Let's say I have a .mat file and I know that each of the variables in it has XY in front of it (e.g. XYJanuary, XYFebruary, XYMarch and so on...) and I just want to remove the XY.
I have looked at this and tried to copy it but this adds the XY to my variable (XYXYJanuary, XYXYFebruay,...) but I want it to be just (January, Februay,...).
x= load('file.mat'); % Load into structure x
names=fieldnames(x); % names of the variables
for iname=1:length(names) % start the loop
x.(['XY', names{iname}]) = x.(names{iname}); % PROBLEM
x = rmfield(x, names{iname});
end
save ('newfile.mat', '-struct', 'x'); %save
x= load('file.mat'); % Load into structure x
names=fieldnames(x); % names of the variables
for iname=1:length(names) % start the loop
x.([names{iname}(3:end)]) = x.(names{iname}); % No more PROBLEM
x = rmfield(x, names{iname});
end
save ('newfile.mat', '-struct', 'x'); % save
You added the 'XY' to the LHS of your line, that makes it add it to the final solution. What I did is to chop off the first two entries, but keep the rest, hence the (3:end). This now works on a test case I created.
Related
I have code that uses Wolff's Algorithm to simulate the XY Model in MATLAB and I want to implement a pcolor/color map to demonstrate each spin according to their angles across the system. But I want it to be live and changing as the angles change.
Any idea how to do this?
This is an example of how I want it to look https://i.stack.imgur.com/aSp7s.png
If you save each snapshot of the lattice in a cell array A{t}, you can use the following function to view and save it as a video (if fileName is not empty, the function saves an mp4 video).
Another option is to adapt the function view_lattice to run your simulation (which, honestly, I wouldn't recommend, for performance issues). I will mark where you should edit for doing a "live" simulation
This is at least MATLAB R2019b (although it may be compatible with earlier versions, but no guarantee).
File view_lattice.m
function view_lattice(A,fileName)
% for a 'live' simulation, you will have to remove A from the input
% parameters and add the ones you need for the XY Wolff algorithm,
% which will be used to calculate each configuration A in the time loop below
% you will also need to remove the assert statements for 'live' simulation
%
% otherwise, you save snapshots from your simulation
% and use this function as is
%
% A -> A{k}[m,n] snapshot k containing the angles of spins in lattice site at row m and col n
% fileName -> if contains string, then records a video with the snapshots and name it with this string
assert(iscell(A) && all(cellfun(#(a)isnumeric(a) && ismatrix(a),A)),'A must be cell of numeric matrices');
assert(ischar(fileName),'fileName must be either an empty char or contain a file name');
recordVideo = ~isempty(fileName);
if recordVideo
vw = setup_video(fileName);
else
vw = [];
end
% setting some default axis properties to speed-up plotting
set(0,'DefaultAxesPlotBoxAspectRatio',[1 1 1],'DefaultAxesDataAspectRatioMode','manual','DefaultAxesDataAspectRatio',[1,1,1],'DefaultAxesNextPlot','replace');
fh = figure;
ax=axes;
for t = 1:numel(A) % for 'live' simulation, this loop should be the time loop
% here you calculate the new configuration A
% and call the function below with A instead of A{t}
vw = record_frame(vw,fh,ax,A{t},t,recordVideo);
end
% any video to close?
if recordVideo
vw.close();
end
end
function vw = record_frame(vw,fh,ax,A,t,recordVideo)
imagesc(ax,A);
title(ax,sprintf('snapshot %g',t)); % if you want, y
axis(ax,'square');
daspect(ax,[1,1,1]);
pause(0.01);
if recordVideo
vframe = getframe(fh);
vw.writeVideo(vframe);
end
end
function vw = setup_video(fileName)
vid_id = num2str(rand,'%.16g');
vid_id = vid_id(3:6);
vid_id = [fileName,'_',vid_id];
% Initialize video
vw = VideoWriter([vid_id,'.mp4'], 'MPEG-4'); %open video file
vw.Quality = 100;
vw.FrameRate = 16;
vw.open();
end
Test script: test.m
clearvars
close all
A = cell(1,30);
for t = 1:numel(A)
% creating a sequence of random snapshots only for illustration
A{t} = rand(20,20);
end
% viewing the animation and saving it as a video with name test
view_lattice(A,'test');
Output
%% I want to pass the values of char (here var_name{1})as that of double(here x) in histogram function. How can I do that?
% var_name could be much bigger
h={'h1','h2'}
var_name ={'x','y'}
time_step=100;
for i =1:time_step
x=%code that extract x from some data file %
y= %get y from some other file (actually using find command)
%the time loop will overwrite the x and y values
` for k=1:length(var_name)
%figure h
h{k}=histogram(var_name{k}) % I have been suggested to avoid eval %
%lot of procees to do here for every variable say x y than save the
%saveas(h{k},sprintf(...))
end
end
You have to use eval to evaluate the variable name, giving you the vector of data that variable contains:
histogram(eval(var_name{1}));
However, I'm guessing there's a better way to approach your problem, since using dynamically named variables is general not good practice.
Based on your updated example, one non-eval way you could do this is using structures and dynamic field names:
for i = 1:time_step
data.(var_name{1}) = % code that extract xs from some data file
data.(var_name{2}) = % get y from some other file (actually using find command)
for k = 1:length(var_name)
h{k} = histogram(data.(var_name{k}));
...
end
...
end
I want to make a matrix of scatterplots in Matlab (version R2014b), and have only two ticks (minimum and maximum) for each x and y axis because the real world example has more plots and that will be easier to read. Here is an example, and as you can see, the second for loop isn't working as intended to edit the ticks. Also, is there a way to set this without a for loop?
% Example data
example = [ -5.2844 5.0328 307.5500
-12.0310 5.1611 237.9000
-15.9510 7.5500 290.7600
-11.5500 13.6850 285.8400
-1.9356 9.4700 273.2600
-9.2622 4.7456 232.6000
-6.5639 5.2272 265.3800
-4.4795 14.8320 281.1300
-2.1474 13.0690 288.7300
-3.7342 11.7450 265.2200
-11.9040 10.9660 286.5700
-2.1789 6.7442 258.9700
-2.8316 11.8210 281.7500
-2.6170 7.4740 244.8600
-6.8770 1.6623 116.9800
-10.2210 5.7575 300.2200
-3.9430 5.9715 253.6000
-3.3690 5.6530 230.9700
2.6090 3.2750 236.8700
-5.1430 8.4060 273.9600
-7.9360 2.7855 254.8200
-2.8665 2.0241 176.0600
-0.0960 3.3165 228.6800
-8.8465 10.3240 289.2100
-8.1930 16.4070 289.7000
-6.5840 13.4010 283.2600
2.2405 8.4625 270.1000
-2.2505 7.5555 285.9100
-4.6955 6.2985 279.2000
-0.7610 12.5210 283.2000
-0.7510 9.9470 279.9100
1.7120 8.5990 285.5700
-0.6245 7.6905 251.9100
-19.2320 6.8545 306.2700
-4.1255 9.8265 298.2000
2.9486 3.8881 250.2100
1.7333 5.5000 240.7300
-6.5881 3.9152 234.3800
-7.9543 8.0771 276.8000
-6.9641 8.8573 284.2800
-10.3280 7.4768 291.8700
-8.0818 5.1250 250.6600
-10.1490 3.9427 271.0000
-2.7786 3.7673 213.6500
-14.5410 11.1500 288.9100
-6.8118 11.0210 280.2000
-2.6459 6.5127 213.2600
1.4036 4.2023 253.9400
-5.0014 9.3900 267.0600
-9.7382 12.0990 290.8800]
% Labels for data
data_labels = {'Variable1','Variable2',...
'Variable3'};
% Make scatterplot matrix with histogram on diagonal
figure()
[H,AX]= plotmatrix(example(:,:));
% label the axes of the plots (rotated) works fine
for i = 1:length(AX)
ylabel(AX(i,1),data_labels{i},'Rotation',0,'HorizontalAlignment','right',...
'FontSize',12);
xlabel(AX(end,i),data_labels{i},'Rotation',60,'HorizontalAlignment','right',...
'FontSize',12);
end
% Set ticks (not working yet)
NumTicks = 2;
for i = 1:length(AX)
L = get(AX(i,i),'XLim');
set(AX(i,i),'XTick',linspace(L(1),L(2),NumTicks));
% set y ticks here too
end
You are incorrectly using i or both subscripts when indexing into AX.
AX(i) % Rather than AX(i,i)
Also, it's better to use numel than length and use a variable rather than i as your loop variable (since that's a MATLAB built-in for 0 + 1i). Also, you can use a single linear index into AX rather than specifying row and column subscripts.
for k = 1:numel(AX)
L = get(AX(k),'XLim');
set(AX(k),'XTick',linspace(L(1),L(2),NumTicks));
end
If you want to do this witnout a loop, you could technically do it using cellfun and the fact that you can set the same property in multiple plot objects using the following syntax
set(array_of_plot_handles, {'Property'}, array_of_values_to_set)
So applied to your problem, it would be something like
% Get all XLims as a cell array
oldlims = get(AX, 'XLim');
% Compute the new xlims
newlims = cellfun(#(x)linspace(x(1), x(2), NumTicks), oldlims, 'UniformOutput', false);
% Now set the values
set(AX, {'XTick'}, newlims);
Or if you really want it to be one line
set(AX, {'XTick'}, cellfun(#(x)linspace(x(1),x(2),NumTicks), get(AX, 'Xlim'), 'UniformOutput', false))
I would like to know if some of you know of a way to automatically title plots with the name of the object plotted
so that for intance when I plot supermatrix(5:10,:,2:3)
the title (or the legend ..) on the plot says "supermatrix(5:10,:,2:3)"
thanks
Is this for debugging purposes? If not then I suggest you tell us your overall motivation because someone might be able to suggest a more robust method, but this might get you started:
vname = #(x)inputname(1); %//from here: https://www.mathworks.com/matlabcentral/newsreader/view_thread/251347
plot(supermatrix(5:10,:,2:3))
title(vname(supermatrix))
Although to be honest I cannot imagine why this would ever be useful
I think this does what you want and remains pretty flexible:
function h = plotwithtitle( plotstring, varargin )
argstoplot = evalin('caller', ['{', plotstring, '}']);
h = plot( argstoplot{:}, varargin{:} );
title(plotstring);
end
The following examples all work for me:
supermatrix=rand(10,10);
x=1:10;
y=rand(1,10);
plotwithtitle('supermatrix');
plotwithtitle('supermatrix(5:10,:)');
plotwithtitle('x, y');
plotwithtitle('x, y', '--r');
plotwithtitle('1:10', 'r');
plotwithtitle('rand(1,10)');
I've modified the function dfig originally created by F.Moisy for creating docked figures in order to have the command used for plotting show up in the figure name.
The idea is to read the last command in the command history and use that to generate the figure title.
function hh = dfig(varargin)
%DFIG Create docked figure window
% DFIG, by itself, creates a new docked figure window, and returns its
% handle.
%
% DFIG(H) makes H the current figure and docks it. If Figure H does not
% exist, and H is an integer, a new figure is created with handle H.
%
% DFIG(H, name, value,...) reads additional name-value pairs. See
% doc(figure) for available otions.
%
% DFIG will parse the command line input and use the text following dfig
% as figure name. E.g. calling dfig,plot(x(1:3),y(2:2:end)) results in
% the name "plot(x(1:3),y(2:2:end))"
% F. Moisy, moisy_at_fast.u-psud.fr
% Revision: 1.00, Date: 2007/09/11
% Modified (a lot) by Jonas
if nargin==0
h=figure; % create a new figure
else
% call figure with varargin
figure(varargin{:})
h = gcf;
end
if ~any(strcmp('name',varargin(1:2:end)))
% if no name has been supplied: try to use function call
javaHistory=com.mathworks.mlservices.MLCommandHistoryServices.getSessionHistory;
if ~isempty(javaHistory)
lastCommand = javaHistory(end).toCharArray';
funCall = regexp(lastCommand,'dfig\s*[,;]\s*(.*)$','tokens','once');
else
funCall = [];
end
if ~isempty(funCall)
if isnumeric(h)
set(h,'Name',[num2str(h),': ',funCall{1}],'NumberTitle','off')
else % HG2
h.Name = sprintf('%i: %s',h.Number,funCall{1});
h.NumberTitle = 'off';
end
end
end
set(h,'WindowStyle','docked'); % dock the figure
if nargout~=0 % returns the handle if requested
hh=h;
end
I'd like to save matrices which are input via GUI pushbuttons in a 3D matrix. for example: I click button 1 a 2-2 matrix is put in the first slice of the 3D matrix. I than click button 3 and a different 2-2 matrix is put in the second slice. SO on and so on. I hope this is clear enough. The problem I have is that I'm not an experienced programmer. I currently initialize a zeros matrix as follows in the opening func:
storageMatrix = ones(2,2,100);
setappdata(0, 'storageMatrix', storageMatrix);
I have put a function updateStorageMatrix in the main script like this, mind you this isn't finished yet.
function updateStorageMatrix
storageMatrix = getappdata(0, 'storageMatrix');
and than when I look at my code of pushbutton 1 for example it looks like this:
% --- Executes on button press in Add_Straightduct.
function Add_Straightduct_Callback(hObject, eventdata, handles)
%prompt command for k number and length
prompt = {'k0:','Length:'};
dlg_title = 'Straight Duct specs';
num_lines = 1;
SDelements = {'0','0'};
Straightduct = inputdlg(prompt,dlg_title,num_lines,SDelements)
%insert values in function
sizeStorageMatrix = size(getappdata(0,'storageMatrix')); %get size of the storage matrix
dimT = sizeStorageMatrix(1,3); %take the number of matrices
if dimT==1
straightDuct = straight_duct(str2num(SDelements{1}), str2num(SDelements{2}), Mach_Frange(1,1))
setappdata(handles.updateStorageMatrix,'storageMatrix', storageMatrix(1:2, 1:2, 1))=straight_duct(str2num(SDelements{1}), str2num(answer{2}), Mach_Frange(1,1))
dimT+1
else
setappdata(0,'storageMatrix', storageMatrix(1:2, 1:2, dimT+1))=straight_duct(str2num(SDelements{1}), str2num(answer{2}), Mach_Frange(1,1))
dimT+1
end
the straight_duct() is a function I used in the script when calculating the mufflers, I have several of those functions, I am not sure if that's the way to work when using GUI. I just hope you get the idea of what I'm trying to achieve and help me on my way. So I can actually make a UI for my script :)
This assumes you've initialized the storageMatrix elsewhere in the GUI like this...
handles.storageMatrix = zeros(2,2,100);
guidata(hObject,handles); % Must call this to save handles so other callbacks can access the new element "storageMatrix"
Then in your first button's callback...
% --- Executes on button press in Add_Straightduct.
function Add_Straightduct_Callback(hObject, eventdata, handles)
.
. % Whatever initializations you need to do
.
localStorageMatrix = handles.storageMatrix; %load the storageMatrix being used by other callbacks/functions
.
. % Whatever you need to do to generate the new 2x2 matrix "slice"
.
localStorageMatrix(:,:,end+1) = newSlice; % appends the new slice to the end of the, indexing using colons assumes newSlice is of the same first and second dimension as other slices in localStorageMatrix
handles.storageMatrix = localStorageMatrix; % overwrite the storageMatrix in handles with the contents of the new localStorageMatrix
guidata(hObject,handles); % save the handles struct again now that you've changed it
Alternatively, you could have just used the handles.storageMatrix throughout, without including a localStorageMatrix but I've included it for emphasis.