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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 ...

13 years ago

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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...

13 years ago

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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...

13 years ago

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DNA N-Gram Distribution
Given a string s and a number n, find the most frequently occurring n-gram in the string, where the n-grams can begin at any poi...

13 years ago

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The Goldbach Conjecture, Part 2
The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

13 years ago

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First N Perfect Squares
*Description* Return the first N perfect squares *Example* input = 4; output = [ 1 4 9 16 ];

13 years ago

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Remove DC
Input x is the sampled signal vector, may have both AC and DC components. Output y should not contain any DC component. Examp...

13 years ago

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Counting Sequence
Given a vector x, find the "counting sequence" y. A counting sequence is formed by "counting" the entries in a given sequence...

13 years ago

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Reverse Run-Length Encoder
Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

13 years ago

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Prime factor digits
Consider the following number system. Calculate the prime factorization for each number n, then represent the prime factors in a...

13 years ago

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Tic Tac Toe FTW
Given a tic tac toe board: * 1 represents X * 0 represents empty. * -1 represents O It is X's move. If there is an imme...

13 years ago

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Find the two most distant points
Given a collection of points, return the indices of the rows that contain the two points most distant from one another. The inpu...

13 years ago

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Connect Four Win Checker
<http://en.wikipedia.org/wiki/Connect_Four Connect Four> is a game where you try to get four pieces in a row. For this problem, ...

13 years ago

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Eliminate unnecessary polygon vertices
Suppose you have an n-point polygon represented as an n-by-2 matrix of polygon vertices, P. Assume that the polygon is closed; t...

13 years ago

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Return the Nth Output from an Input Command
*Description* Given _F_, a cell array whose first element is a function handle and subsequent elements are arguments, return ...

13 years ago

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Remove the two elements next to NaN value
The aim is to *remove the two elements next to NaN values* inside a vector. For example: x = [6 10 5 8 9 NaN 23 9 7 3 21 ...

13 years ago

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capable husband?
* The prospective husband must pass a background check, * and *functions* faithfully, as suggested by <http://www.mathworks.com...

13 years ago

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Column norms of a matrix
Given a matrix M, return a vector y such that for each k y(k)=norm(M(:,k)) (y(k) is the Euclidean norm of the k-th col...

13 years ago

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Matrix with different incremental runs
Given a vector of positive integers a (>=0); How does one create the matrix where the ith column contains the vector 1:a(i) poss...

13 years ago

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Find Rotated Substring
Given a string s1, find if a rotated version of s1 is present in a second string s2. For example, rotated version of some str...

13 years ago

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Back to basics 24 - Symbolic variables
Covering some basic topics I haven't seen elsewhere on Cody. Given a string algebraic expression, return the symbolic variabl...

13 years ago

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Convert a numerical matrix into a cell array of strings
Given a numerical matrix, output a *cell array of string*. For example: if input = 1:3 output is {'1','2','3'} whic...

13 years ago

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Function composition
Write a function that accepts two function handles f and g and returns the composition h. That is, h = (f o g)(x) = f(g(x)) ...

13 years ago

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Sort numbers by outside digits
Sort the array so that they are sorted as if their value was a 5 digit number made from the first three and last two digits of t...

13 years ago

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Find indices of multiple minima in a vector
I have a vector, say: x= [ 1 5 6 2 6 1 3 5 1] Now I would like to get the index of the minimum values in this vector. When...

13 years ago

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Vectorize the digits of an Integer
Create a vector of length N for an integer of N digits. x=123045; x_vec=[1 2 3 0 4 5]; I happened upon a trick to do ...

13 years ago

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Set defaults
Write a function that computes the volume of a cube. The function should be able to accept three inputs: the length, width, and...

13 years ago

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Return unique values without sorting
If the input vector A is [42 1 1], the output value B must be the unique values [42 1] The *values of B are in the s...

13 years ago

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First non-zero element in each column
For a given matrix, calculate the index of the first non-zero element in each column. Assuming a column with all elements zero ...

13 years ago

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Specific Element Count
Given a vector _v_ and a element _e_, return the number of occurrences of _e_ in _v_. Note: NaNs are equal and there may be n...

13 years ago