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What's the fastest way to program a matrix recursion in matlab?

Use matrix product! This code is about 10 times faster on my computer for t=(p+1):T Y(:,:,t) = A + sum(Y(:,:,(t-p...

What's the fastest way to program a matrix recursion in matlab?

Use matrix product! This code is about 10 times faster on my computer for t=(p+1):T Y(:,:,t) = A + sum(Y(:,:,(t-p...

5 years ago | 0

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Find the palindrome

Given the string a, find the longest palindromic sub-string b. So when a = 'xkayakyy'; you should return b = 'kayak';

8 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...

9 years ago

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Find the longest sequence of 1's in a binary sequence.

Given a string such as s = '011110010000000100010111' find the length of the longest string of consecutive 1's. In this examp...

9 years ago

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Remove the vowels

Remove all the vowels in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill' Output s2 is 'Jck nd Jll wn...

9 years ago

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Sort a list of complex numbers based on far they are from the origin.

Given a list of complex numbers z, return a list zSorted such that the numbers that are farthest from the origin (0+0i) appear f...

9 years ago

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Return the 3n+1 sequence for n

A Collatz sequence is the sequence where, for a given number n, the next number in the sequence is either n/2 if the number is e...

9 years ago

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Find the numeric mean of the prime numbers in a matrix.

There will always be at least one prime in the matrix. Example: Input in = [ 8 3 5 9 ] Output out is 4...

9 years ago

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Sum all integers from 1 to 2^n

Given the number x, y must be the summation of all integers from 1 to 2^x. For instance if x=2 then y must be 1+2+3+4=10.

9 years ago

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Test for balanced parentheses

Given the input inStr, give the boolean output out indicating whether all the parentheses are balanced. Examples: * If ...

9 years ago

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Scrabble Scores

Given a word, determine its score in <http://en.wikipedia.org/wiki/Scrabble Scrabble>. The input string will always be provide...

9 years ago

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Which doors are open?

There are n doors in an alley. Initially they are all shut. You have been tasked to go down the alley n times, and open/shut the...

9 years ago

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Maximum running product for a string of numbers

Given a string s representing a list of numbers, find the five consecutive numbers that multiply to form the largest number. Spe...

9 years ago

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Function Iterator

Given a handle fh to a function which takes a scalar input and returns a scalar output and an integer n >= 1, return a handle f...

9 years ago

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Back and Forth Rows

Given a number n, create an n-by-n matrix in which the integers from 1 to n^2 wind back and forth along the rows as shown in the...

9 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...

9 years ago

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Finding Perfect Squares

Given a vector of numbers, return true if one of the numbers is a square of one of the other numbers. Otherwise return false. E...

9 years ago

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Swap the first and last columns

Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

9 years ago

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Weighted average

Given two lists of numbers, determine the weighted average. Example [1 2 3] and [10 15 20] should result in 33.333...

9 years ago

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Fibonacci sequence

Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Inpu...

9 years ago

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Determine whether a vector is monotonically increasing

Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

9 years ago

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Who Has the Most Change?

You have a matrix for which each row is a person and the columns represent the number of quarters, nickels, dimes, and pennies t...

9 years ago

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Make a checkerboard matrix

Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1,1) should be 1. Example...

9 years ago

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Triangle Numbers

Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displa...

9 years ago

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Find all elements less than 0 or greater than 10 and replace them with NaN

Given an input vector x, find all elements of x less than 0 or greater than 10 and replace them with NaN. Example: Input ...

9 years ago

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Column Removal

Remove the nth column from input matrix A and return the resulting matrix in output B. So if A = [1 2 3; 4 5 6]; and ...

9 years ago

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Select every other element of a vector

Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

9 years ago

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Most nonzero elements in row

Given the matrix a, return the index r of the row with the most nonzero elements. Assume there will always be exactly one row th...

9 years ago