Alan Chalker

Ohio Supercomputer Center

283 total contributions since 2009

Alan Chalker's Badges

Solved

Dick Van Dyck?
* Not the celebrity, <http://en.wikipedia.org/wiki/Dick_Van_Dyke Dick Van Dyke>, * this problem relates to balanced strings of...

8 years ago

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Compress strings (not springs)
Please remove excess space, limit one space between others, and no space before punctuation marks. * For example, 'Trendy , ...

8 years ago

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Mr. Pyramidad & Ms. Whissy Bolower
Businessman Mr. B. M. Pyramidad was drinking with his new girlfriend Ms. Whissy Bolower. He disclosed to her that he has an ille...

8 years ago

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Aufbau principle
Given the order e=[1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p], find a vector x with these condi...

8 years ago

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Surface Fit z(x,y)
Given three vectors x,y,z. Find four coefficients c = [cxx cxy cyy c00], such that z = cxx*x.^2+cxy*x.*y+cyy*y.^2+c00. For e...

8 years ago

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Bang Bang in Bangalore
Imagine a strange language disorder, Bangolangosis, has developed among trigonometricians of <http://en.wikipedia.org/wiki/Banga...

8 years ago

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Find the Kronecker Tensor Product without using KRON
The Kronecker Tensor Product is the result of multiplying all elements of a matrix with each of the elements of another matrix. ...

8 years ago

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Let's do Markov Chains!
<http://en.wikipedia.org/wiki/Markov_chain Markov Chains> are really useful in a lot of fields. This problem will ask a question...

8 years ago

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Back to basics 26 - Keywords
Covering some basic topics I haven't seen elsewhere on Cody. Return a cell array of strings of all MATLAB keywords.

8 years ago

Problem

Back to basics 26 - Keywords
Covering some basic topics I haven't seen elsewhere on Cody. Return a cell array of strings of all MATLAB keywords.

8 years ago | 0

Solved

Back to basics 25 - Valid variable names
Covering some basic topics I haven't seen elsewhere on Cody. Given a string, return true if it is a valid MATLAB variable nam...

8 years ago

Problem

Back to basics 25 - Valid variable names
Covering some basic topics I haven't seen elsewhere on Cody. Given a string, return true if it is a valid MATLAB variable nam...

8 years ago | 1

Problem

Back to basics 24 - Symbolic variables
Covering some basic topics I haven't seen elsewhere on Cody. Given a string algebraic expression, return the symbolic variabl...

8 years ago | 1

Solved

Back to basics 24 - Symbolic variables
Covering some basic topics I haven't seen elsewhere on Cody. Given a string algebraic expression, return the symbolic variabl...

8 years ago

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Sum of diagonal of a square matrix
If x = [1 2 4; 3 4 5; 5 6 7] then y should be the sum of the diagonals of the matrix y = 1 + 4 + 7 = 12

8 years ago

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Replace May with April
For instance, if the input is input_str = 'The flowers may bloom in April'; then the output is output_str = 'The flo...

8 years ago

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Make an awesome ramp for a tiny motorcycle stuntman
Okay, given a vector, say v=[1 3 6 9 11], turn it into a matrix 'ramp' like so: m=[1 3 6 9 11; 3 6 9 11 0; 6 9 ...

8 years ago

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Solve the set of simultaneous linear equations
Given this pair of simultaneous linear equations: 2x + 3y = 23 3x + 4y = 32 Find the solution set (x,y)

8 years ago

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Is this matrix orthogonal?
Given a square matrix, a, determine whether it is orthogonal. INPUT: a, a n x n matrix OUTPUT: true or false

8 years ago

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Tic Tac Toe FTW
Given a tic tac toe board: * 1 represents X * 0 represents empty. * -1 represents O It is X's move. If there is an imme...

8 years ago

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Leaking?
Graham's law states that the rate of effusion of a gas is inversely proportional to the square root of its molecular weight. A b...

8 years ago

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Acidity of vinegar and salts
Assuming: pH (potentia hydrogenii) = - log10(H+ ionic concentration in mol/Liter). For a buffer solution containing acetic acid ...

8 years ago

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Closely related?
Given a function past_records() that will report blood sugar level of two twin brothers some random number of days ago. For exam...

8 years ago

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ranch area?
Your friend has a ranch with four distinct boundary lines. Three boundary lines are ideal straight roads: (1) North Club Road, (...

8 years ago

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System of equations
Find a solution to a system of equations represented by a |n| by |n+1| matrix. For instance, [ 2 0 4; => 2*x = 4 ...

8 years ago

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Snakes on a plane
Given the dimensions of a 2-d plane, create a matrix where a "snake" of ones occupies the plane from top left to bottom right. ...

8 years ago

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Sorting
Assume that x is an n-by-2 matrix. The aim is to return the first column of x, but sorted according to the second column. Exa...

8 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. ...

8 years ago

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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...

8 years ago

Solved

Find common elements in matrix rows
Given a matrix, find all elements that exist in every row. For example, given A = 1 2 3 5 9 2 5 9 3 2 5 9 ...

8 years ago