Community Profile # Simon Chan

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Active since 2021

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Try using function cart2pol, following is an example clear; clc; Ny = 1000; Nx = 1000; Nz = 30; ...

18 days ago | 0

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What's the problem here?
function im2gray does not accept the jpg image, it accepts the image in pixel values Try the following: pic = imread('good_day...

20 days ago | 0

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Figure with 17x17 subplot
Another option is use function tiledlayout tiledlayout(17,17,'TileSpacing','none','Padding','none'); nexttile

20 days ago | 0

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Try the following for an excel file name 'demo.xlsx', and sheet name 'Signals'. It is the same for readtable or readmatrix. re...

22 days ago | 1

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My frequency plot isn't showing anything
The idexing for frequency and residual torque, variable w and S starts from 1 to 1000 and from 2 to 11 resepctively. So I think...

22 days ago | 0

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Add '_max' to odd variable names and '_min' to even ones.
Suppose the table is called T, then try the following: T.Properties.VariableNames(1:4) = {'t_max','t_min','ang_azi_max','ang_az...

28 days ago | 0

How do a cell2mat conversion for a non-uniform cell to a matrix
Do it in several steps as follows: idx.size = cellfun(@length,DD); idx.padded = max(idx.size)-idx.size; DDpadded = cellfun(@(...

28 days ago | 1

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Differentiate between oval and circle shaped images using MATLAB
You may try function bwconvhull by adding the following 2 lines. However, I am not sure how robust it is for other pictures. B...

30 days ago | 0

how to join the values of different cells in different columns in one cell ?
Suppose you read the file using function readtable and the name of the table is T, then variable C in the following will give yo...

30 days ago | 0

How to change the color of my plots
Just put the color code for the markers. May try the following: for n=.3*N:N x=(1-d).*x.*exp(a.*(1-x).*((x/0.2)-1))+d.*y.*...

30 days ago | 0

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Fix "index exceeds number of array elements"
j is going to be the index and hence theta_x should not be use Try the following: for j=1:length(theta_x) s(j)=L1(j)^2+L2...

1 month ago | 0

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How to use writematrix to create a single xlsx file with multiple sheets with name of the analysis file?
Use function <https://www.mathworks.com/help/matlab/ref/fileparts.html fileparts> to extract the name instead of the entire file...

1 month ago | 1

find ID's of repeated values in array
You may use a for loop as follows: idx = zeros(1,length(t1)); for k = 1:length(t1) idx(k) = find(ismember(t2,t1(k))); en...

1 month ago | 0

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cration of contents inside the cell array of uniform size
May try the following to add NaN to the new rows load('data.mat'); addrow = cellfun(@(x) 8-size(x,1),Data,'uni',0); result = ...

1 month ago | 0

Why is it not working?
Index jj is not defined inside the for-loop, i guess the code should be modified as the following for ii=1:26 for jj = 1:2...

1 month ago | 0

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Index in position 2 exceeds array bounds (must not exceed 1) ?
One of the input argument is variable 'c' and you use the same name again for the size of variable 'a' and hence gives you an er...

1 month ago | 1

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Area fill under a curve
Check the MATLAB documentation about area. w is a function handle and it is not supported. Try the following: x=linspace(0,2*...

1 month ago | 0

Separate 24 digits single array of data loaded from file into 6 different arrays
Try the following by converting the text using function num2cell. clear; clc; fid = fopen('data.txt'); d = textscan(fid,'%s')...

2 months ago | 0

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Try Otsu's method rawdata=imread('capture 1.png'); I = rgb2gray(rawdata); level = graythresh(I); BW = imbinarize(I,level); ...

2 months ago | 1

what happened to my install ?how to solve this proplem?
If your installation runs on WIndows, please check whether you have adminstrator right or not. On the other hand, you may refer...

2 months ago | 0

Plot 3D surface from Excel .csv File
You may extract the data using function readmatrix. clear; clc; rawdata = readmatrix('data.csv'); x = reshape(rawdata(:,1),[]...

2 months ago | 1

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How to write new data to the existing excel file?
You may replace the entire loop by using 'Append' as follows: writetable(T,'Results.xlsx','UseExcel', true, 'WriteMode','Append...

2 months ago | 0

Plots with different colors
Put the index and hold on inside the loop figure(1) for i=1:length(Re) if Re(i) < 2*10^3 loglog(Re(i),f(i),'xb','Lin...

2 months ago | 0

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How can I set the colorbar for a specific series of value ?
Adjust the Limits and Ticks as follows: cb = colorbar cb.Limits = [300 2100]; cb.Ticks=300:300:2100;

2 months ago | 0

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Best fit line in log-log scale
Like this? p=polyfit(log(X),log(Y),1); y=polyval(p,log(X)); figure(1) loglog(Re,f,'x','LineWidth',1) hold on loglog(X,exp(...

2 months ago | 0

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How to sort a 3D matrix according to the value of each element?
If I understand correctly, you would like the larger value(s) in the last rows and the largest one on the bottom right hand cor...

2 months ago | 0

using matlab fileread function for some portion of text data
Use function textscan to read the first 50 lines and the header will be stored on a cell array. fid = fopen(fullfile(filepath,f...

2 months ago | 1

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Subplot arrangement: 6 by 2 plot
Try this: figure(1) subplot(6,2,1) plot(1:10,randi(10,1,10)) hold on subplot(6,2,3) plot(1:10,randi(10,1,10)) subplot(6,2...

2 months ago | 0

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How to label the centers of circles according to their position on axes?
Try this and still using function text: clear; clc; I = ones(400,600); sorted_centers_x = repmat(50:100:550,1,4); sorted_cen...

2 months ago | 1

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