Rik

Last seen: Today

2,488 total contributions since 2017

E-mails with feedback/questions about FEX submissions are welcomed. In general I will post e-mails about Answers on the related page, unless there is good cause not to do so.

Contact

Rik's Badges

View all

Solved

~~~~~~~ WAVE ~~~~~~~~~
|The WAVE generator| Once upon a time there was a river. 'Sum' was passing by the river. He saw the water of the river that w...

10 hours ago

Solved

Remove the air bubbles
Given a matrix a, return a matrix b in which all the zeros have "bubbled" to the top. That is, any zeros in a given column shoul...

10 hours ago

Solved

Draw 'E'
Draw a x-by-x matrix 'E' using 1 and 0. (x is odd and bigger than 4) Example: x=5 ans= [1 1 1 1 1 1 0 0 0 0 ...

10 hours ago

Solved

Piecewise linear interpolation
Given an Mx2 vector and a row of M-1 integers, output a two column vector that linearly interpolates Y times between each succes...

10 hours ago

Solved

We love vectorized solutions. Problem 1 : remove the row average.
Given a 2-d matrix, remove the row average from each row. Your solution MUST be vectorized. The solution will be tested for ac...

11 hours ago

Solved

intersection of matrices
Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identi...

11 hours ago

Solved

Generate N equally spaced intervals between -L and L
Given N and L, return a list of numbers (in ascending order) that divides the interval [-L L] into N equal-length segments. F...

11 hours ago

Solved

Create logical matrix with a specific row and column sums
Given two numbers *|n|* and *|s|*, build an |n-by-n| logical matrix (of only zeros and ones), such that both the row sums and th...

11 hours ago

Answered
How to sum different cells of cell array
Something like this should work: data={[1,2,3;4,5,6],[3,24,35;46,58,69]; [10,2,3;24,85,6],[11,22,33;54,15,16]}; data=perm...

16 hours ago | 0

Answered
How to plot vectors with different lenght
You need to make sure your data matches up. You can either remove the x-values you don't have a y for, or add NaN values for tho...

16 hours ago | 0

Answered
How to create a string that depends on user input variables?
You can create this text with sprintf and some minor tweaks: str=sprintf('p(%d)*x^%d +', [1:d;(d-1):-1:0]); str=strrep(str...

3 days ago | 0

Answered
Adding numbers in a row vector
You can do it with a for loop, but you should use cumsum instead.

3 days ago | 0

| accepted

Answered
I keep getting the error "Dimension argument must be a positive integer scalar within indexing range"
The trapz function does not allow an anonymous function as second input. You will need to calculate the y values. f= @(x) 2...

3 days ago | 0

| accepted

Answered
I want to make a series using max & mins of this Integral and show that the series converges and has the limit pi/2.
Your code already is making a series. You could add the envelope, but the only thing you're missing in my opinion is adding the ...

5 days ago | 0

| accepted

Solved

Return a list sorted by number of consecutive occurrences
Inspired by Problem 38 by Cody Team. Given a vector x, return a vector y of the values in x sorted by the number of CONSECUTIVE...

6 days ago

Solved

Replicate elements in vectors
Replicate each element of a row vector (with NaN) a constant number of times. Examples n=2, A=[1 2 3] -> [1 1 2 2 3 3] ...

6 days ago

Solved

Get the elements of diagonal and antidiagonal for any m-by-n matrix
In the problem <http://www.mathworks.com/matlabcentral/cody/problems/858-permute-diagonal-and-antidiagonal Problem 858. Permute ...

6 days ago

Solved

Getting the indices from a matrice
Getting the indices from a matrice. Inspired by Problem 645. Getting the indices from a vector by the great Doug Hull. Given a...

6 days ago

Solved

Set the array elements whose value is 13 to 0
Input A either an array or a vector (which can be empty) Output B will be the same size as A . All elements of A equal to 13...

6 days ago

Solved

Construct an index vector from two input vectors in vectorized fashion
Create an index vector defined by two input vectors, one defining the beginnings of one or more index ranges, and the other defi...

6 days ago

Answered
create a new 4D Array from 2 others
I think I understand what you mean. The code below will overwrite all values that are not NaN for a given depth, which is equiva...

6 days ago | 0

| accepted

Answered
Generating a random number from array based on requirements
A=[1,2,3,4]; p=[10 20 30 40]; c=cumsum(p); isAllowed=[3,4]; while true [~,r]=histc(rand(1,1),[0 c/c(end)]); if ism...

7 days ago | 0

Answered
Graph window is blank
As most of the operation you perform don't work for most shapes of input data, I'm assuming you're calling this code with scalar...

7 days ago | 0

Answered
How to write this for loop as a while
Every for-loop can be re-written to a while-loop. y = 0; k = 1; while k<=999 y = y + k*k; k = k + 4; end

7 days ago | 1

Answered
Modifying odd/even numbers of a column vector
If you have trouble with Matlab basics you may consider doing the Onramp tutorial (which is provided for free by Mathworks). x ...

7 days ago | 0

| accepted

Answered
Multi Dimension Matrix Elements multiplication
Not completely without loops, but this should be fast enough. You should also be aware that loops can sometimes be the fastest w...

7 days ago | 0

Answered
How to run function between each row
pairs=nchoosek(1:size(data,1),2); for n=1:size(pairs,1) row_a=data(pairs(n,1),:); row_b=data(pairs(n,2),:); %cal...

7 days ago | 0

Answered
Single line plot with fixed axis
Every axes object has an XScale property you can set to 'log' to get the desired plot. You can use the normal plotting tools (e....

7 days ago | 1

| accepted

Answered
How to click points in a figure to generate a function/set of data?
I would suggest getpts, although there is an alternative that gives visual feedback: ginput.

7 days ago | 0

Answered
how to generate 10^6 random binary values consisting only -1 and 1?
doc randi

8 days ago | 0