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Matrix does not want to multiply and gives an error when I multiply a 3x3 matrix with a 3x1 matrix
Read the INV documentation! And then use the recommended function MLDIVIDE: A = [9, 29.3, 140.99; 29.3, 140.99,827.693; 140.99,...

1 year ago | 0

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alternative of inline function
If you want a derivative, why are you using a function handle? Using symbolic toolbox would be simpler: syms x f = x^2-2*x g ...

1 year ago | 1

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Answered
Find minimum values based on unique number
P = load('matlab.mat').Prof_temp S = groupsummary(P,"Profile_num","min","Temp") plot(S.Profile_num,S.min_Temp)

1 year ago | 0

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Spli cell array directly at the function output
If you can modify the function to return another output argument the size of the returned cell arrays is only known when they ...

1 year ago | 0

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How to fix loop which over the determined index ?
"Hi guys, im trying to do looping ii 1:900 but why when u run it, it was never-ending loop." I already told you the reason why,...

1 year ago | 0

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Duration type doesn't preserve seconds accuracy
"Duration type doesn't preserve seconds accuracy" That is exactly what CALENDARDURATION objects are for: format longg dt1 = d...

1 year ago | 0

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Find min and max in groups
A = [12, 11, 12, 5, 3, 10, 5]; B = [0.1, 0.1, 0.1, 0.7, 0.4, 0.3, 0.2]; X = 1:numel(A); Fmax = @(x){x(max(B(x))==B(x))}; Fmi...

1 year ago | 0

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Answered
Use save function with '-fromstruct' option to save a cell array
As the error message states, the structure must be scalar: test_file = 'test.mat'; files = {'test1.m', 'test2.m'}; T = ones(1...

1 year ago | 2

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Answered
How to write to csv file in shortG format?
Here is one approach that gives exactly the shortG format in your CSV file: format long G M = rand(3,5); M(1) = -6.0247123456...

2 years ago | 1

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Answered
I need help with an error I get
Perhaps the input argument should be F (not f): function [posicao, velocidade, aceleracao] = atleta(t, F, M)

2 years ago | 1

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Answered
When multiplying or dividing a vector by a scaler, when do you need a period before the operator?
"When multiplying or dividing a vector by a scaler, when do you need a period before the operator?" Lets consider multiplying. ...

2 years ago | 0

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Observations being read as number of columns instead of rows
Perhaps because the data are (complex conjugate) transposed here: 'ValidationData', {stan_x_val', stan_y_val'}, Note that yo...

2 years ago | 1

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Answered
Need help figuring out why this nested function is not working
"File not found" You are not providing FOPEN and READMATRIX with the filepath, so they cannot find the file on your computer. P...

2 years ago | 0

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Answered
Can't seem to replace values in matrix meeting criteria, although the correct row,col coordinates are found
Use SUB2IND: idx = sub2ind(size(img),row,col); img(idx) = 1; The section "Indexing Matrices with Two Subscripts" here: https...

2 years ago | 0

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Answered
Compare two files and remove any lines in the second file when they match values found in the first file
lines1 = [1,2,3,4;2,4,6,7;2,5,7,8;6,7,4,6] lines2 = [2,4,6,7;2,5,7,8] out = setdiff(lines1,lines2,'rows')

2 years ago | 0

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Answered
A more efficient or compact way to sort strings that contain dates
a = [... '123_abc_01_202403020000_202403022359.txt'; '123_abc_01_202403040000_202403042359.txt'; '123_abc_01_2024...

2 years ago | 1

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Answered
Portion of code containing my custom functions is hidden and I cant access it.
The feature is called code folding: https://www.mathworks.com/help/matlab/matlab_prog/edit-and-format-code.html#brazeg3-1 http...

2 years ago | 1

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How can I access the value of a string variable? I need to construct a file path from a string variable, but keep getting the variable name and not the string.
It works perfectly, exactly as you showed in your question: directory_name = "directory1"; f = fullfile('/Users/me/ch4', direc...

2 years ago | 1

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Appending data when extracting nested fields as individual variables
The simple and efficient MATLAB approach using two comma-separated lists (no loops are required!): first100 = load('frames.mat'...

2 years ago | 0

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Answered
char array to numeric array
"I was wondering if there was a better way of doing this?" Of course, use READTABLE (or READMATRIX): unzip tab_file_table.zip ...

2 years ago | 0

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Answered
I'm trying to convert the text into binary and then i want to make the 4 bits chunks.
message = 'Hello world'; A = dec2bin(message, 8) B = reshape(A.',1,[])

2 years ago | 0

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How to stop double printing text using sprintf ?
Problems: 1- This is the relevant code: VariantModel = compose('%d', 1:height(VariantIDPassed)); .. writefile(VariantModel{i...

2 years ago | 0

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Answered
How do I fix my Nan issue within a recursive function?
Replace this (which returns logical indices): FirstID = M==-1; with this (which returns the linear index): FirstID = find(M==...

2 years ago | 0

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How to import multiple .mat files to workspace?
The basic problem is that you are not supplying the filepath to LOAD. You can improve your code as well. I am guessing that you...

2 years ago | 0

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Answered
Error in code, parenthesis perceiving as comment for some reason
Explanation: for some reason you seem to be running this literal code: Q_est = updateQ(...) instead of calling UPDATEQ etc. wi...

2 years ago | 1

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smart function to switch functions
You could use STR2FUNC: str = 'ode23'; odesolver = str2func(str); odesolver(@fun,..) or simply use FEVAL: feval(str,@fun,.....

2 years ago | 0

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Answered
Reshaping a matrix based on the first row
A = [270,270,270,271,272,272,273,273,273]; B = [ 12, 2, 3, 14, 5, 2, 6, 8, 11]; X = ~isnan(A); C = findgroups(A(X)); R...

2 years ago | 0

Answered
sorting non-exact x/y data into rows and columns, typewriter style
x = [1.01,2.01,1.02,2.02]; y = [1.01,1.02,2.01,2.02]; m = [x(:),y(:)]; % simpler [~,id] = sortrows(round(m),[-2,+1])

2 years ago | 0

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Answered
How can I extract an array of numbers from a text-formatted cell array of strings.
C = {'20s';'15m';'';'24s';'';'44s';'3h';'40m';'20s';'';'14s'} F = @(t)prod(sscanf(t,'%f')); V = cellfun(F,regexprep(C,{'h$','m...

2 years ago | 1

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Answered
Update an Excel file after each Matlab calculation
You can use a COM server to trigger Excel to recalculate the worksheets: https://www.mathworks.com/matlabcentral/answers/100938...

2 years ago | 0