37 total contributions since 2015

Consultant, math geek.

Answered

variable sine wave for DAC

x=[0:.01:1000] y=x/2pi %or whatever frequency modulation you want z=sin(x)

variable sine wave for DAC

x=[0:.01:1000] y=x/2pi %or whatever frequency modulation you want z=sin(x)

bijna 2 jaar ago | 0

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.

meer dan 3 jaar 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...

meer dan 3 jaar 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...

meer dan 3 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar 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...

bijna 4 jaar ago

Solved

Test for balanced parentheses

Given the input inStr, give the boolean output out indicating whether all the parentheses are balanced. Examples: * If ...

bijna 4 jaar 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. Examp...

bijna 4 jaar ago

Solved

Feeling lucky?

Guess which number Cody is thinking (1 to 10)? (This is a game of luck more than skill. Good luck!)

bijna 4 jaar ago

Solved

Free passes for everyone!

_Simply return the name of the coolest numerical computation software ever_ *Extra reward* (get a _freepass_): As an addit...

bijna 4 jaar ago

Solved

Indexed Probability Table

This question was inspired by a Stack Overflow question forwarded to me by Matt Simoneau. Given a vector x, make an indexed pro...

bijna 4 jaar ago

Solved

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...

bijna 4 jaar ago

Solved

Pattern matching

Given a matrix, m-by-n, find all the rows that have the same "increase, decrease, or stay same" pattern going across the columns...

bijna 4 jaar ago

Solved

Reverse Run-Length Encoder

Given a "counting sequence" vector x, construct the original sequence y. A counting sequence is formed by "counting" the entrie...

bijna 4 jaar ago

Solved

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...

bijna 4 jaar ago

Solved

Binary numbers

Given a positive, scalar integer n, create a (2^n)-by-n double-precision matrix containing the binary numbers from 0 through 2^n...

bijna 4 jaar ago

Solved

Replace NaNs with the number that appears to its left in the row.

Replace NaNs with the number that appears to its left in the row. If there are more than one consecutive NaNs, they should all ...

bijna 4 jaar 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 ...

bijna 4 jaar ago

Solved

Find the alphabetic word product

If the input string s is a word like 'hello', then the output word product p is a number based on the correspondence a=1, b=2, ....

ongeveer 4 jaar 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...

ongeveer 4 jaar ago

Solved

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...

ongeveer 4 jaar ago

Solved

Distance walked 1D

Suppose you go from position 7 to 10 to 6 to 4. Then you have walked 9 units of distance, since 7 to 10 is 3 units, 10 to 6 is 4...

ongeveer 4 jaar 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...

ongeveer 4 jaar ago

Solved

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 ...

ongeveer 4 jaar ago