Community Profile

# Jos (10584)

1,495 total contributions since 2006

I have been using Matlab since version 4 (1999 or so) and still prefer it over all other software tools available for data manipulation :-)

My professional interests: neuroscience (motor control & eye movements), cognitive psychology physics, mathematics, teaching

"The most important part of programming is writing the comments!"

View details...

Contributions in
View by

Could anyone help me to solve the issue.
ix = find(abs(diff(A)) < YourThreshold, 1, 'first') % maybe you want to add + 1 B(ix:end) = B(ix)

2 days ago | 0

How can I keep the highest N% values of a data set?
Use MAXK: Y = maxk(X, ceil(N * numel(X) / 100))

3 days ago | 1

Function calculating distance between pixels in 1x1x3 arrays
The function you found is rather badly coded ... Another expression for "calculating a distance" is "taking the norm". Matlab h...

8 days ago | 1

| accepted

how to extend the writing of the comments ?
You can set this in the preferences for the editor/debugger. Look for the Right-hand text limit.

9 days ago | 1

Best way to calculate the determinants of a series of matrices?
Elaborating on the answers using arrayfun, you can avoid the multiple squeeze operations by permuting the dimension order first:...

10 days ago | 0

Fill an array with different size vectors
A=[1,2,3,4]; B=[5,6]; C=[7,8,9]; [ARRAY, tf] = padcat(A,B,C) % pad with NaNs ARRAY(~tf) = 0 % replace those NaNs with zeros ...

10 days ago | 0

add new rows to a Matrix
Despite its simple appearance, this is not a trivial task, for which I created my insertrows function A = randperm(10).' B = i...

16 days ago | 0

reduce rows of a due to b
You can simply use setdiff with the rows option ... c = setdiff(a,b,'rows')

16 days ago | 0

exclude values of a matrix inside a for loop
you can replace the outliers by NaN before the loop and then use nanmax and nansum in your calculations

17 days ago | 0

| accepted

Find unique or duplicate cells in cell array of chars
A = {{'A', 'B', 'C'}, {'C', 'D', 'E'}, {'A', 'B', 'C'}, {'C', 'B', 'A'}} N = arrayfun(@(k) sum(arrayfun(@(j) isequal(A{k}, A{j}...

17 days ago | 1

| accepted

How to compare two vector with different dimension
I assume the elements of x and y are linked? Why is the first element of (x2,y2) than not in the list of coordinaties (x1,y1)? I...

17 days ago | 0

Solved

Back to Basics - Find no. of elements in a matrix?
Let A be a m*n matrix. Find the total no. of elements in A ? (Hint - formula based) A = [1 2 3;4 5 6]; output = 6

19 days ago

Submitted

uniqueperms
unique permutations of a set with repetitions

To generate alternate 0's and 1's
bitget(repelem(0:numel(A)-1, A), 1) [update] I modified my original but erroneous answer bitget(repelem(1:numel(A), A), 2). In ...

30 days ago | 1

Combine three matrices (every other column)
Or, as a one-liner, using left-hand indexing: % some test data A = cumsum(ones(5,4),2), B = 10 * A, C = 10 * B % left-hand in...

1 month ago | 0

| accepted

Combine three matrices (every other column)
Assuming matrices A, B and C all have the same N-by-M size: % some test data A = cumsum(ones(5,4),2) ; B = 10 * A ; C = 10 * B...

1 month ago | 0

Calculate statistical parameters from certain rows of a matrix
help grpstats help accumarray

1 month ago | 0

How to convert a structure array into vector
Why on earth store scalar values like that? Why not have a simple, highly efficient M-by-N matrix, rather than a cumbersome M-by...

1 month ago | 0

For loop within for loop
In recent ML versions there is no need for meshgrid or so. The plus syntax will expand the vectors :-) % a smaller example n =...

1 month ago | 1

Average of matrix element
One easy option A = [10 20 30 40] B = cumsum(A) ./ (1:numel(A))

1 month ago | 0

Extracting and sorting data in a column
This works for both an even or an odd number of elements: N = 11 ; % odd Mx = randi(10, N, 1) M2 = accumarray(ceil((1:numel(M...

1 month ago | 0

inefficient loop to vertically concatenate tables
You can apply comma-separated list expansion to tables too, so this one-liner should work. tableBig = cat(1, output{:,2})

1 month ago | 1

| accepted

Why is the mean of value of gaussian white noise not zero?
The numbers are randomly drawn from a normal distribution. Although this underlyin distribution has a mean of 0 and a standard d...

1 month ago | 0

| accepted

How to segment an array to different parts?
First of all, do not create separate variabeles for things that are related. A solution using cell arrays (like Kalyan does in h...

1 month ago | 0

convert an array into its counting sequence..
This is called run-length encoding, for which there are very efficient functions available on the File Exchange. https://uk.mat...

1 month ago | 0

How can I store a matrix of varying size in each iteration of a for loop?
Since T and Y are related for a specific value of rho, a struct array is useful here. rho_range = 500:100:1000 ; for k = 1:num...

1 month ago | 0

| accepted

Calculate mean values of specific (but dynamic) intervals
% interval and value are the relevant columns of your data matrix interval = data(:,3) value = data(:,2) % find the sections ...

1 month ago | 0

| accepted