I was expecting that to work, but I am missing what is a "vector of handles", from MATLAB helpfile.
LEGEND(M), where M is a string matrix or cell array of strings, and
LEGEND(H,M) where H is a vector of handles to lines and patches also
works.
myone = ones(20,1);
mytwo = ones(20,1)+1;
rows = vertcat(myone,mytwo);
mylabels = {'Alpha', 'Beta'};
figure
grouplabels = mylabels(rows);
h = scatter3(rand(40,1),rand(40,1),rand(40,1),20,rows,'filled'), ...
view(-33,22)
legend(handle(h),grouplabels)
xlabel('X')
ylabel('Y')
zlabel('Z')
The problem with your code is that h, the output of scatter3, is a single handle. It's not an array of handles with the same size as your data (which is what you imply when trying to set 40x1 array of labels on it, ignoring irrelevant handle wrapper). And it's not even an array of two handles as one may have thought (one per color). So you cannot set legend like this. One way around would be to plot all the points of one color at a time:
hFig = figure();
axh = axes('Parent', hFig);
hold(axh, 'all');
h1 = scatter3(rand(20,1),rand(20,1),rand(20,1),20,'b','filled');
h2 = scatter3(rand(20,1),rand(20,1),rand(20,1),20,'r','filled');
view(axh, -33, 22);
grid(axh, 'on');
legend(axh, [h1,h2], {'Alpha', 'Beta'});
Related
My goal output is to have four plots displaying (time, dist_a), (time, speed_a), (time, dist_b), and (time, speed_b) when looping through a multidimensional array. However, I am displaying only 2 blanked plots.
Here is my code:
time = rand(10, 1)
dist_a = rand(10,1)
dist_b = rand(10,1)
speed_a = rand(10,1)
speed_b = rand(10,1)
dist = cat(2, dist_a, dist_b);
speed = cat(2, speed_a, speed_b);
for k = 1:2
figure;
plot(time, dist(k));
plot(time, speed(k));
end
Your problems were two-fold. Firstly, you were only plotting a single point as opposed to a vector, changing dist(k) to dist(:,k) for example fixes this. Secondly, if you want four figures with a loop that executes twice, you need to include another figure command before the second plot. The following should do what you asked for, I also added in some formatting to make the plots looks nicer
for k = 1:2
figure
plot(time, dist(:,k),'o','LineWidth',2);
xlabel('time')
ylabel('distance')
box on
grid on
figure
plot(time, speed(:,k),'o','LineWidth',2);
xlabel('time')
ylabel('speed')
box on
grid on
end
which gives:
I want to update a plot with multiple data lines/curves as fast as possible. I have seen some method for updating the plot like using:
h = plot(x,y);
set(h,'YDataSource','y')
set(h,'XDataSource','x')
refreshdata(h,'caller');
or
set(h,'XData',x,'YData',y);
For a single curve it works great, however I want to update not only one but multiple data curves. How can I do this?
If you create multiple plot objects with a single plot command, the handle returned by plot is actually an array of plot objects (one for each plot).
plots = plot(rand(2));
size(plots)
1 2
Because of this, you cannot simply assign another [2x2] matrix to the XData.
set(plots, 'XData', rand(2))
You could pass a cell array of new XData to the plots via the following syntax. This is only really convenient if you already have your new values in a cell array.
set(plots, {'XData'}, {rand(1,2); rand(1,2)})
The other options is to update each plot object individually with the new values. As far as doing this quickly, there really isn't much of a performance hit by not setting them all at once, because they will not actually be rendered until MATLAB is idle or you explicitly call drawnow.
X = rand(2);
Y = rand(2);
for k = 1:numel(plots)
set(plots(k), 'XData', X(k,:), 'YData', Y(k,:))
end
% Force the rendering *after* you update all data
drawnow
If you really want to use the XDataSource and YDataSource method that you have shown, you can actually do this, but you would need to specify a unique data source for each plot object.
% Do this when you create the plots
for k = 1:numel(plots)
set(plots(k), 'XDataSource', sprintf('X(%d,:)', k), ...
'YDataSource', sprintf('Y(%d,:)', k))
end
% Now update the plot data
X = rand(2);
Y = rand(2);
refreshdata(plots)
You can use drawnow:
%Creation of the vectors
x = 1:100;
y = rand(1,100);
%1st plot
h = plot(x,y);
pause(2);
%update y
y = rand(1,100);
set(h,'YData',y)
%update the plot.
drawnow
I have saved different Matlab plots in an unique .fig. The figure is like this:
Now, I would like to introduce a filter in these plots to reduce the noises, but unfortunately I have lost the code that generates these signals.
Is there a way to extract data of each signal in this figure?
I tried this:
open('ttc_delay1000.fig');
h = gcf; %current figure handle
axesObjs = get(h, 'Children'); %axes handles
dataObjs = get(axesObjs, 'Children'); %handles to low-level graphics objects in axes
objTypes = get(dataObjs, 'Type'); %type of low-level graphics object
xdata = get(dataObjs, 'XData'); %data from low-level grahics objects
ydata = get(dataObjs, 'YData');
But I am confused and I don't know if it's the right way to act.
Thanks!
A one-liner for your problem:
data = get(findobj(open('ttc_delay1000.fig'), 'Type','line'), {'XData','YData'});
The steps are there (from the inner calls to the outer calls):
open the file;
look into it for the line series;
return the data.
data{n,1} will contain the XData of the LineSeries number n, wile the data{n,2} will contain the YData of the said LineSeries.
If you want to smooth the lines directly in the figure, the idea is the same:
%//Prepare moving average filter of size N
N = 5;
f = #(x) filter(ones(1,N)/N, 1, x);
%//Smooth out the Y data of the LineSeries
hf = open('ttc_delay1000.fig');
for hl = transpose(findobj(hf,'Type','line'))
set(hl, 'YData', f(get(hl,'YData')));
end;
saveas(hf, 'ttc_delay1000_smooth.fig');
I have matrices x1, x2, ... containing variable number of row vectors.
I do successive plots
figure
hold all % or hold on
plot(x1')
plot(x2')
plot(x3')
Matlab or octave normally iterates through ColorOrder and plot each line in different color. But I want each plot command to start again with the first color in colororder, so in default case the first vector from matrix should be blue, second in green, third in red etc.
Unfortunately I cannot find any property related to the color index niether another method to reset it.
Starting from R2014b there's a simple way to restart your color order.
Insert this line every time you need to reset the color order.
set(gca,'ColorOrderIndex',1)
or
ax = gca;
ax.ColorOrderIndex = 1;
see:
http://au.mathworks.com/help/matlab/graphics_transition/why-are-plot-lines-different-colors.html
You can shift the original ColorOrder in current axes so that the new plot starts from the same color:
h=plot(x1');
set(gca, 'ColorOrder', circshift(get(gca, 'ColorOrder'), numel(h)))
plot(x2');
You can wrap it in a function:
function h=plotc(X, varargin)
h=plot(X, varargin{:});
set(gca, 'ColorOrder', circshift(get(gca, 'ColorOrder'), numel(h)));
if nargout==0,
clear h
end
end
and call
hold all
plotc(x1')
plotc(x2')
plotc(x3')
Define a function that intercepts the call to plot and sets 'ColorOrderIndex' to 1 before doing the actual plot.
function plot(varargin)
if strcmp(class(varargin{1}), 'matlab.graphics.axis.Axes')
h = varargin{1}; %// axes are specified
else
h = gca; %// axes are not specified: use current axes
end
set(h, 'ColorOrderIndex', 1) %// reset color index
builtin('plot', (varargin{:})) %// call builtin plot function
I have tested this in Matlab R2014b.
I found a link where a guy eventually solves this. He uses this code:
t = linspace(0,1,lineCount)';
s = 1/2 + zeros(lineCount,1);
v = 0.8*ones(lineCount,1);
lineColors = colormap(squeeze(hsv2rgb(t,s,v)))
ax=gca
ax.ColorOrder = lineColors;
Which should work for you assuming each of your matrices has the same number of lines. If they don't, then I have a feeling you're going to have to loop and plot each line separately using lineColors above to specify an RBG triple for the 'Color' linespec property of plot. So you could maybe use a function like this:
function h = plot_colors(X, lineCount, varargin)
%// For more control - move these four lines outside of the function and make replace lineCount as a parameter with lineColors
t = linspace(0,1,lineCount)'; %//'
s = 1/2 + zeros(lineCount,1);
v = 0.8*ones(lineCount,1);
lineColors = colormap(squeeze(hsv2rgb(t,s,v)));
for row = 1:size(X,1)
h = plot(X(row, :), 'Color', lineColors(row,:), varargin{:}); %// Assuming I've remembered how to use it correctly, varargin should mean you can still pass in all the normal plot parameters like line width and '-' etc
hold on;
end
end
where lineCount is the largest number of lines amongst your x matrices
If you want a slightly hacky, minimal lines-of-code approach perhaps you could plot an appropriate number of (0,0) dots at the end of each matrix plot to nudge your colourorder back to the beginning - it's like Mohsen Nosratinia's solution but less elegant...
Assuming there are seven colours to cycle through like in matlab you could do something like this
% number of colours in ColorOrder
nco = 7;
% plot matrix 1
plot(x1');
% work out how many empty plots are needed and plot them
nep = nco - mod(size(x1,1), nco); plot(zeros(nep,nep));
% plot matrix 2
plot(x2');
...
% cover up the coloured dots with a black one at the end
plot(0,0,'k');
so I'm processing a bunch of images at the one time, trying to display them all as figures with a series of plotted lines on each individual image as a result of the process. With some help I fixed the figure title issue, However the plotted lines are not appearing on my final figures, below is the code:
inputFolder = fullfile(pwd, 'BMPData');
filePattern = fullfile(inputFolder, '*.bmp');
%Get list of all Bmp Files in Folder
BmpFiles = dir(filePattern)
for i=1:length(BmpFiles)
fname = BmpFiles(i).name;
fullFileNameInput = fullfile(inputFolder,fname);
A = imread(fullFileNameInput);
%// Change
AR=A(:,:,1);
[rows, columns] = size(AR);
y1 = 200;
y2 = 315;
row1 = AR(y1, :); % Extract this line of gray levels from the image.
row2 = AR(y2, :);
figure('name',fname),imshow(A), hold on;
plot([0, columns], [y1, y1], '.b');
plot([0, columns], [y2, y2], '.m');
end
The reason I am doing this is because I want to mark 2 rows (200 and 315) on all my images and then do some statistical analysis on all the pixels in them rows for further processing techniques.
The reason why you're getting columns undefined is due to variable scope. When you define columns in SegmentationNew, columns is only available within the lifetime of SegmentationNew and only visible within SegmentationNew. Once SegmentationNew completes, column is no longer defined.
I honestly can't make heads or tails of what SegmentationNew is doing, but from the looks of it, there is no good reason why you should call it. All you need from it is y1 and y2, which are defined as constants. columns you can determine from the columns of the image. I'm also going to borrow from the duplicate post that Martin J.H. has linked to make naming the figure window more elegant.
To add to this post, your original code was plotting just the points. If you want to plot the lines as well, you need to remove the . characters from your plotting string for each call to plot. Specifically, change .b and .m to b and m respectively.
As such, do this:
for i=1:length(BmpFiles)
fname = BmpFiles(i).name;
fullFileNameInput = fullfile(inputFolder,fname);
A = imread(fullFileNameInput);
%// Change
columns = size(A,2);
y1 = 200;
y2 = 315;
figure('name',fname); %// Change
imshow(A); hold on;
plot([0, columns], [y1, y1], 'b'); hold on; %// Change
plot([0, columns], [y2, y2], 'm');
end