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Gauss Eliminate 2-by-2 example

Use forward elimination to make the coefficient matrix, A, an upper triangular matrix, and then solve using back substitution, f...

11 years ago

Solved

REPMAT Enhancement - Faster for Large Row Replication of Vector

The Challenge is to modify repmat.m to maintain all of its normal functionality and enhance its performance for large row replic...

11 years ago

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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...

11 years ago

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Find: Faster Alternatives for Large Sorted/Unique Vectors

The Challenge is to create faster Find methods for large unique ascending vectors. Methods exist that are 1000 times faster t...

11 years ago

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sum of non-primes

The sum of the non-primes below 10 is 1+4+6+8+9+10=38 Find the sum of all the non-primes below the input, N.

11 years ago

Solved

Make a logical diamond using GALLERY function

Inspired from <http://www.mathworks.com/matlabcentral/cody/problems/1078-make-a-diamond Problem 1078. Make a diamond> In thi...

11 years ago

Problem

Make a logical diamond using GALLERY function

Inspired from <http://www.mathworks.com/matlabcentral/cody/problems/1078-make-a-diamond Problem 1078. Make a diamond> In thi...

11 years ago | 5 | 95 solvers

Solved

Colon operator of two vectors

You are given two vectors of equal length: VecStart, VecEnd Each vector contain a set of integers, where VecEnd(j)>=VecStar...

11 years ago

Solved

Lychrel Number Test (Inspired by Project Euler Problem 55)

The task for this problem is to create a function that takes a number _n_ and tests if it might be a Lychrel number. This is, re...

11 years ago

Solved

Circular Primes (based on Project Euler, problem 35)

The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime. The...

11 years ago

Solved

Steal, Share, or Catch

You, I, and a few other characters are going to play a game of *Steal, Share or Catch*. We are going to play it 10,000 times vs...

11 years ago

Solved

Pi Estimate 1

Estimate Pi as described in the following link: <http://www.people.virginia.edu/~teh1m/cody/Pi_estimation1.pdf>

12 years ago

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Phoneword Translator

Given an alphanumeric telephone number (Ex. 1-800-COLLECT), return the purely numeric phone number as a vector. This problem use...

12 years ago

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Next Lower Power of B

Given a number _n_ and a base _B_ greater than 1, return the lowest integer power of _B_ that is less than or equal to _n_. E...

12 years ago

Solved

Next Higher Power of B

|Given a number _n_ and a base _B_ greater than 1, return the lowest integer power of _B_ that is greater than or equal to _n_. ...

12 years ago

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Multiples of a Number in a Given Range

Given an integer factor _f_ and a range defined by _xlow_ and _xhigh_ inclusive, return a vector of the multiples of _f_ that fa...

12 years ago

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Largest Twin Primes

<http://en.wikipedia.org/wiki/Twin_prime Twin primes> are primes p1, p2 = p1 + 2 such that both p1 and p2 are prime numbers. Giv...

12 years ago

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The Dark Side of the Die

It is well-known that opposite sides of a classic hexahedral die add to 7. Given a vector of dice rolls, calculate the sum of th...

12 years ago

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Rank of magic square (for beginners)

Compute the rank r of a magic square of order n WITHOUT rank and magic functions.

12 years ago

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Given a matrix, return the last eigen value

Given a matrix, return the first eigen value For example: x = magic(5) 17 24 1 8 15 23 5 7 14 ...

12 years ago

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Test if two numbers have the same digits

Given two integers _x1_ and _x2_, return |true| if the numbers written with no leading zeros contain the same digits. That is, t...

12 years ago

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Guess Cipher

Guess the formula to transform strings as follows: 'Hello World!' --> 'Ifmmp Xpsme!' 'Can I help you?' --> 'Dbo J ifmq zpv...

12 years ago

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Television Screen Dimensions

Given a width to height ratio of a TV screen given as _w_ and _h_ as well as the diagonal length of the television _l_, return t...

12 years ago

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Magic is simple (for beginners)

Determine for a magic square of order n, the magic sum m. For example m=15 for a magic square of order 3.

12 years ago

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Detect a number and replace with two NaN's

Write code which replaces the number 1 with two NaNs. Example X = [ 1 2 NaN 4 1 3 7 NaN 1 4 NaN 2] ...

12 years ago

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Elapsed time is -0.005204 seconds.

Write a function that takes less than zero seconds to execute, as measured using tic and toc. For repeatability, the test case p...

12 years ago

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Make a 1 hot vector

Make a vector of length _N_ that consists of all zeros except at index _k_, where it has the value 1. Example: Input ...

12 years ago

Solved

Create a Multiplication table matrix...

Create a product table in this format: P = [ 1 2 3 4 5; 2 4 6 8 10; 3 6 9 12 15; 4 8 12 1...

12 years ago

Solved

Cell Counting: How Many Draws?

You are given a cell array containing information about a number of soccer games. Each cell contains one of the following: * ...

12 years ago