In Matlab functions can be started at events,but occasionally, like with the resize function, the events are called in rapid order and the function is called many times in succession, which can cause weird behavior and lag. Is there a way to have it listen for the event but only execute on the last event in a time range, e.g. .5 second?

I tried using a persistent variable that each one would update and it would only run if the variable still equaled what they set it to after .5 seconds, but this didn't work. Are there any clean ways to do this in Matlab or any language that I can steal ideas from?

edit: For example here is an implementation of the persistent variable method that I tried:

```
function practice
a = uipanel('ResizeFcn',@Delay,'Units','Normalized');
uicontrol(a)
end
function Delay(s,cb)
persistent a
if isempty(a)
a = 0;
end
a = a+1;
b = a;
pause(.1);
if b~=a
%disp(a-b)
else
%do work here
end
end
```

This method doesn't seem to work all the time, but that might just be because of the use of the magic number in pause(). It is also very unclear as to what it does without deep reading.

Answer:

The "weird behavior and lag" you see is almost always a result of callbacks interrupting each other's execution, and repeated unnecessary executions of the same callbacks piling up.

To avoid this, you can typically set the `Interruptible`

property of the control/component to `'off'`

instead of the default `'on'`

, and set the `BusyAction`

property to `'cancel'`

instead of the default `'queue'`

.

That won't solve all such issues (for example, you might have a callback that needs to respond to a live data feed that is just running too fast to keep up with), but for many situations it's the right approach. In particular for the situation of a `ResizeFcn`

callback, it will mean that the callback will only be called if it's not already running, and so stops any piling up of callbacks, and any effects of the same function running twice at once.

matlab,events,delay

In Matlab functions can be started at events,but occasionally, like with the resize function, the events are called in rapid order and the function is called many times in succession, which can cause weird behavior and lag. Is there a way to have it listen for the event but only...

matlab,matrix,multidimensional-array,scalar

I'm having problems multiplying specific values within my multidimensional matrix by a scalar. My matrix has the following dimension: size(comDatabe) = 5 10 3 397 10 The third dimension is an x-y-z coordinate frame. Something went wrong and now my y-axis is defined upside down for one subject (#8 out...

javascript,angularjs,events,angularjs-directive,angularjs-watch

I'm running into a bit of an issue solving a problem with some Angularjs functionality I'm working on. The basic idea is that I have a system where certain criteria must be met before the user is allowed to advance to the next section of the app. One example of...

matlab,filtering,convolution

I'm trying to design a Wiener filter in Matlab for a deconvolution problem but I'm having a lot of problems. I have a gaussian white noise process with a variance of 1.2 and a impulse response which has length two. Its values are g(0) = 5 and g(1) = 4....

multithreading,events

In a program I need to wait for an event (keypress) and get it's char. after that program will continue. this progress will Repeat several time. in my first try, codes run and any character did not save. I find out I should use threading but I am not Familiar...

javascript,jquery,events

I have an input box and a go button. When the user clicks the go button I want to compare the inserted value with another value. I am trying to acquire the input value inside a function like so function getInput(){ var entry =''; $('button.go').on('click',function(){ var entry = $(this).siblings('.input').val(); //return...

matlab,image-processing

I am trying to read all the images in the folder in MATLAB using this code flst=dir(str_Expfold); But it shows me output like this. which is not the sequence as i want. Can anyone please tell me how can i read all of them in sequence? for giving downmark, please...

matlab,system,equation

sorry if it already has a answer..i tried other links but it didn't understand i have 2 1*63 array .landa and v. each of their members are syms. and each v member is a function of all landa members.i have already calculated v members and they are all symbolic equations...

matlab,svm,auc

I'm having a weird problem in training an SVM with an RBF kernel in Matlab. The issue is that, when doing a grid search, using 10-fold cross-validation, for the C and Sigma values I always get AUC values equal to approximately .50 (varying between .48 and .54 depending) -- I...

matlab

my matlab version is 2012a. when I use fitcknn,has this error: Undefined function 'fitcknn' for input arguments of type 'cell'. how to calculate probability for each class for predicate with knn without fitcknn? after use this code, I want to calculate prob_estimates for each neighbors: knn = ClassificationKNN.fit(trainsample, trainlabel,'NumNeighbors',7); y...

matlab,time-frequency

Code tfr = abs ( tfr ); [row_size, column_size] = size(tfr); tfr = tfr(1:round(row_size/2), 1:row_size); surf(tfr); view(2); I get in R2014b of OSX 10.10.3 Yosemite but rotating around shows that the cells should not be black Why is the output black? I wonder if this is a hardware problem or...

matlab,machine-learning

This is my implementation of CostFunctionJ: function J = CostFunctionJ(X,y,theta) m = size(X,1); predictions = X*theta; sqrErrors =(predictions - y).^2; J = 1/(2*m)* sum(sqrErrors); But when I try to enter the command in MATLAB as: >> X = [1 1; 1 2; 1 3]; >> y = [1; 2; 3];...

arrays,matlab,matrix

I have matrix A and matrix B. Matrix A is 100*3. Matrix B is 10*3. I need to insert one row from matrix B each time in a sequence into matrix A after every 10th row. The result would be Matrix A with 110*3. How can I do this in...

matlab,plot

I have multiple 2D line plots in Matlab (they represent some wave moving through space). Each plot represents the wave at some time t. I want to animate through these plots (i.e. show the first plot for a fraction of a second, then show the next one, and the next,...

c++,matlab

Is there an alternative way to call a C++ class using MATLAB, and operate its methods on MATLAB variables?

matlab,loops,for-loop,while-loop,do-while

This is my one dimensional array A. containing 10 numbers A = [-8.92100000000000 10.6100000000000 1.33300000000000 ... -2.57400000000000 -4.52700000000000 9.63300000000000 ... 4.26200000000000 16.9580000000000 8.16900000000000 4.75100000000000]; I want the loop to go through like this; (calculating mean interval wise) - Interval length of 2,4,8 (a(1)+a(2))/2 - value stored in one block of...

matlab,plot,legend,movie

i have a question regarding legend for movies. This is my code: fig = figure(); for i = 1: 70000 plot(signal1) hold on; plot([i,i],[-5,5]) plot(signal2,'r') hold off; title('\fontsize{14} my data'); legend('signal1','signal2'); axis tight; f(i) = getframe(fig); end The legend shows the same colors for the first two things I plot....

string,matlab

I have a string "FDFACCFFFBDCGGHBBCFGE" . Could anyone help me to generate a new string with the same order but no element inside repeated twice. Thanks ! The expected output should be like this : "FDACBGHE"...

events,webview,event-handling,windows-phone,handler

Which callback/delegate is the one to intercept the event of a user clicking on a link within a WebView? I'd want that URL. I just need to know if it is possible and how should I do in some way.

excel,matlab,cluster-analysis,k-means,geo

I have 8 traveling consultants that need to visit 155 groups across the continental united states. Is there a way to find the optimal 8 regions based of drive time using k-means clustering? I see there are some methods implemented already for other data sets, but they are not based...

arrays,matlab

I have two vectors, one of them stores the width dimension of a set of images and another one the height of these set of images. I want to use these values as two dimensional vectors [width height] and store them in a matrix. The first line, for instance, keeps...

javascript,google-maps,events,infowindow

Here is a sample google map with three polygons. I am setting the infowindow for each polygon as, for (var i in coordinates) { arr = []; for (var j=0; j < coordinates[i].length; j++) { arr.push( new google.maps.LatLng( parseFloat(coordinates[i][j][0]), parseFloat(coordinates[i][j][1]) )); bounds.extend(arr[arr.length-1]) } // Construct the polygon. polygons.push(new google.maps.Polygon({ paths:...

c#,events,design

I am refactoring some old code, where I have a lot of static events like this public static event Action Updated; public static void OnUpdated() { if (Updated != null) Updated(); } I found out what using lazy singletons is often better than using static classes: no memory is consumed...

matlab,matrix,least-squares

How can I solve , where and and in the least squares sense in matlab? So I'd like to have the minimizing as output....

matlab,distribution,sampling,random-sample

How can I create a vector x in Matlab that has values between 0.8 and 1.2, randomly sampled from a: 1. Uniform 2. Normal distribution? There are a lot of functions dealing with distributions, but I'm having trouble using them properly....

matlab

A text file could be loaded as below: load sourceETA/Record1/result1.txt How can I use a variable in address of loading? For example (n is a variable): [load 'sourceETA/Record1/result',num2str(n),'.txt'] But the above code doesn't work! How do I do?...

matlab

So, I want to be able to look at (read: copy) MATLAB's NonLinearModel method of printing the regression results to the screen such as this. Nonlinear regression model: y ~ (alpha1 - alpha2*t^0.5) Estimated Coefficients: Estimate SE tStat pValue alpha1 1.0253 0.0082253 124.66 4.8823e-24 alpha2 0.0061783 0.00073277 8.4314 4.4834e-07 Number...

matlab,plot

I want to display three figures in a figure window. Assuming that I divide 2x2 regions. subplot(2,2,1) ---------+----------- | R1 | R2 | ---------+----------- | R3 | R4 | ---------+----------- I want to show a figure merging R1 and R3 ant other two in R2 and R4 I can display...

matlab,simulink

I am working on a simple System Object in Matlab/Simulink. It looks like this : classdef realtime_header_detectorSO < matlab.System & matlab.system.mixin.Propagates % correlateHeader % % This template includes the minimum set of functions required % to define a System object with discrete state. properties Header %nrOfBitsInPreviousStep=0; s=100; d=zeros(1,s); end properties...

matlab

What is the ellipsis for in this Matlab statement? frame = insertObjectAnnotation(frame, 'rectangle', ... bboxes, labels); ...I could not find in their online doc....

matlab,image-processing

I have a binary matrix containing several binary objects and I want to bridge between them. Actually I have the following picture: And the result has to be like this: Is there any function or a shortcut way, other than loops, for this problem?...

matlab,cell

I'm trying to equate each element to an array which correspond to cell element. To explain it more precisely, e.g A = {[1 1 1], [0 0 0 0 0], [1 1],[0 0 0 0 0]}; B = [0 1 0 0]; So the thing I want is : A=...

c,matlab,fopen,mex

I have a little experience with Matlab, but am new to the mex environment. What I am trying to do is to save some values I compute to a txt file in my C routine. For the sake of simplicity I am using the example arrayProduct.c from MathWork's Create C...

matlab,matlab-figure

I'm struggling to plot multiple functions on one figure. Here is the code that I have: syms t a; a=0.9514; F1=0.5*sqrt(3*t^2); F2=-0.28375*t^2+1.155*a*(t-a)+1; F3=1; E1=diff(F1,t); E2=diff(F2,t); E3=diff(F3,t); I want to plot E1, E2 and E3, each only within a certain range, to make a "composite" line. I've tried plotting with ezplot...

matlab,plot,signals,circle

I have some random signal (for example sin signal) with the time scale. t=0:0.1:2*pi y=sin(t) plot(t,y) Now I want to draw this signal on this circle. So the time vector actually becomes an envelope of the circle. Envelope of the circle represents "y = 0" in cartesian coordinate system. Here...

matlab,regression

I am doing some bone segmentation whereas the result of this segmentation is points placed in a circular pattern around this bone. However as it is taken using a qCT scan, there is quite a lot noise (from e.g. flesh) on the points that i have. So the overall problem...

image,matlab,image-processing,image-segmentation

I have an image which I want to divide into overlapping blocks. I have set the box to be of size 8 rows and 8 columns, and the overlapping factor to be 4 rows/columns. This is what I have written to solve this: img = imread('a03-017-05.png'); overlap = 4 count...

delphi,events,components

I am developing a DataAware component and executing some code after the database is open. This is the code I have at the moment: TMyDataAwareComponent = class(TDataAwareComponent) private { Private declarations } procedure ToBeExecutedOnAfterOpen(DataSet: TDataSet); protected { Protected declarations } public { Public declarations } constructor Create(AOwner: TComponent); override; end;...

php,events,laravel,domain-driven-design,dispatcher

When i need to raise domain events, should i use framework specific Event Dispatcher or create my own Event Dispatcher that implemented by framework event dispatcher ? Since the framework has a really nice event dispatcher and the term of DDD said the domain layer should not dependent on any...

matlab,plot

I have a semilogarithmic plot which works so far with semilogx. Now I would like to change the tick labels. Now it says 10^8 10^9 ... 10^13, but I would like to see 1e8, 1e9, ... 1e13 on the x-axis. How can I change that? Cheers Manuel...

image,matlab,image-processing,computer-vision

I need to save a set of pre-processing images in matlab, resulting in grayscale images. The problem is the fact that these pre-processed images have pixel values higher than 255. If I save them with imwrite() as, for instance, .PNG files, does matlab normalize the values to be in [0,255]...

image,matlab,image-processing,mask,boundary

I'm trying to create a mask (or similar result) in order to erase pieces of a binary image that are not attached to the object surrounded by the boundary. I saw this thread (http://www.mathworks.com/matlabcentral/answers/120579-converting-boundary-to-mask) to do this from bwboundaries, but I'm having trouble making suitable changes to it. My goal...

matlab,image-processing

I have a labeled matrix containing two objects. How can I thicken an object to a curve? Actually I have the following image: and I want this: Each pixel of the resulting curve is the median of each column. But if you have another idea, it is acceptable, because I...

matlab

Is it possible to add statements in between the codes. For example: If I have a code like this, r(:,1) = a(:,1) - a(:,2); Then can I write it as, r(:,1) = a(:,1)("this is a constant") - a(:,2)("this is a variable"); ...

matlab,polynomial-math

I have the following code: syms z Gc=1.582*(1-0.3679*z^-1)/(1+.418*z^-1); Ghp=.3679*(z^-1)*(1+.718*z^-1)/((1-z^-1)*(1-.3679*z^-1)); T=(Gc*Ghp)/(1+Gc*Ghp); clipboard('copy', latex(simplifyFraction(T))); Which results in following for T: How can I normalise coefficients? I.e. I want the z2 in denominator and z in numerator to have the coefficient of 1. Is there any function in Matlab to do so?...

matlab,typeconverter

I'm currently using a MATLAB to work and I need some help: I need to convert my output data (variable: units) be a double instead of a cell because I must perform a sum: units = inputdlg(question,title); sum = units + i; I've tried this code also but didn't solve...

matlab

I have 20 column vectors in the workspace and I'd like them all to be contained within a cell array. They're all labelled data1, data2, data3,...data20. Is there a faster way to do this than: cell = {data1, data2, data3, data4, data5, data6, ...} all the way up to data20?...

string,matlab,filenames

I am using the below mentioned code to get the file names of images according to their id's from images_1 text file as strings and use them to read the images from their directory image_count=1; for image_count=1:6 file=fopen('D:\Academics\New folder\CUB_200_2011\images_1.txt','r'); C = textscan(file, '%s'); original_image=imread('D:\Academics\New folder\CUB_200_2011\images\%s','C{1}{2*(image_count)}'); imshow(original_image) end I am able...

matlab,matrix

I have a matrix looks like: 0 0 0 0 0 1 0 0 0 0 0 2 0 0 0 0 0 2 0 0 0 0 0 1 0 1 0 0 0 1 0 4 0 0 0 0 0 3 0 0 6 0 0 4...