Community Profile

photo

Jos (10584)


Last seen: 11개월 전 2006년부터 활동

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!"

통계

All
  • Scavenger Finisher
  • 24 Month Streak
  • Thankful Level 3
  • Speed Demon
  • Solver
  • Personal Best Downloads Level 4
  • Editor's Pick
  • First Review
  • 5-Star Galaxy Level 5
  • First Submission
  • Revival Level 1
  • Guiding Light

배지 보기

Content Feed

보기 기준

답변 있음
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...

3년 초과 전 | 1

| 수락됨

답변 있음
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

대략 4년 전 | 0

| 수락됨

제출됨


COLSHIFT
Circularly shift each column of a matrix

4년 초과 전 | 다운로드 수: 1 |

Thumbnail

답변 있음
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)

4년 초과 전 | 0

답변 있음
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 =...

4년 초과 전 | 0

| 수락됨

답변 있음
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)...

4년 초과 전 | 0

| 수락됨

답변 있음
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...

4년 초과 전 | 5

| 수락됨

답변 있음
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)

4년 초과 전 | 0

| 수락됨

답변 있음
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(:...

4년 초과 전 | 0

답변 있음
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)

4년 초과 전 | 1

| 수락됨

답변 있음
combinations with 2 columns
Take a look at ALLCOMB on the File Exchange: https://uk.mathworks.com/matlabcentral/fileexchange/10064-allcomb-varargin X = [1...

4년 초과 전 | 0

답변 있음
Combination of 4 Element
I make use of my function NCHOOSE, available here: https://www.mathworks.com/matlabcentral/fileexchange/20011-nchoose % bl is ...

4년 초과 전 | 0

| 수락됨

답변 있음
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) = | ...

4년 초과 전 | 0

답변 있음
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 ...

4년 초과 전 | 0

답변 있음
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...

4년 초과 전 | 1

답변 있음
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...

4년 초과 전 | 0

답변 있음
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

4년 초과 전 | 0

| 수락됨

답변 있음
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 =...

4년 초과 전 | 1

| 수락됨

답변 있음
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

4년 초과 전 | 1

답변 있음
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), ...

4년 초과 전 | 0

답변 있음
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...

4년 초과 전 | 0

답변 있음
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 = ...

4년 초과 전 | 1

| 수락됨

답변 있음
Sort Descend Scientific Notation Error
You misuse the sort command. Simply: sortedu = sort(u ,'descend') would do :-) Moreover, if you remove the semicolons, you ...

4년 초과 전 | 0

답변 있음
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...

4년 초과 전 | 0

| 수락됨

답변 있음
for loop that changes specific letters to numbers
Another option: str = 'apple'; TF1 = any(lower(str) ~= 'aeiou'.')

4년 초과 전 | 2

답변 있음
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...

4년 초과 전 | 0

답변 있음
How to genetate random number under constraint
Brute force attempt: N = 20 ; xyRange = [100 1900] ; minimumDistance = 200 ; attempt_counter = 1 ; Distances = 0 ; while ...

4년 초과 전 | 0

답변 있음
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...

4년 초과 전 | 1

답변 있음
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...

4년 초과 전 | 1

답변 있음
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)))

4년 초과 전 | 0

더 보기