Answered
randomAffine3d is not properly random
EDITED: If you don't like what the default randomizer is doing, randomAffine3d() also let's you define your own, e.g., ori = [e...

1 year ago | 0

Answered
randomAffine3d is not properly random
If you want an isotropic distribution across the entire sphere, this should do it. ori = [eye(3);-eye(3)]; N=1000; o=cell(N...

1 year ago | 0

Answered
slow imwarp with large arrays
20k x 20k is an incredibly high resolution. Do you really need it, and if so, do you really need to use cubic interpolation, as ...

1 year ago | 0

Solved

Sum along each diagonal of a matrix
Write a routine that returns the sums along the diagonals of a given matrix, A, where the first diagonal is the bottom left corn...

1 year ago

Answered
Warning: Equation is badly conditioned. Remove repeated data points or try centering and scaling.
9th order polynomials do tend to be badly conditioned. Try using a lower order, or perhaps a spline model.

1 year ago | 0

Answered
help counting number of times a value occurs across matrix
values = [111, 112, 121, 122, 211, 212, 221, 222, 311, 312, 321, 322, 411, 412, 421, 422]; edges=[values,inf]; dp = [111 112...

1 year ago | 0

Problem

Sum along each diagonal of a matrix
Write a routine that returns the sums along the diagonals of a given matrix, A, where the first diagonal is the bottom left corn...

1 year ago | 1 | 22 solvers

Answered
Unable to achieve desired speed up using parfor
I find that all instances on B finish in about half the time as those on A. It baffles me... That is the expected result, assu...

1 year ago | 0

Solved

Sum All Positive Elements
Output a scalar that is equal to the sum of all positive elements in a given vector/matrix. For Example: The sum of all positi...

1 year ago

Solved

Build a block Toeplitz matrix
A symmetric block Toeplitz matrix has the form, where the are compatibly-sized matrices. Write a routi...

1 year ago

Answered
How to avoid unrecognized option names using optimget
Although I am using R2024a, that particular code still uses an older (2016-2019) version of lsqcurvefit. If so, problem solved....

1 year ago | 0

| accepted

Problem

Build a block Toeplitz matrix
A symmetric block Toeplitz matrix has the form, where the are compatibly-sized matrices. Write a routi...

1 year ago | 0 | 6 solvers

Answered
Finding the Center of Broken Vase Slices
You can use ellipticalFit() from this download, https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-tool...

1 year ago | 1

Problem

Condition number of Kronecker product
Given NxN matrix A and MxM matrix B, where M,N<=1000, write a routine to compute the condition number of kron(A,B).

1 year ago | 0 | 7 solvers

Solved

2x2 binning of a large sparse matrix
Consider the 20000 x 20000 sparse matrix, A=round(sprand(2e4,2e4,1/1e4*100)*1000); The task is to divide this matrix into 2x...

1 year ago

Solved

Convert a vector into numbers
Suppose a vector x = [ 1 2 4 7] is given. You have to convert this vector into string number y = '1247'. Examples x = [ 1...

1 year ago

Solved

Reverse within string
If input is a string 'yellow' the output should be 'leywol'. Locate the middle of the string and reverse the first (yel) and sec...

1 year ago

Solved

Minimum Distance Point to Segment
This Challenge is to determine the minimum distance from a 2-D line segment defined by two points to a point. The point is (p...

1 year ago

Solved

Property dispute!
Two neighbors have rectangular plots of land A and B. The surveyors give you the coordinates of each. If they overlap, there is ...

1 year ago

Solved

Project Euler: Problem 10, Sum of Primes
The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below the input, N. Thank you <http:/...

1 year ago

Solved

Extract diagonal of sparse quadratic form
Consider the matrix A and vector v given by, A=round(sprand(5e3,1e4,1/1e4*100)*100); v=randi(10,width(A),1); Write a rout...

1 year ago

Problem

Extract diagonal of sparse quadratic form
Consider the matrix A and vector v given by, A=round(sprand(5e3,1e4,1/1e4*100)*100); v=randi(10,width(A),1); Write a rout...

1 year ago | 1 | 5 solvers

Problem

2x2 binning of a large sparse matrix
Consider the 20000 x 20000 sparse matrix, A=round(sprand(2e4,2e4,1/1e4*100)*1000); The task is to divide this matrix into 2x...

1 year ago | 0 | 5 solvers

Solved

Do the line-segments intersect?
You are given two line segments. Do they cross? Consider one segment as (x1,y1) to (x2,y2), the other segment as (x3,y3) to (x4...

1 year ago

Solved

swap sign sum & multiply castles
It is an easy problem, if you know the answer. Given a square matrix of NxN ordinary numbers. Initially place N identical indi...

1 year ago

Solved

Flipping
Write code that can reverse the vector without using any sort of loop. Example Given the input vector A = [ 1 2 3 4 5...

1 year ago

Solved

Flip the diagonal values
Write a program that flip the elements of main diagonal , upper and lower diagonal values of a sqare matrix. For example if a ...

1 year ago

Solved

Flip the bit
Given an input character string (e.g. '1001'), return a character string with the bits flipped ('0110').

1 year ago

Solved

Flipping a Matrix
Flipping matrix up and down. If a central row is exists, leave it, and flip remaining rows. Example Mat = magic(3) ...

1 year ago

Solved

Swap two numbers
Example Input: a = 10 b = 20 Output a = 20 b = 10

1 year ago