Community Profile

# John Booker

### MathWorks

22 total contributions since 2011

I'm a user experience specialist at MathWorks where I get to do a lot of fun things. The big two are: making MATLAB easier to use, and helping MATLAB Central to better serve the community.
Professional Interests: gamification, information visualization, user experience

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Solved

Check if sorted
Check if sorted. Example: Input x = [1 2 0] Output y is 0

mehr als 5 Jahre ago

Solved

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...

etwa 6 Jahre ago

Solved

Simple problem creating a function from an abstract specification.
MYSTERYFUNCTION3 This takes a vector of numbers v and computes a vector w such the w[i] is the average of v[i] and the previous...

etwa 6 Jahre ago

Solved

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...

etwa 6 Jahre ago

Solved

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

mehr als 6 Jahre ago

Solved

Pizza!
Given a circular pizza with radius _z_ and thickness _a_, return the pizza's volume. [ _z_ is first input argument.] Non-scor...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre 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...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

Is my wife right?
Regardless of input, output the string 'yes'.

mehr als 6 Jahre ago

Solved

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 ...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

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

mehr als 6 Jahre 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 ...

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

Determine if input is odd
Given the input n, return true if n is odd or false if n is even.

mehr als 6 Jahre ago

Solved

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...

mehr als 6 Jahre ago

Solved

Find the sum of all the numbers of the input vector
Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

fast 7 Jahre ago

Solved

Times 2 - START HERE
Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

fast 7 Jahre ago

Question

How to extract leading non-zero digit?
I'm working on a research problem related to Benford's Law which states that the distribution of leading digits is not random. T...

mehr als 8 Jahre ago | 4 answers | 6