Jan

Last seen: Today

12,696 total contributions since 2009

It is easier to solve a problem than to guess, what the problem is.

Questions about FileExchange submissions are welcome - get my address from the code. I do not answer mails concerning questions in the forum.

Jan's Badges

View details...

Answered
Min and max value of many results
Use a vectorized method to obtain the results as a vector, not as a bunch of single variables: w = 0:0.001:1.393; k = 2; ...

2 days ago | 2

Answered
Unrolling a 20x20 grid of pixels into a 400 dimensional vector.
If the data are a collection of 500 matrices of the size 20x20: data = rand(5000, 20, 20) You can create the 2D matrix by: da...

3 days ago | 0

Answered
what is the probleme exactly u must be of size[3,20] but i find it [3,1]
Let me guess boldly: You want: A = [5/8, -1/4, 1/8; 1/4, 0, 1/4; 1/8, -1/4, 5/8]; b = [1;-1;1]; u = [5; 2; -4]; m = 20; u =...

3 days ago | 0

Answered
Vector ODE using forward Euler method
You have replaced the "x" of the formula by "y(1)", the "y" by "y(2)". Now you have to replace "u" by "y(3)" also and "v" by "y(...

5 days ago | 1

Answered
how to convert grey image to RGB
Your Pi is a [130 x 130 x 60] matrix, but your function gray2rgb() expects a 2D matrix as input. It is not clear how you want to...

6 days ago | 0

Answered
imread reads PNG files as empty arrays
When I run your code in Matlab 2018b I get a different result: img = imread('18_1b.png'); size(img) % 500 x 500 x 3, not...

6 days ago | 0

Answered
Increment components of vector till a desired limit
You know in advance how many iterations are needed: The smallest element must be increased until it is 100. A = [1 2 3 4 5...

7 days ago | 1

| accepted

Answered
Making sure the maximum calculated value in my function is represented in ode15s output.
ODE15S is designed to integrate smooth functions, as the other ODE integrators of MATLAB are. Running it with this not different...

7 days ago | 1

| accepted

Answered
Derivative without diff function
"Not enough input arguments. Error in @(x,t)x/t" You have defined fun to use 2 input arguments: fun = @(y,t) y/t; But in fun...

7 days ago | 0

Answered
Get all unique combinations from cell array for use as functional arguments
This can be achieved by 2 loops using linear indexing: for i1 = 1:numel(data) for i2 = 1:numel(data) immse(data{i...

7 days ago | 0

Answered
Combining cell arrays with empty doubles
Or simpler: a = {1, []}; b = {[], 2}; c = cat(2, a, b); c = c(~cellfun('isempty', c)); % Or: fullCell = @(x) x(~cellfu...

7 days ago | 0

Answered
Why I get this message?
Use the debugger to check the sizes of the arrays: dbstop if error Type this in the command line and run the code again. When ...

7 days ago | 0

Answered
Appending to a very large file
This line increases the problem: signal_mat = vertcat(signal_mat,temp_2); In e.g. the last step, you concatenate a 63 GB array...

8 days ago | 0

Answered
How would I convert a script to a function?
All you have to do to convert it to a function, is to add a head line: function array = randArrGen Maybe you want to define n ...

8 days ago | 0

Answered
check for keyboard press while using another application (such as Chrome)
The key should be caught, while the browser is the active window? This is a keyboard sniffer and running it might be conflict wi...

8 days ago | 0

Answered
Keeping the debugger out of the bowels of the machine...dbstop error question
This can be avoided by an exhaustive error checking, which catchs all not matching inputs as early as possible. Massive TRY-CATC...

8 days ago | 0

| accepted

Answered
How to return values of differential, not the function, from odefun, ode45?
You want the values of dy2dt? But you do have the equation for it already: dy2dt = (param.m2*y4^2*y1-param.k*y1+param.k*param.l...

8 days ago | 0

Answered
Append rows at the end of matrix for loop
A = rand(5, 2); B = rand(3, 2); Result = cell(1, 3); for k = 1:3 Result{k} = [A; B(k, :)]; end

8 days ago | 0

Answered
C++ Blur function to MATLAB code
You have redefined the function name "sum" as name of a variable. After sum=sum(A(:)) the symbol "sum" is a variable. The next t...

9 days ago | 0

| accepted

Answered
Two files with equal contents but with different SHA256 digest
The TIF files do not even have the same file sizes. How could you expect, that they are bit-wise identical then, which is requir...

12 days ago | 0

| accepted

Answered
Find maximum array values avoiding mat2cell.
For the expanded question in the comment to Bruno's solution you ask for the n largest elements: A = [NaN, NaN, NaN, NaN, 1, 6,...

16 days ago | 2

Answered
Creating dynamic variables using loops | Automatic Variables using loops
[EDITED]: The direction for shiftig needs a minus sign and is applied along dimension 1: Ha = [1 2 4 8 16; ... ...

16 days ago | 1

| accepted

Answered
Cell array construction operator
Did you pre-allocate the cells before the loop? n = length(ARRAY); find_fcn1 = cell(n, 1); find_fcn2 = cell(n, 1); find_fcn3...

17 days ago | 0

Answered
How to save in a drag and drop
There are some problems with the movement: The object does not move exactly as the mouse. But you are asking for saving the pos...

17 days ago | 0

Answered
Get all graphs from ODE23
Vectorize the function to be integrated: Then it accepts a matrix with different X values also: tspan = 0:0.025:2.5; x0 =...

17 days ago | 1

Answered
Terminating function call with CTRL-C but keep the main function working
What about starting another Matlab instance? Then you can kill it by taskkill of the operating system (assuming you are running ...

17 days ago | 0

Answered
How to capture the increasing values patch(sub-vector) in matlab scripting ?
A = [1 1 1 0 -1 2 3 6 7 0 0 1 2 3]; D = [false, diff(A) > 0, false]; starting = strfind(D, [false, true]) ending = strfind(...

17 days ago | 0

Answered
How to change the language of MATLAB online?
Most likely by pressing this button on the left bottom:

17 days ago | 0

Answered
checking if a nested field exists
In your code: isfield(['A.' D.E.F{i}],'C') what is D.E.F{i}? A concatenation with 'A.' will create a char vector. Char vectors...

17 days ago | 1

Answered
In matlab R2015a in windows 10 mex -setup is not able find compiler, i had install sdk7.1. Sir plz help me to solve this problem. Thank you in advance!
Did you select the 64 bit compiler during the setup?

17 days ago | 0