I love MATLAB. I love teaching people to love MATLAB.

I love it so much that I went to work for the people who make MATLAB. I spend my days at MathWorks creating material to help people learn MATLAB. Life is good.

(My love of teaching MATLAB notwithstanding, please don't email me for help -- post a question to MATLAB Answers instead. Firstly, your email will probably be swallowed by my spam filter. Secondly, private consulting isn't in my job description.)

Solved

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 days 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.

7 days ago

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Make a random, non-repeating vector.

This is a basic MATLAB operation. It is for instructional purposes. --- If you want to get a random permutation of integer...

7 days ago

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Roll the Dice!

*Description* Return two random integers between 1 and 6, inclusive, to simulate rolling 2 dice. *Example* [x1,x2] =...

7 days ago

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Number of 1s in a binary string

Find the number of 1s in the given binary string. Example. If the input string is '1100101', the output is 4. If the input stri...

7 days ago

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Return the first and last character of a string

Return the first and last character of a string, concatenated together. If there is only one character in the string, the functi...

7 days 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...

7 days ago

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Getting the indices from a vector

This is a basic MATLAB operation. It is for instructional purposes. --- You may already know how to <http://www.mathworks....

7 days ago

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Check if number exists in vector

Return 1 if number _a_ exists in vector _b_ otherwise return 0. a = 3; b = [1,2,4]; Returns 0. a = 3; b = [1,...

7 days 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...

7 days 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...

7 days 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 = ...

7 days 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]

7 days ago

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Length of the hypotenuse

Given short sides of lengths a and b, calculate the length c of the hypotenuse of the right-angled triangle. <<http://upload....

7 days ago

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Generate a vector like 1,2,2,3,3,3,4,4,4,4

Generate a vector like 1,2,2,3,3,3,4,4,4,4 So if n = 3, then return [1 2 2 3 3 3] And if n = 5, then return [1 2 2...

7 days 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...

7 days ago

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Maximum value in a matrix

Find the maximum value in the given matrix. For example, if A = [1 2 3; 4 7 8; 0 9 1]; then the answer is 9.

7 days ago

Answered

Kullback-Leibler Divergence for NMF in Matlab

If X and X_hat are just matrices, then I think you should be able to compute all the terms element-wise and sum the result (unle...

Kullback-Leibler Divergence for NMF in Matlab

If X and X_hat are just matrices, then I think you should be able to compute all the terms element-wise and sum the result (unle...

3 months ago | 0

| accepted

Answered

Extract multiple data points from matrix

It might help to know a bit more about what you're actually trying to do. Given that you're indexing with (:,k), it seems that t...

Extract multiple data points from matrix

It might help to know a bit more about what you're actually trying to do. Given that you're indexing with (:,k), it seems that t...

3 months ago | 0

Solved

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...

7 months ago

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Project Euler: Problem 7, Nth prime

By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13. What is the Nth prime nu...

7 months ago

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Project Euler: Problem 10, Sum of Primes

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17. Find the sum of all the primes below the input, N. Thank you <http:/...

7 months ago

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Project Euler: Problem 2, Sum of even Fibonacci

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 te...

7 months ago

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Project Euler: Problem 6, Natural numbers, squares and sums.

The sum of the squares of the first ten natural numbers is, 1^2 + 2^2 + ... + 10^2 = 385 The square of the sum of the first ...

7 months ago

Solved

Project Euler: Problem 1, Multiples of 3 and 5

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23...

7 months 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...

1 year ago

Answered

How to find average score of different combination

Can you explain what you mean by "same" and "different" in this context, and how you're getting the output you want, because it'...

How to find average score of different combination

Can you explain what you mean by "same" and "different" in this context, and how you're getting the output you want, because it'...

1 year ago | 0

Solved

ASCII Birthday Cake

Given an age and a name, give draw an ASCII birthday cake. For example, given the name "CODY" and the age 5, return a string wit...

1 year ago

Solved

MATLAB Counter

Write a function f = counter(x0,b) to construct a counter handle f that counts with an initial value x0 and a step size b. E...

1 year ago