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Sum of series I
What is the sum of the following sequence: Σ(2k-1) for k=1...n for different n?

4 years ago

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Create a vector whose elements depend on the previous element
The idea is to create a vector A whose elements depend on the previous element : *A(i+1) = 2*A(i)+1* *2 Inputs*: - A : The...

4 years ago

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Create an index-powered vector
Given a input vector x, return y as index-powered vector as shown below. Example x = [2 3 6 9] then y should be [...

4 years ago

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Which values occur exactly three times?
Return a list of all values (sorted smallest to largest) that appear exactly three times in the input vector x. So if x = [1 2...

4 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...

4 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...

4 years ago

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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 ...

4 years ago

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Project Euler: Problem 8, Find largest product in a large string of numbers
Find the greatest product of five consecutive digits in an n-digit number. 73167176531330624919225119674426574742355349194934...

4 years ago

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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...

4 years ago

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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 ...

4 years ago

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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...

4 years ago

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Find x rows where the sum of the numbers is the maximum

4 years ago

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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...

4 years ago

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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...

4 years ago

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Remove any row in which a NaN appears
Given the matrix A, return B in which all the rows that have one or more <http://www.mathworks.com/help/techdoc/ref/nan.html NaN...

4 years ago

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Project Euler: Problem 5, Smallest multiple
2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder. What is the smalle...

4 years ago

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Create a matrix X, where each column is a shifted copy of the vector v
Example : in->v = (1:5)'; 1 2 3 4 5 out-> [1 5 4 3 2;2 1 5 4 3;3 2 1 5 4;4 3 2 1 5;5 4 3 ...

4 years ago

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Symmetric matrix
You must create a n-by-n *symmetric* matrix such that A(row,col) = row/col for col >= row. Example if n =3 : output is : ...

4 years ago

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Bullseye Matrix
Given n (always odd), return output a that has concentric rings of the numbers 1 through (n+1)/2 around the center point. Exampl...

4 years ago

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Counting in Finnish
Sort a vector of single digit whole numbers alphabetically by their name, in Finnish. See the Wikipedia page for <http://en.wik...

4 years ago

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Return the largest number that is adjacent to a zero
This example comes from Steve Eddins' blog: <http://blogs.mathworks.com/steve/2009/05/27/learning-lessons-from-a-one-liner/ Lear...

4 years ago

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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...

4 years ago

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Project Euler: Problem 4, Palindromic numbers
A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 ...

4 years ago

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Mandelbrot Numbers
The <http://en.wikipedia.org/wiki/Mandelbrot_set Mandelbrot Set> is built around a simple iterative equation. z(1) = c z...

4 years ago

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Binary numbers
Given a positive, scalar integer n, create a (2^n)-by-n double-precision matrix containing the binary numbers from 0 through 2^n...

4 years ago

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Pascal's Triangle
Given an integer n >= 0, generate the length n+1 row vector representing the n-th row of <http://en.wikipedia.org/wiki/Pascals_t...

4 years ago

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Find relatively common elements in matrix rows
You want to find all elements that exist in greater than 50% of the rows in the matrix. For example, given A = 1 2 3 5 ...

4 years ago

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Nearest Numbers
Given a row vector of numbers, find the indices of the two nearest numbers. Examples: [index1 index2] = nearestNumbers([2 5 3...

4 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...

4 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...

4 years ago