Jos (10584)
Last seen: 14 days ago
1,527 total contributions since 2006I 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!"
Jos (10584)'s Badges
Your submissions were downloaded 250 or more times in a month
Awarded to Jos (10584) on 01 Nov 2019
Your submission is selected as "Pick of The Week"
Awarded to Jos (10584) on 09 Oct 2019
Publish your first comment or rating
Awarded to Jos (10584) on 09 Oct 2019
Your submissions received 25 five star ratings
Awarded to Jos (10584) on 09 Oct 2019
Publish your first submission
Awarded to Jos (10584) on 09 Oct 2019
Contribute at least one answer each month for 24 consecutive months
Awarded to Jos (10584) on 31 Jul 2019
Accept 5 answers given by other contributors
Awarded to Jos (10584) on 26 Jun 2018
Answer 1 question that was unanswered for more than 30 days
Awarded to Jos (10584) on 12 Feb 2018
100 of your answers have been accepted
Awarded to Jos (10584) on 20 Jul 2017
Provide your first answer ever to someone else's question
Awarded to Jos (10584) on 20 Jul 2017
15-year anniversary Scavenger Hunt finisher badge
Awarded to Jos (10584) on 09 Nov 2016
Be the first to solve a problem
Awarded to Jos (10584) on 03 Feb 2012
Solve a problem for the first time
Awarded to Jos (10584) on 03 Feb 2012
for loop taking too long to operate
Pre-allocation, and recoding using logical indexing and sum should speed things up popn1 = nan(300,1) ; % pre-allocation for i...
7 months ago | 1
| accepted
How to make columns the same size
A solution: A = [1 3 ; 2 4 ; 5 7] B = [10 11 12 ; 13 14 15] newB = repmat(mean(A,2), 1, size(B,2)) newB(1:size(B,1),:) = B
1 year ago | 0
| accepted
How can I search a cell array for all instances of a character and replace it with something else?
Something along these lines, perhaps? C = {1.1 pi '*' ; 3 '*' 2.2} tf = cellfun(@(x) isequal(x,'*'), C) idx = find(tf)
1 year ago | 0
If a number in a matrix is <9 add 5 to it
Use the same selection on the right hand side of the equal sign A(A<9) = A(A<9) + 5 I myself prefer to code it like this tf =...
1 year ago | 0
| accepted
How to set the diagonal of a cell array of matrices?
Well found, Mohammed! You should put as an answer here :-) Here is another method A = cell(4,4) % a cell array n = size(A,1)...
1 year ago | 0
| accepted
how to add a row and column to a matrix ?
One easy option is to do this for rows and columns separately A = [1 2 3 ; 4 5 6 ; 7 8 9] x = 3 ; % add a row/column of ones b...
1 year ago | 2
| accepted
How can I assign a variable to all the columns and all the rows of a matrix?
Are you looking for the function SIZE? data = rand(20,10) ; [numsubs, numtrials] = size(data)
1 year ago | 0
| accepted
Can this line in a code be written in a smarter way?
as others have mentioned before this makes ones head spin ... However, C(:,:,c)=(dC*C(:,:,c)+(dC*C(:,:,c)')'+C(:,:,c)*(-b)+C(:...
1 year ago | 0
Indexing sections of arrays
x = 101:110 n = 3 tf = mod(0:numel(x)-1, 2*n) < n a = zeros(size(x)) a(tf) = x(tf) index = find(tf)
1 year ago | 1
| accepted
combinations with 2 columns
Take a look at ALLCOMB on the File Exchange: https://uk.mathworks.com/matlabcentral/fileexchange/10064-allcomb-varargin X = [1...
1 year ago | 0
Combination of 4 Element
I make use of my function NCHOOSE, available here: https://www.mathworks.com/matlabcentral/fileexchange/20011-nchoose % bl is ...
1 year ago | 0
| accepted
How to find angle between two lines?
Use the dot product between the two vectors (v1 and v2) given by the four x,y pairs points. Given the formula: dot(v1,v2) = | ...
1 year ago | 0
The most efficient way to locate the first 1's in each row of a matrix
m = [0 1 1 1 ;1 0 1 0; 0 0 1 1 ; 0 0 0 1] % a simple solution [r, c] = find(m') ; clear v1 v1(r,1) = c % another solution ...
1 year ago | 0
Could anyone suggest me is there any way of choosing maximum and minimum values together
Here is a nice trick that also allows you to combine functions in a single call, which also can return the other outputs of thes...
1 year ago | 1
How to have a multiple choice questionnaire that will ask the next question depending on the answer?
Take a look at all the dialog functions in matlab like questdlg, listdlg etc. Start however drawing a graph of all the question...
1 year ago | 0
how to find nearest date corresponding value ?
Does this return what you want? R = AOD_440(closestIndex, [1 2]) % select first (date?) and second (values?) columns
1 year ago | 0
| accepted
Plotting an Archimedean Spiral
In the computation of x and y you wrongly multiply b with Th. You should multipy by Th / (2*pi): r = 12.5; %outer radius a =...
1 year ago | 0
| accepted
replace duplicate value by 0 in matrix or vector
% for small vectors: b = [1 2 1 3 2 1 4 2] b(sum(triu(b == b')) > 1) = 0
1 year ago | 1
concatenate arrays after performing addition
A little simpler than all those permutes and reshapes: A = [1 2 3 ; 4 5 6 ; 7 8 9] ; B = [2 3 4 5] ; C = repmat(A, numel(B), ...
1 year ago | 0
Alternation without for loop
% a sorting trick A = [1 2 3 4 5 6 7 8 9 10] B = [0.5 0.2 0.4 0.8 0.9] C = [A B] ; [~,ix] = sort([1:numel(A) 1:numel(B)]) C...
1 year ago | 0
Matching closest values to each other
For larger vectors, where BSXFUN will require a lot of memory, function NEARESTPOINT might be useful A = rand(1000000,1) ; B = ...
1 year ago | 1
| accepted
Sort Descend Scientific Notation Error
You misuse the sort command. Simply: sortedu = sort(u ,'descend') would do :-) Moreover, if you remove the semicolons, you ...
1 year ago | 0
making an array to simulate states of a paramagnet with values of -1,+1.
Create a random vector with two values and map those to -1 and 1. An easy solution (with n=10): x = 2 * randi([0 1], 1, 10) - 1...
1 year ago | 0
| accepted
for loop that changes specific letters to numbers
Another option: str = 'apple'; TF1 = any(lower(str) ~= 'aeiou'.')
1 year ago | 2
Finding Min Value in array with changing condition
tf = a == 1 % create a logical array temp = cost(tf) % logical indexing to retrieve certain values mincost = min(t...
1 year ago | 0
How to genetate random number under constraint
Brute force attempt: N = 20 ; xyRange = [100 1900] ; minimumDistance = 200 ; attempt_counter = 1 ; Distances = 0 ; while ...
1 year ago | 0
Add an element to a 3D array
To concatenate two arrays A and B in the third dimension, use cat cat(3, A, B) Note that all the other dimensions of A and B s...
1 year ago | 0
To concatenate rows in matrix within for loop based on if else statement
This code is weird. In each iteration of "index" you fill either a matrix temp or a matrix temp_noise with m rows of values. T...
1 year ago | 1
To generate matrix from an array
More general, using indexing: A = [1 22 3 44 55 666 7 888 9] n = 2 B = A(((1:numel(A)-n).' + (0:n)))
1 year ago | 0
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
Select web siteYou can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)