FAQ Database Discussion Community

## Stein-haff shrinkage formula in MATLAB

matlab
I have a data matrix X of size p*n where p=10 and n=30. Assume the covariance matrix S = XX'/n and its eigenvalues by the vector l. I want to compute this formula in MATLAB: I began by writing the code but I don't know how to write the sum...

## function wait to execute

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 plots as movie with legend

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....

## MATLAB - How to merge figure sections vertically

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...

## how to detect partial corrupted images in Jpg/Jpeg format

matlab,image-processing
In a very big image dataset, we have some corrupted images as following images. These images can be viewed without any problem, but human eyes can see some corrupted areas in gray color. How can I detect these corrupted images？ Actually I have written a script in Matlab for detecting....

## MATLAB: How to make camera light follow 3D Rotation

matlab,user-interface,3d,rotation,lighting
I have come into a problem recently when trying to rotate 3D objects. I am building a GUI and I have a separate figure where an object is plotted. In the figure, I allow the user to use MATLAB's built-in rotate button to move the object around. However, I am...

## Skip data files while reading input and writing output in matlab code

matlab
I use matlab code to read several files and write output in the following way: n=202; for idx = 0:n infilename = sprintf('pt%d.txt',idx); outname = sprintf('out%d.txt',idx); Now if some arbitrary data files are missing e.g. pt20.txt, pt50.txt ,etc then the code is terminated. I would like to modify the code...

## Constrained high order polynomial regression

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...

## Matlab: Input Directly a Matrix into a Cell from an Address

matlab
How could I input directly a matrix into a cell that has been loaded from an address? For example, if Response is defined as a cell: Response(1,1)={load (['sourceETA/Tn',num2str(period*10),'/ETdisp.txt'])}; But the above code doesn't work! How do I do?!...

## Matlab Calculating mean of distribution quantile in a for-loop

matlab,loops,for-loop,distribution,quantile
I am trying to calculate portfolio cVaR (conditional value at risk) levels from my simulated data for various portfolios. I am able to do that for one single portfolio using the following code: % Without a for-loop for series 1 test2 = test(:,1) VaR_Calib_EVT = 100 * quantile(test2, VarLevel_Calib); help1...

## Matlab: What are the ways to determine the distribution of the data

matlab,statistics,distribution
I have a data set of n = 1000 realizations of a random variable X and is univariate -- X = {x1, x2,...,xn}. Data is generated by varying a parameter on which the random variable depends. For example, let the r.v be Area of a circle. So, by varying the...

## Matlab - Multiply specific entries by a scalar in multidimensional matrix

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...

## MATLAB Access Classreg

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...

## complexity of generating a sparse matrix

r,matlab,matrix,sparse-matrix
I have a symmetric matrix S(n*n) where approximately 70% of the data are 0. Symmetric matrix I want to convert the symmetric matrix into a sparse matrix with t rows. What would be the time complexity of generating a sparse matrix from the original symmetric matrix? Is it O(n^2), because...

## Why do I have a decimal error when writing data to MS Access via Matlab?

matlab,ms-access,rounding,numeric
I write numeric data to MS Access tables. All the tables have the same numeric fields format (ie 'real simple', 'standard', 'auto'). I push numbers via Matlab in the tables and MS Access rounds numbers to the 1rst decimal and i can't modify it. Does someone know ? Screenshots there...

## Looking for a way to plot angle and distance on a semi circle (MATLAB)

matlab
I have a bunch of angle data ranging from 0 to 180 degrees, along with an equal amount of distances ranging from 0 to 15 meters. I'm looking for a way to get a semi circle (like the top half of a rose plot) where for each data point I...

## Matlab: Writing to a file

arrays,matlab,loops,math,for-loop
I want to store mean_2....mean_8, std_2....std_8, and coVariance as separate columns in a file. Help Please? This Code calculates IntervalFeatures of Erp signal with 256 time frames and plots them Datapoints are store in A ___________HowTheCodeWorks________________________________________________ each 1x4 sliding sub-matrix is made a column for eg:- if A is...

## MATLAB. Overlay plotted lines onto an existing .avi movie

matlab,avi
I would like to plot series of known coordinates as lines onto a figure of known width and height. Then import a .avi movie of the same height and width, and then combine these two so that the lines overlay the video. I've been looking around google and stackoverflow, but...

## Computing time complexity of the sparse matrix (2)

r,matlab,matrix,sparse-matrix
I have a data set (D) of (nxd) where n=number of rows and d= number of dimensions, I create a similarity matrix (S)(nxn) by comparing each row of the data set (D) and then convert it into a sparse matrix (tx3) where t is the number of non-zero elements of...

## How to create structure in MATLAB with many repeated substructures in an efficient way?

matlab,data-structures
I need to create a structure in MATLAB which is like this: under the main struct there are 3 sub-structures: Left, Right, Center. Under Left and Right there are 18 sub-structures each (A,B,C,D,E,...), and under Center there are 5 sub-structures. Under each of the 18 and 5 sub-structures I have...

## solve symbolic system of equations inside an array

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 equating cell elements to array

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=...

## Is there a shortcut key to comment multiple lines in matlab editor

matlab,editor
Is there a shortcut to comment multiple lines in matlab. If there isn't can I create one?

## How to force my output data in a inputdlg on Matlab be a double?

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...

## xcorr function with impulse response

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....

## Generate random binary sequence with a specific ratio

arrays,matlab,random
I want to generate a random binary sequence with a ratio of 50%, that is, the same amounts of 0s and 1s. This is what I have so far: length_sequence = 1000; ratio = 0.5; A = logical(randi([0 1],length_sequence,1)); The only problem is that I dont know how to set...

## Representing bars with different colors in matlab

matlab,bar-chart
i have a bar graph having three bars as follows x=[0.22,0.34,0.42] bar(x,0.1,'stacked') somenames={'IND Relation' ; 'DIS Relation' ; 'EQ Relation'} set(gca,'xticklabel',somenames) ylabel('F1') all the three bars are in blue color but i want to represent IND Relation with Brown color, DIS Relation with green color and EQ Relation with blue...

## Can we add a statement in between MATLAB codes?

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"); ...

## Logic of this FWHM script?

matlab
Could someone explain the logic of this program. I dont understand why the y=y/max(y) and, interp = (0.5-y(i-1)) / (y(i)-y(i-1)); tlead = x(i-1) + interp*(x(i)-x(i-1)); The script: function width = fwhm(x,y) y = y / max(y); N = length(y); MicroscopeMag=10; PixelWidth=7.8; % Pixel Pitch is 7.8 Microns. %------- find index...

## Matlab: Looping through an array

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...

## Plot multiple functions on one figure

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...

## A function to calculate cumulative maximum for a double matrix in MATLAB

matlab,function,matrix,max
Is there any function that can calculate cumulative maximum for a double matrix? I have a 1*3000 matrix and I need to calculate the cumulative maximum. For example if the matrix is: A = [8 3 6 7 9 10 6 2 2 3] The cumulative maximum array will be:...

## How to solve for matrix in Matlab?

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....

## Animate through multiple 2D Matlab plots

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,...

## How to normalise polynomial coefficients in a fraction?

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?...

## Passing parameters to a Matlab function

matlab
I have a very simple question, but I didn't figure out how to solve this.I have the function definition below: function model = oasis(data, class_labels, parms) % model = oasis(data, class_labels, parms) % % Code version 1.3 May 2011 Fixed random seed setting % Code version 1.2 May 2011 added...

## What is the right way to add function handles recursive and see the right output after printing it?

matlab
This is what I tried: f = @(x) 0; for i = 1:n f = @(x) f(x) + x^i; end It seems to do the right thing, when I test it by putting in some values. But when print f I got this output f = @(x) f(x) + x^i...

## MATLAB - How to change “Validation Check” count

matlab,neural-network
How can I change "Validation Checks" value from 6 to higher or lower values using code? I have following code: % Create a Pattern Recognition Network hiddenLayerSize = ns; net = patternnet(hiddenLayerSize); net.divideParam.trainRatio = trRa/100; net.divideParam.valRatio = vaRa/100; net.divideParam.testRatio = teRa/100; % Train the Network [net,tr] = train(net,inputs,targets); % Test...

## Giving a string variable as a filename in matlab

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...

## Reading all the files in sequence in MATLAB

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...

## Plotting random signal on circle

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...

## imread function doesn't work in matlab

matlab,image-processing,matlab-figure
I am new to Image processing and learning matlab. Actually till now I have used matlab cloud version where uploading an image was directly possible and didn't face any issue. But now I am facing an extreme problem of uploading an image in matlab offline version software. I imported an...

## thicken an object of image to a curve in matlab

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...

## How to access variables in the properties block of a Matlab System Object?

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...

## Display a table in MATLAB

matlab,formatting
I am trying to display a table with two columns and 86 rows. Instead of outputting the rows, the size is stated. Is there a way to change this? I am new to MATLAB and am coming from a background in C/C++ so I may just be approaching this all...

## How to concatenate 3 histograms on the same graph in Matlab

matlab,image-processing,plot,histogram
I have calculated 3 histograms for an rgb image using imhist function in Matlab, one for each channel. I want to plot these histograms on the same graph, where for instance, the histogram for the first (red) channel stretches on the x axis from 0 to 255, the histogram for...

## Visually midway between two points on a x axis log scale [closed]

matlab,math
The follow plot shows my question: I would like to add a line between the points of 1e-1 and 1e-2. So I thought just (1e-1+1e-2)/2. But for a log scale that is not "midway". How can I calculate the "visual" midway value between these, or any two points in this...

## Matrix naming on loop

matlab,octave
I'm writing a piece of code where I can define a number of matrices that will be generated and then a loop generates them. The piece where I'm struggling is on the "naming" of the matrices, since I want to name as follows: matrix1; matrix2; etc. The code below is...

## Fastest way to copy some rows from one matrix to another in OpenCV

c++,matlab,opencv,matrix
I have a [32678 x 10] matrix (w2c) and I want to copy 24700 rows of it to another matrix(out). I have the index of the rows to be copied in a vector(index). For doing this in matlab I do: out = w2c(index_im,:); It takes approximately 0.002622 seconds. In OpenCV:...

## How to return an array with unhappy numbers removed?

matlab,function
I'm quite new to using MATLAB, and am still trying to understand how to make this particular function. I understand the formula for performing this on paper, but I'm having trouble translating it into the required MATLAB syntax. How would a function be written such that it takes an array...

## two dimensional unique values in Matlab

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...

## Insert elements to the matrix using index

arrays,matlab
I would like to add the elements to the array using their index. array_in = [1 5 6 8 9]; index = [2 4]; newElements = [25 67]; index = index + (0:length(index)-1); expected output: array_out = [1 25 5 6 67 8 9]; 1.using for loop: tmp = array_in;...

## Summing rows at a fixed distance in Matlab?

matlab
I have the following matrix A in Matlab of dimension (m*d)x2 A=[1 1; 3 2; 8 3; ----- 9 1; 2 2; 5 3; ----- 6 1; 1 2; 4 3; ----- 8 1; 1 2; 5 3]; Hence m=max(A(:,2))=3 and d=4 is the number of submatrices in A of...

## Does Matlab support function-objects?

matlab,function-object
Trying to figure out if I have access to function object programming techniques for use in our Matlab scripts. This would be analogous to .NET's Func type, or Python's function objects. Does Matlab give functions first class object status?

## Create mask from bwtraceboundary in Matlab

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...

## free() and mxFree() in MATLAB - freeing memory twice

matlab,memory-management,free,mex
Good day, I have the following code which has given me problems for a day already. I have debugged it, and it works fine until trying to free the memory. The free() function should be called at the end of the execution automatically, so I commented the mxFree() code out,...

## Inserting One Row Each Time in a Sequence from Matrix into Another Matrix After Every nth Row in Matlab

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...

## how to calculate probability for each class for predicate with knn without fitcknn?

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
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?...

## Connecting two binary objects in matlab

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 - object orientated with abstract Interface - How creating object?

matlab,object
Hello lovely community, i am quite new here, but still hope someone can help me out. I just worked a bit with Matlab in the past and want to do a new project. Earlier I just stored all in one Matlab file and didn't had the need to use classes....

## what does ellipsis mean in a Matlab function's argument list?

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

## K-Means Clustering a list of US addresses based on drive time

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...

## Read data only when it is present

matlab,data,serial-port,fscanf
I try to read data from the COM3 port. I'm using : in = fscanf(s); if(in == 'A') fclose(s); break; end The problem is, when no data is send to the com3 port, the fscanf line will wait for a certain time and than give a timeout. Is there a...

## Create string without repeating the same element jn the string (Matlab)

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"...

## Operating a C++ class from Matlab without mex [closed]

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

## Matlab - plot bar and line graph on the same y axis

matlab,plot,line
I'm trying to plot a line graph and a bar graph on the same y-axis: figure; plotyy(Pert, Rfootvel(:,i+1), Pert, 0,'bar','plot'); hold(ax(1), 'on'); legend('Pert 1-8', 'Base'); ylim(ax(2), [0 1]); title(['The avg pert velocity of the first step vs the avg base velocity, PP' num2str(j)]); Unfortunately, setting the second y-axis limit like...

## using statset for changing the properties in matlab

matlab,factor-analysis
Trying to change the optimopts properties of the factoran function, namely, TolX and TolFun in Matlab but apparently the values are still remaining as the default: optionsFactoran = statset('TolX',1e-4,'TolFun',1e-4) and then using the factor analysis function: [lambda,psi,T,stats,F] = factoran(MyMatrix,10,'optimopts',optionsFactoran); as can be seen here, the values are still the default:...

## Sum of n-1 columns of a double matrix in MATLAB

matlab,matrix
I have a 1*3000 double matrix. I am doing some calculation and I need to calculate sum of n-1 columns in each step. For example, if I have this matrix: A = [1 2 3 4 5 6] The summation I'm looking for should be like this: B = [0...

## Matlab Distribution Sampling

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 removing rows which has duplicates in sequence

arrays,matlab,matrix
I'm trying to remove the rows which has duplicates in sequence. I have only 2 possible values which are 0 and 1. I have nXm which n shows possible number of bits and m is not important for my question. My goal is to find an matrix which is nX(m-a)....

## Indicate name of filled areas inside area plot - Matlab?

matlab,matlab-figure
It's difficult to identify in this area plot each one of the many filled areas by just looking at the legend (it's like 16!). So, I was wondering if there's a way to place some sort of labels (with a pointer perhaps?) inside the plot that clearly identifies each filled...

## Creating a cell array of workspace variables without manually writing them all out. MATLAB

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?...

## How to get varargout to output text from pushbuttons in Matlab GUI?

matlab,matlab-guide
I am trying to create a GUI using GUIDE where it allows the user to pick one of two pushbuttons. The strings in the pushbuttons will vary each time (I haven't automated this yet), but when any of the pushbuttons is pushed, I'd like the GUI to put out the...

## Detecting if ranges overlap - MATLAB

matlab
I have a script which aims to detect of gaps between genes along chromosomes, the coordinates of these gaps and assign a category to the gap. It takes an input file in this format: Chr start finish dir chrI 335 649 + chrI 538 792 + chrI 1807 2169 -...

## Matlab — SVM — All Majority Class Predictions with Same Score and AUC = .50

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...

## Join matrices with same values in different vectors in MATLAB

matlab,matrix,merge
I am trying to merge two matrices that share same values in multiple columns. The following matrices should exemplify my problem and provide a MWE. However, my data is very long size(500000, 4), therefore I am searching an efficient way to merge them. The data consists of option data where...

## MATLAB, extracting and saving values in a vector between 0 and 5, then 5 and 10, and so on

matlab
I have a column vector of values between 0 and 180. I'm looking for a way to extract all the values as columns between 0 and 5, then all the values between 5 and 10 and so on up to 180, and then save all these into a cell array....

## Adding data in intervals in Matlab

matlab
Hi I have data in MATLAB like this: F = 1.0000 1.0000 2.0000 1.0000 3.0000 1.0000 3.1416 9.0000 4.0000 1.0000 5.0000 1.0000 6.0000 1.0000 6.2832 9.0000 7.0000 1.0000 8.0000 1.0000 9.0000 1.0000 9.4248 9.0000 10.0000 1.0000 I am looking for a way to sum the data in specific intervals. Example...

## Why black surf from this Matlab command?

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...

## How to switch Matlab plot tick labels to scientific form?

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...

## Trying to draw lines from the origin to coordinates in 2D (MATLAB)

matlab
I'm trying to have 3 lines come out from the centre of the graph at x = 0, going to the coordinates marked by the black dots. I got the black dots using scatter(X,Y); but can't find a way to have lines emanating from the origin to these dots....

## Getting time frequency of number in array in Python?

python,arrays,matlab,numpy
Let's say I have a time series represented in a numpy array, where every 3 seconds, I get a data point. It looks something like this (but with many more data points): z = np.array([1, 2, 1, 2.2, 3, 4.4, 1, 1.2, 2, 3, 2.1, 1.2, 5, 0.5]) I want...

## Randomly select Elements of 4D matrix in Matlab

matlab,matrix,random,4d
I have a 4D matrix with dimensions 7x4x24x10 (Lets call it main_mat). I want to get a matrix of size 7x4x24 (rand_mat) so that each element of this (rand_mat) matrix is actually a uniformly random draw from the main matrix (main_mat). I am sorry if I have not put the...

## summing matrix columns based on another matrix

matlab
I have two matrices of the same size. First matrix: weights 800 x 1250 Second matrix: country_code 800 x 1250 Each column is an observation. What I would like to do is sum each column in the weights matrix based on the country_code. An example below might explain it better...

## Shift Plot Data Along X Axis Matlab

matlab,plot,axis,shift
I cannot get Matlab to plot a a second time series to specific points along the x axis. My data are two time series. Time series A is a 5 X 1 and time series B is a 7 X 1. I need A to plot on xticklabels 1-5. Then,...

## Append legends. Whats wrong with my code?

matlab
I'm trying to add legends the plot when it adds a curve. I can't see whats wrong with my code, can someone please help? I'm using matlab r2015a on ubuntu. x=1:5; v=1:5; plot(x,v) [~,~,plots,str] = legend('1'); hold on for i=4:10 pl=plot(x,v*i); [~,~,plots,str]=legend([plots;pl],str,num2str(i)) end when i run it i get: plots...

## Matlab Crahes upon fopen in Mex File

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...

## How to prevent exceeding matrix dimensions while dividing an image into blocks?

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...

## Saving images with more than 8 bits per pixel in matlab

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]...

## Why can't I calculate CostFunction J

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];...

## Matlab: For loop with window array

arrays,matlab,math,for-loop,while-loop
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...

## Can I use two separate ODE call functions for a system of two differential equations in MatLab?

matlab,ode
I am trying to code a system of ODE's shown below. As seen, the second ODE completely depends on the value of the first ODE. How can I code the second ode? I am using ode45....

## How to export fitted curve to 1D vector

matlab
With the use of Curve Fitting toolbox I'm fitting to 11 data points a curve described by a custom equation. As a result I get something like this: I want to save 1D vector represented bye the red line on the plot above into a matlab variable. I try to...

## Double integration using experimental data

matlab,data,integration,splines
I need to perform a double integration using experimental data, but my integration limits are the same for each integral, in this case, the time. Mathematically I need to calculate: E [ a0+ ∫0T a(t)dt ] = a + limTx → ∞ (1/T) ∫0T ∫0t a dt dT After some...

## Interpolation inside a matrix. Matlab

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...

## Putting space between bars using bar function

matlab,plot,bar-chart
I am try to plot 16 bars, 8 of these belong to one group. I want to give this group the red color, the other 8 belong to another group which is given the blue color. I would like to arrange the bar in pairs, each pair containing one from...

## Matlab creating mat files which names are written in the variable

matlab
I have a variable 'b'. Inside of b, I have 27X1 cell. In every cell there is some characters for example in 1x1 there is asdf, in 2x1 there is dfgh it's going on like this. I want that matlab creates mat files which names are asdf, dfgh and assign...

## Import java package from Matlab deploytool to Android Studio App

java,android,image,matlab,jar
I managed to create a java package from a Matlab function (for image processing) using deploytool. I tested it in Eclipse and it runs perfectly. The problem is that I want to use this Matlab function for an Android Studio project and I can´t find any way to make it...

## Properly using button/checkbox callback

matlab,matlab-guide
I have some problems when it comes to defining a callback function and using handles. h1 = uicontrol('style','pushbutton','units','pixels',... 'position',[40,5,70,20],'string','test',... 'callback',@h1_call); I create a button with the code above and want to plot some information stored in the handles if I push on this button. function h1_call(handles) axes(handles.ax1) plot(handles.x,handles.y); sadly this...