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Error using wswor: The algorithm used for weighted selection without replacement has unexpectedly failed.

Hey everyone, I am using the datasample function in a rather big algorithm which is executed on a cluster. It fails relativel...

5 years ago | 0 answers | 0

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How to determine the height of normal distribution fit from e.g. hitfit

Hello Daniel, The integral over the normal distribution (=:dist1) from minus infinity to infinity is 1. The integral over th...

How to determine the height of normal distribution fit from e.g. hitfit

Hello Daniel, The integral over the normal distribution (=:dist1) from minus infinity to infinity is 1. The integral over th...

6 years ago | 1

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The Hitchhiker's Guide to MATLAB

Output logical "true" if the input is the answer to life, the universe and everything. Otherwise, output logical "false".

7 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.

7 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...

7 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...

7 years ago

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Given a window, how many subsets of a vector sum positive

Given a vector: [1 0 -1 3 2 -3 1] and a window of 2, A sliding window would find: 1 + 0 = 1 0 - 1 = -1 ...

7 years ago

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How many trades represent all the profit?

Given a list of results from trades made: [1 3 -4 2 -1 2 3] We can add them up to see this series of trades made a profit ...

7 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...

8 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...

8 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...

8 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 ...

8 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...

8 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...

8 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...

8 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...

8 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 ...

8 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...

8 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...

8 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...

8 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...

8 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...

8 years ago

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Making change

Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

8 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 ...

8 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 ...

8 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...

8 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...

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...

8 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...

8 years ago