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Is A the inverse of B?
Given a matrix A and a matrix B, is A the inverse of B? >>A=[2,4;3,5]; >>B=[-2.5,2;1.5,-1]; >>isInverse...

13 years ago

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Sums with Excluded Digits
Add all the integers from 1 to n in which the digit m does not appear. m will always be a single digit integer from 0 to 9. no...

13 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...

13 years ago

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How to find the position of an element in a vector without using the find function
Write a function posX=findPosition(x,y) where x is a vector and y is the number that you are searching for. Examples: fin...

13 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 ...

13 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...

13 years ago

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Add two numbers
Given a and b, return the sum a+b in c.

13 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...

13 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 ...

13 years ago

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Make the vector [1 2 3 4 5 6 7 8 9 10]
In MATLAB, you create a vector by enclosing the elements in square brackets like so: x = [1 2 3 4] Commas are optional, s...

13 years ago

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Summing digits
Given n, find the sum of the digits that make up 2^n. Example: Input n = 7 Output b = 11 since 2^7 = 128, and 1 + ...

13 years ago

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Reverse the vector
Reverse the vector elements. Example: Input x = [1,2,3,4,5,6,7,8,9] Output y = [9,8,7,6,5,4,3,2,1]

13 years ago

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Replace Vector Elements
Replace all elements in a vector which are equal to or smaller than zero with 0.1. Example: A = [1 2 3 -1 0 2 -3 -80]; ...

13 years ago

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The Goldbach Conjecture
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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Sorted highest to lowest?
Return 1 if the input is sorted from highest to lowest, 0 if not. Example: 1:7 -> 0 [7 5 2] -> 1

13 years ago

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Proper Factors
Generate the proper factors of input integer _x_ and return them in ascending order. For more information on proper factors, ref...

13 years ago

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Determine if a Given Number is a Triangle Number
*Description:* Determine if the elements of an input array are triangle numbers and return the result as an array with the sa...

13 years ago

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Triangle Numbers Below N
This is an offshoot of <http://www.mathworks.com/matlabcentral/cody/problems/5-triangle-numbers Cody Problem 5: Triangle Numbers...

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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inner product of two vectors
inner product of two vectors

13 years ago

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Swap the input arguments
Write a two-input, two-output function that swaps its two input arguments. For example: [q,r] = swap(5,10) returns q = ...

13 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...

13 years ago

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Too mean-spirited
Find the mean of each consecutive pair of numbers in the input row vector. For example, x=[1 2 3] ----> y = [1.5 2.5] x=[1...

13 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.

13 years ago

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Target sorting
Sort the given list of numbers |a| according to how far away each element is from the target value |t|. The result should return...

13 years ago

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Create times-tables
At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 times 12 is way more th...

13 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...

13 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 ...

13 years ago

Solved

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...

13 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...

13 years ago