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Column norms of a matrix
Given a matrix M, return a vector y such that for each k y(k)=norm(M(:,k)) (y(k) is the Euclidean norm of the k-th col...

13 years ago

Solved

Angle between Two Vectors
The dot product relationship, a dot b = | a | | b | cos(theta), can be used to determine the acute angle between vector a and ve...

13 years ago

Solved

commutative?
Given the handle to a binary function that takes two ordinary numbers, test if the function is commutative.

13 years ago

Answered
Filtering a matrix with different rules for each columns
Your indexing is causing the zeros. If, for example, rows 1 and 2 meet the criteria but row 3 doesn't, i = 4 on the next iterati...

13 years ago | 0

Solved

Create a random logical vector of N elements of which M are true.
Your task for tomorrow is to create a random binary (logical) vector of N elements of which M are true. For example: ran...

13 years ago

Solved

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...

13 years ago

Solved

peta to nano (x-ray)
for certain x-ray radiation, given frequency in petahertz, give wavelength in nanometer, must be accurate +/- 25%

13 years ago

Solved

Find best domino orientation
Given a list of pairs, find the orientation they should be placed in a line, such that the sum of the absolute values of the dif...

13 years ago

Solved

random picture with random colours
write a function which creates a random(x,y) matrix with random RGB colours for example create_pic(5,5) gives us a 3d matrix. ...

13 years ago

Solved

collision
several cars (n) were involved in this collision, the input matrix (vm) has n rows and two columns, first column for velocity an...

13 years ago

Solved

Replicate elements in vectors
Replicate each element of a row vector (with NaN) a constant number of times. Examples : n=2, A=[1 2 3] -> [1 1 2 2 3 3] n=0...

13 years ago

Solved

Number of Circles in a Number
Given a number, return the number of closed 'circles' in the base 10 numerical representation. Note: the number 4 has no circ...

13 years ago

Solved

Next Lower Power of B
Given a number _n_ and a base _B_ greater than 1, return the lowest integer power of _B_ that is less than or equal to _n_. E...

13 years ago

Solved

Rotate and display numbered tile
Imagine a square tile with four numbers on it, one on each edge. We will call these edges north, east, south, and west. If th...

13 years ago

Solved

Back to basics 18 - justification
Covering some basic topics I haven't seen elsewhere on Cody. Given a string with extra spaces in front and/or in back, return...

13 years ago

Solved

Triangle Numbers Below N
This is an offshoot of <http://www.mathworks.com/matlabcentral/cody/problems/5-triangle-numbers Cody Problem 5: Triangle Numbers...

13 years ago

Solved

Distance walked 3D
suppose you go from x-y-z coordinates [3,4,2] to [0,0,2] to [0,1,2] to [1,1,2], to [1,1,20] then you walked 25 units of distance...

13 years ago

Solved

Find the two most distant points
Given a collection of points, return the indices of the rows that contain the two points most distant from one another. The inpu...

13 years ago

Solved

The Goldbach Conjecture, Part 2
The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

13 years ago

Solved

Multiples of a Number in a Given Range
Given an integer factor _f_ and a range defined by _xlow_ and _xhigh_ inclusive, return a vector of the multiples of _f_ that fa...

13 years ago

Solved

The Dark Side of the Die
It is well-known that opposite sides of a classic hexahedral die add to 7. Given a vector of dice rolls, calculate the sum of th...

13 years ago

Solved

Television Screen Dimensions
Given a width to height ratio of a TV screen given as _w_ and _h_ as well as the diagonal length of the television _l_, return t...

13 years ago

Solved

Choose the best fitting dominoes
You will be given a cell array of nx2 matrices. Choose one row from each matrix. These are the ordered pairs that will be plac...

13 years ago

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Return the Fibonacci Sequence
Write a code which returns the Fibonacci Sequence such that the largest value in the sequence is less than the input integer N. ...

13 years ago

Solved

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...

13 years ago

Solved

Geometric series
Find the sum, given the first term t1, the common ratio r, and number of terms n. Examples If input t1=1, r=1, n=7 the...

13 years ago

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The Tower of Hanoi
In the <http://en.wikipedia.org/wiki/Tower_of_Hanoi Tower of Hanoi problem> with 3 rods (1, 2 & 3), the goal is to move a tower ...

13 years ago

Solved

pressure to dB?
given x ratio of pressure, find corresponding y dB

13 years ago

Solved

Lose control
Remove all characters that are below space in ASCII value.

13 years ago

Solved

Prime factor digits
Consider the following number system. Calculate the prime factorization for each number n, then represent the prime factors in a...

13 years ago