
% strstyle is optional to specify the string display of each value, for
% details see SPRINTF. Default is 4d.p. Can set to default by passing '' or
% no argument.
%
% figname will appear in the title bar of the figure.
if nargin < 2
fig = figure;
else
clf(fig);
end
if nargin < 3 || strcmp(strstyle, '')
strstyle = '%3.4f';
end
if nargin < 4
figname = '';
end
% Get size of matrix
[m,n] = size(A);
% Turn axes off, set origin to top left
axis off;
axis ij;
set(fig,'DefaultTextFontName','courier', ...
'DefaultTextHorizontalAlignment','left', ...
'DefaultTextVerticalAlignment','bottom', ...
'DefaultTextClipping','on');
fig.Name = figname;
axis([1, m-1, 1, n]);
drawnow
tmp = text(.5,.5,'t');
% height and width of character
ext = get(tmp, 'Extent');
dy = ext(4);
wch = ext(3);
dwc = 2*wch;
dx = 8*wch + dwc;
% set matrix values to fig positions
x = 1;
for i = 1:n
y = 0.5 + dy/2;
for j = 1:m
y = y + 1;
text(x,y,sprintf(strstyle,A(j,i)));
end
x = x + dx;
end
% Tidy up display
axis([1-dwc/2 1+n*dx-dwc/2 1 m+1]);
set(gca, 'YTick', [], 'XTickLabel',[],'Visible','on');
set(gca,'XTick',(1-dwc/2):dx:x);
set(gca,'XGrid','on','GridLineStyle','-');
end
I would have thought you could achieve this with disp:
for i=1:10
A = rand(5, 5);
disp(A);
end
If you mean that you don't want repeated outputs on top of each other in the console, you could include a clc to clear the console before each disp call:
for i=1:10
A = rand(5, 5);
clc;
disp(A);
end
If you want to display your matrix on a figure it is quite easy. Just make a dump matrix and display it. Then use text function to display your matrix on the figure. For example
randMatrix=rand(5);
figure,imagesc(ones(20));axis image;
hold on;text(2,10,num2str(randMatrix))
If you want to do it in a for loop and see the numbers change, try this:
for i=1:100;
randMatrix=rand(5);
figure(1),clf
imagesc(ones(20));axis image;
hold on;text(2,10,num2str(randMatrix));
drawnow;
end
I am trying to change the radius of a sphere by using left and right arrow keys, plotted in a MATLAB figure. For example by pressing right arrow, the value of radius increases by one and then plot the new sphere with the updated radius. Similarly, pressing left arrow key decreases the radius by one and then plots a smaller sphere. However, I want this change to be limited between 1 and rmax.
I got some ideas of how I can approach after reading this post but still it is not what I am looking for. Therefore, I used two global variables to achieve this task in order to somehow pass the information by reference to KeyPressFcn so when a key is pressed KeyPressFcn know what those limits are. In the example below, the code does increase and decrease the radius by one but it is it does not restrict the change of radius within the specified range after left and right arrows are hit.
Is there a better way of approaching this? How can I pass the value of radius and its limits to KeyPressFcn? I want KeyPressFcn to know how much it can change the radius when left and right arrows are pressed.
function animateme()
fig_h = figure;
set(fig_h,'KeyPressFcn', #key_pressed_fcn);
global r rmax
p0 = [0 0 0];
[x,y,z] = sphere;
rmax = 10;
r = 1;
while 1==1
h = surf(x*r+p0(1), y*r+p0(2), z*r+p0(3));
set(h, 'FaceAlpha', 0.5, 'FaceColor', rand([1 3]))
axis equal;
pause
end
function key_pressed_fcn(fig_obj, eventDat)
global r rmax
if strcmpi(eventDat.Key, 'rightarrow')
r = r + 1;
if r < 1
r = 1;
end
elseif strcmpi(eventDat.Key, 'leftarrow')
r = r - 1;
if r > rmax
r = rmax;
end
end
disp(r)
First of all, don't use global variables as there is (almost) always a better way of accomplishing the same thing.
Here is an example by using nested functions which automatically have access to the variables within the parent function's workspace.
function animateme()
fig = figure();
hax = axes('Parent', fig);
set(fig, 'KeyPressFcn', #keypress)
p0 = [0,0,0];
[x,y,z] = sphere();
% Specify limits here which are accessible to nested functions
rmax = 10;
r = 1;
h = surf(x,y,z, 'Parent', hax);
% Subfunction for re-plotting the data
% This prevents you from needing a while loop
function redraw()
set(h, 'XData', x * r + p0(1), ...
'YData', y * r + p0(2), ...)
'ZData', z * r + p0(3));
set(h, 'FaceAlpha', 0.5, ...
'FaceColor', rand([1 3]))
axis(hax, 'equal')
drawnow
end
% Go ahead and do the first redraw
redraw();
% Callback to process keypress events
function keypress(~, evnt)
switch lower(evnt.Key)
case 'rightarrow'
r = min(r + 1, rmax);
case 'leftarrow'
r = max(1, r - 1);
otherwise
return
end
% Always do a redraw
redraw();
end
end
Another option is to store the current value of r within the graphics objects themselves using the UserData field. So you could put it in the surf plot itself. This is actually my preferred method because then your callback function can live anywhere and still have access to the data it needs.
function animateme()
fig = figure();
% Data to store for plotting
data.p = [0,0,0];
data.r = 1;
data.rmax = 10;
% Create a blank surface for starters
h = surf(nan(2), nan(2), nan(2));
set(h, 'UserData', data);
% Update the display of the surface
redraw(h);
% Set the callback and pass the surf handle
set(fig, 'KeyPressFcn', #(fig, evnt)keypress(h, evnt))
end
function redraw(h)
% Get the stored data from the graphics object
userdata = get(h, 'Userdata');
[x,y,z] = sphere();
set(h, 'XData', x * userdata.r + userdata.p(1), ...
'YData', y * userdata.r + userdata.p(2), ...
'ZData', z * userdata.r + userdata.p(3));
set(h, 'FaceAlpha', 0.5, ...
'FaceColor', rand([1 3]))
axis equal
drawnow;
end
function keypress(h, evnt)
% Get the stored data
userdata = get(h, 'Userdata');
switch lower(evnt.Key)
case 'rightarrow'
userdata.r = min(userdata.r + 1, userdata.rmax);
case 'leftarrow'
userdata.r = max(1, userdata.r - 1);
otherwise
return;
end
% Update the stored value
set(h, 'UserData', userdata);
redraw(h);
end
I want Matlab to execute a function that takes the specific point I clicked on as an input, so for example, if I plot
plot(xy(:,1),xy(:,2))
scatter(xy(:,1),xy(:,2))
and then click on a specific point (see figure), it will execute a callback function whose inputs are not only the x,y coordinate of that point but also its index value (ie its the 4th row of variable xy)
Thanks alot!
This can be done by using the ButtonDownFcn property of Scatter objects.
In the main script:
% --- Define your data
N = 10;
x = rand(N,1);
y = rand(N,1);
% --- Plot and define the callback
h = scatter(x, y, 'bo');
set(h, 'ButtonDownFcn', #myfun);
and in the function myfun:
function myfun(h, e)
% --- Get coordinates
x = get(h, 'XData');
y = get(h, 'YData');
% --- Get index of the clicked point
[~, i] = min((e.IntersectionPoint(1)-x).^2 + (e.IntersectionPoint(2)-y).^2);
% --- Do something
hold on
switch e.Button
case 1, col = 'r';
case 2, col = 'g';
case 3, col = 'b';
end
plot(x(i), y(i), '.', 'color', col);
i is the index of the clicked point, so x(i) and y(i) are the coordinates of the clicked point.
Amazingly enough, the mouse button which performed the action is stored in e.Button:
1: left click
2: middle click
3: right click
so you can play around with that too. Here is the result:
Best,
I have a 576x576x150 matrix. Each 576x576 set represents an image. When I want to plot one frame I do it by using the plot command:
figure(1);
imshow(B(:,:,45),[]) % plots frame 45
title('45') % tells frame number
However I would like to add a slider to the plot, so I can move from 1-150 frame within the figure.I've seen examples of people using uicontrol but I don't know how to code it. In addition to that, I would like to have a title on top of the figure telling me the frame number.
Here is how I do it. I like to keep a single function that does the plotting so you don't recycle commands elsewhere. You could replace the first two lines by function test(B) to use you own B matrix. This code is pretty easy to extend. You will also want to play with the layout to suit your purpose.
function test
B=rand(576,576,150);
fig=figure(100);
set(fig,'Name','Image','Toolbar','figure',...
'NumberTitle','off')
% Create an axes to plot in
axes('Position',[.15 .05 .7 .9]);
% sliders for epsilon and lambda
slider1_handle=uicontrol(fig,'Style','slider','Max',150,'Min',1,...
'Value',2,'SliderStep',[1/(150-1) 10/(150-1)],...
'Units','normalized','Position',[.02 .02 .14 .05]);
uicontrol(fig,'Style','text','Units','normalized','Position',[.02 .07 .14 .04],...
'String','Choose frame');
% Set up callbacks
vars=struct('slider1_handle',slider1_handle,'B',B);
set(slider1_handle,'Callback',{#slider1_callback,vars});
plotterfcn(vars)
% End of main file
% Callback subfunctions to support UI actions
function slider1_callback(~,~,vars)
% Run slider1 which controls value of epsilon
plotterfcn(vars)
function plotterfcn(vars)
% Plots the image
imshow(vars.B(:,:,get(vars.slider1_handle,'Value')));
title(num2str(get(vars.slider1_handle,'Value')));
The idea is to use uicontrol() to enable sliding/scrolling.
The following code is for scrolling (created by Evan Brooks, you can modify it to sliding):
function scrollfigdemo
% create new figure window
f = figure;
set(f,'doublebuffer', 'on', 'resize', 'off')
% set columns of plots
cols = 2;
% create 5 data sets to plot
x=0:1e-2:2*pi;
y{1}=sin(x);
y{2}=cos(x);
y{3}=tan(x);
y{4}=x.^2;
y{5}=x.^3;
% determine required rows of plots
rows = ceil(length(y)/cols);
% increase figure width for additional axes
fpos = get(gcf, 'position');
scrnsz = get(0, 'screensize');
fwidth = min([fpos(3)*cols, scrnsz(3)-20]);
fheight = fwidth/cols*.75; % maintain aspect ratio
set(gcf, 'position', [10 fpos(2) fwidth fheight])
% setup all axes
buf = .15/cols; % buffer between axes & between left edge of figure and axes
awidth = (1-buf*cols-.08/cols)/cols; % width of all axes
aidx = 1;
rowidx = 0;
while aidx <= length(y)
for i = 0:cols-1
if aidx+i <= length(y)
start = buf + buf*i + awidth*i;
apos{aidx+i} = [start 1-rowidx-.92 awidth .85];
a{aidx+i} = axes('position', apos{aidx+i});
end
end
rowidx = rowidx + 1; % increment row
aidx = aidx + cols; % increment index of axes
end
% make plots
axes(a{1}), plot(x,y{1}), title('sine'), xlabel('x'), ylabel('sin(x)')
axes(a{2}), plot(x,y{2}), title('cosine'), xlabel('x'), ylabel('cos(x)')
axes(a{3}), plot(x,y{3}), title('tangent'), xlabel('x'), ylabel('tan(x)')
axes(a{4}), plot(x,y{4}), title('x^2'), xlabel('x'), ylabel('x^2')
axes(a{5}), plot(x,y{5}), title('x^3'), xlabel('x'), ylabel('x^3')
% determine the position of the scrollbar & its limits
swidth = max([.03/cols, 16/scrnsz(3)]);
ypos = [1-swidth 0 swidth 1];
ymax = 0;
ymin = -1*(rows-1);
% build the callback that will be executed on scrolling
clbk = '';
for i = 1:length(a)
line = ['set(',num2str(a{i},'%.13f'),',''position'',[', ...
num2str(apos{i}(1)),' ',num2str(apos{i}(2)),'-get(gcbo,''value'') ', num2str(apos{i}(3)), ...
' ', num2str(apos{i}(4)),'])'];
if i ~= length(a)
line = [line,','];
end
clbk = [clbk,line];
end
% create the slider
uicontrol('style','slider', ...
'units','normalized','position',ypos, ...
'callback',clbk,'min',ymin,'max',ymax,'value',0);
Goal: To perform several clicks in one figure, containing an image displayed with imshow and save the coordinates of the "clicked" point(s), to be used in further operations.
Notes: I know about the functions getpts/ginput but I would like to perform this without using them. Is this possible using ButtonDownFcn? (see the following code)
function testClicks
img = ones(300); % image to display
h = imshow(img,'Parent',gca);
set(h,'ButtonDownFcn',{#ax_bdfcn});
function ax_bdfcn(varargin)
a = get(gca,'CurrentPoint');
x = a(1,1);
y = a(1,2);
At this stage the variables x and y only "live" inside ax_bdfcn.
How can I make them available in the testClicks function? Is this possible using ButtonDownFcn? Is this a good approach?
Thanks a lot.
EDIT1:
Thanks for the answer Shai. But I still cannot accomplish what I intended.
function [xArray, yArray] = testClicks()
img = ones(300); % image to display
h = imshow(img,'Parent',gca);
x = [];
y = [];
xArray = [];
yArray = [];
stop = 0;
while stop == 0;
set(h,'ButtonDownFcn',{#ax_bdfcn});
xArray = [xArray x];
yArray = [yArray y];
if length(xArray)>15
stop = 1;
end
end
function ax_bdfcn(varargin)
a = get(gca, 'CurrentPoint');
assignin('caller', 'x', a(1,1) );
assignin('caller', 'y', a(1,2) );
end
end % must have end for nested functions
This code (buggy!) is the closest I can get to what I want (after all the clicking, having an array with the x and y coordinates of the clicked points). I am clealy not understanding the mechanics for the implementation of this task. Any help?
There are several ways
Using nested functions
function testClicks
img = ones(300); % image to display
h = imshow(img,'Parent',gca);
set(h,'ButtonDownFcn',{#ax_bdfcn});
x = []; % define "scope" of x and y
y = [];
% call back as nested function
function ax_bdfcn(varargin)
a = get(gca,'CurrentPoint');
x = a(1,1); % set x and y at caller scope due to "nested"ness of function
y = a(1,2);
end % close nested function
end % must have end for nested functions
Using assignin
function ax_bdfcn(varargin)
a = get(gca, 'CurrentPoint');
assignin('caller', 'x', a(1) );
assignin('caller', 'y', a(2) );
Using 'UserData' property of figure handle
function ax_bdfcn(varargin)
a = get(gca, 'CurrentPoint');
set( gcf, 'UserData', a(1:2) );
'UserData' can be accessed (as long as the figure is alive) using cp = get( gcf, 'UserData');.
EDIT:
An example of a way to "communicate" the clicked locations to 'base' workspace
function ax_bdfcn(varargin)
a = get(gca,'CurrentPoint');
% the hard part - assign points to base
if evalin('base', 'exist(''xArray'',''var'')')
xArray = evalin('base','xArray');
else
xArray = [];
end
xArray = [xArray a(1)]; % add the point
assignin('base','xArray',xArray); % save to base
% do the same for yArray
After calling testClicks there are NO xArray or yArray variables in the workspace (at least there shouldn't). After the first click these two variables will "miraculously" be created. After every other click these two arrays will increase their size until you close the figure.