Solved

frame of the matrix
Given the matrix M, return M without the external frame.

1 year ago

Solved

Replace Nonzero Numbers with 1
Given the matrix x, return the matrix y with non zero elements replaced with 1. Example: Input x = [ 1 2 0 0 0 ...

1 year ago

Solved

matrix zigzag
Unfold a 2-D matrix to a 1-D array in zig-zag order, e.g., for matrix [ 1 2 3 ; 4 5 6 ; 7 8 9 ] the resulting 1-...

1 year ago

Solved

Given a matrix, swap the 2nd & 3rd columns
If a = [1 2 3 4; 1 2 3 4; 1 2 3 4; 1 2 3 4]; then the result is ans = 1 3 2 4 1 3 2...

1 year ago

Solved

Operate on matrices of unequal, yet similar, size
You may want to add a vector to a matrix, implying that the vector is added to each column of the matrix. Or multiply a 3x4x5 ma...

1 year ago

Solved

Project Euler: Problem 1, Multiples of 3 and 5
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23...

1 year ago

Solved

Some Assembly Required
The input to this function is a matrix of real numbers. Your job is to assemble the rows of the matrix into one large row that ...

1 year ago

Solved

Removing rows from a matrix is easy - but what about inserting rows?
Assume A is a 5-by-5 matrix. A([2,4],:) = [] is a quick way to remove rows 2 and 4. Can you find a quick way to insert rows into...

1 year ago

Solved

Matrix with different incremental runs
Given a vector of positive integers a = [ 3 2 4 ]; create the matrix where the *i* th column contains the vector *1:a(i)...

1 year ago

Solved

Reverse the elements of an array
Reverse the order of elements in an array: eg: input X = [ 1 2 3 ; 4 5 6 ; 7 8 9 ] o...

1 year ago

Solved

Rotate input square matrix 90 degrees CCW without rot90
Rotate input matrix (which will be square) 90 degrees counter-clockwise without using rot90,flipud,fliplr, or flipdim (or eval)....

1 year ago

Solved

Make an awesome ramp for a tiny motorcycle stuntman
Okay, given a vector, say v=[1 3 6 9 11], turn it into a matrix 'ramp' like so: m=[1 3 6 9 11; 3 6 9 11 0; 6 9 ...

1 year ago

Solved

Set some matrix elements to zero
First get the maximum of each *row*, and afterwards set all the other elements to zero. For example, this matrix: 1 2 3 ...

1 year ago

Solved

Back to basics 23 - Triangular matrix
Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix, return a matrix with all elements above a...

1 year ago

Solved

Permute diagonal and antidiagonal
Permute diagonal and antidiagonal For example [1 2 3;4 5 6;7 8 9] -> [3 2 1;4 5 6;9 8 7] WITHOUT diag function (and variable n...

1 year ago

Solved

Flip the main diagonal of a matrix
Given a n x n matrix, M, flip its main diagonal. Example: >> M=magic(5); >> flipDiagonal(M) 9 24 1 ...

1 year ago

Solved

surrounded matrix
With a given matrix A (size m x n) create a matrix B (size m+2 x n+2) so that the matrix A is surrounded by ones: A = [1 2 ...

1 year ago

Solved

Project Euler: Problem 2, Sum of even Fibonacci
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 te...

1 year ago

Solved

Back to basics 21 - Matrix replicating
Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix, generate an output matrix that consists o...

1 year ago

Solved

N-Dimensional Array Slice
Given an N-dimensional array, _A_, an index, _I_, and a dimension, _d_, return the _I_ th elements of _A_ in the _d_ dimension. ...

1 year ago

Solved

Remove NaN ?
input -> matrix (n*m) with at least one element equal to NaN; output -> matrix(p*m), the same matrix where we deleted the enti...

1 year ago

Solved

Easy Sequences 102: One-line Code Challenge - Take While Function
takeWhile is another useful functional programming construct. The takewhile function is similar to the built-in function arrayfu...

1 year ago

Solved

Find similar sequences
Another problem inspired by a question on the <http://www.mathworks.com/matlabcentral/answers answers> forum. Given a matrix ...

1 year ago

Solved

Mersenne Primes vs. All Primes
A Mersenne prime (M) is a prime number of the form M = 2^p - 1, where p is another prime number. <https://www.mathworks.com/matl...

1 year ago

Solved

Largest Geometric Series
Extension of Ned Gulley's wonderful Problem 317. In a geometric series, ratio of adjacent elements is always a constant value. ...

1 year ago

Solved

geometric progression
I've modified my <http://uk.mathworks.com/matlabcentral/cody/problems/2800-arithmetic-progression previous program> so that it n...

1 year ago

Solved

arithmetic progression
I've written a program to generate the first few terms of <https://en.wikipedia.org/wiki/Arithmetic_progression arithmetic progr...

1 year ago

Solved

Generate Square Wave
Generate a square wave of desired length, number of complete cycles and duty cycle. Here, duty cycle is defined as the fraction ...

1 year ago

Solved

Sum of series VII
What is the sum of the following sequence: Σ(km^k)/(k+m)! for k=1...n for different n and m?

1 year ago

Solved

Sum of series VI
What is the sum of the following sequence: Σk⋅k! for k=1...n for different n?

1 year ago