78 total contributions since 2009

Professional Interests: Audio, signal processing

Solved

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 ...

8 years ago

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It dseon't mettar waht oedrr the lrettes in a wrod are.

An internet meme from 2003 (read more <http://www.snopes.com/language/apocryph/cambridge.asp here>) asserted that readers are re...

8 years ago

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Find relatively common elements in matrix rows

You want to find all elements that exist in greater than 50% of the rows in the matrix. For example, given A = 1 2 3 5 ...

8 years ago

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Renaming a field in a structure array

MATLAB has a <http://www.mathworks.com/help/techdoc/ref/setfield.html setfield> and a <http://www.mathworks.com/help/techdoc/ref...

8 years ago

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All your base are belong to us

Find the base _b_ logarithm of the input decimal number _x_. Express the output as a decimal number. The first argument is the n...

8 years ago

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Remove NaN ?

input -> matrix (n*m) with at least one element equal to NaN; output -> matrix(p*m), the same matrix where we deleted the enti...

8 years ago

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Remove DC

Input x is the sampled signal vector, may have both AC and DC components. Output y should not contain any DC component. Examp...

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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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...

8 years ago

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Summing Digits within Text

Given a string with text and digits, add all the numbers together. Examples: Input str = '4 and 20 blackbirds baked in a...

8 years ago

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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, ...

8 years ago

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Given an unsigned integer x, find the largest y by rearranging the bits in x

Given an unsigned integer x, find the largest y by rearranging the bits in x. Example: Input x = 10 Output y is 12 ...

8 years ago

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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...

8 years ago

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Extract leading non-zero digit

<http://en.wikipedia.org/wiki/Benford%27s_law Benford's Law> states that the distribution of leading digits is not random. This...

8 years ago

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De-dupe

Remove all the redundant elements in a vector, but keep the first occurrence of each value in its original location. So if a =...

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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Balanced number

Given a positive integer find whether it is a balanced number. For a balanced number the sum of first half of digits is equal to...

8 years ago

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Is my wife right? Now with even more wrong husband

Again, as in "Is my wife right?" ( <http://www.mathworks.com/matlabcentral/cody/problems/149-is-my-wife-right> ), answer 'yes' r...

8 years ago

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Too mean-spirited

Find the mean of each consecutive pair of numbers in the input row vector. For example, x=[1 2 3] ----> y = [1.5 2.5] x=[1...

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

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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...

8 years 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]

8 years ago

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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...

8 years ago

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Pizza!

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

8 years ago

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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...

8 years ago

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Word Counting and Indexing

You are given a list of strings, each being a list of words divided by spaces. Break the strings into words, then return a maste...

8 years ago

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Biggest Value in the (Neighbor)Hood

For this challenge you get two inputs: a matrix A and an integer value n. Your function should return a Matrix B of the same si...

9 years ago

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N-Dimensional Array Slice

Given an N-dimensional array, _A_, an index, _I_, and a dimension, _d_, return the _I_ th elements of _A_ in the _d_ dimension. ...

9 years ago