# Geoff McVittie

### MathWorks

Followers: 0 Following: 0

**Statistics**

RANK**5,086**

of 295,024

REPUTATION**10**

CONTRIBUTIONS

**0** Questions

**5** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**1**

RANK**3,818** of 20,166

REPUTATION**379**

AVERAGE RATING**4.80**

CONTRIBUTIONS**3** Files

DOWNLOADS **22**

ALL TIME DOWNLOADS**2467**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Feeds**

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.

10 years ago

Solved

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...

10 years ago

Solved

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...

10 years ago

Solved

Is this triangle right-angled?

Given three positive numbers a, b, c, where c is the largest number, return *true* if the triangle with sides a, b and c is righ...

10 years ago

Solved

Remove the vowels

Remove all the vowels in the given phrase. Example: Input s1 = 'Jack and Jill went up the hill' Output s2 is 'Jck nd Jll wn...

10 years ago

Solved

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...

10 years 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...

10 years 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...

10 years ago

Solved

Pangrams!

A pangram, or holoalphabetic sentence, is a sentence using every letter of the alphabet at least once. Example: Input s ...

10 years ago

Solved

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...

10 years ago

Solved

Cell joiner

You are given a cell array of strings and a string delimiter. You need to produce one string which is composed of each string fr...

10 years ago

Solved

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]

10 years ago

Solved

Elapsed Time

Given two date strings d1 and d2 of the form yyyy/mm/dd HH:MM:SS (assume hours HH is in 24 hour mode), determine how much time, ...

10 years 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...

10 years ago

Solved

Roll the Dice!

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

10 years ago

Solved

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...

10 years ago

Solved

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 + ...

10 years 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...

10 years 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...

10 years 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...

10 years ago

Solved

Who Has the Most Change?

You have a matrix for which each row is a person and the columns represent the number of quarters, nickels, dimes, and pennies t...

10 years 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...

10 years 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...

10 years ago

Solved

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...

10 years 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 ...

10 years 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...

10 years 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...

10 years 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 ...

10 years ago