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Multiply a column by a row
* Given a column vector C and and a row vector R. * Output a matrix M. * Every column of M equals to C multiplied by correspon...

14 years 前

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Nilpotent matrix
Check if matrix A is <http://mathworks.com/ nilpotent>.

14 years 前

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Back to basics 6 - Column Vector
Covering some basic topics I haven't seen elsewhere on Cody. Given an input vector, output true or false whether it is a colu...

14 years 前

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edge detection
write a function that gives the indexes of rising or falling edge x is a vector (assume it contains always at least one eleme...

14 years 前

问题

edge detection
write a function that gives the indexes of rising or falling edge x is a vector (assume it contains always at least one eleme...

14 years 前 | 1 | 102 个解题者

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surrounded matrix
With a given matrix A (size m x n) create a matrix B (size m+2 x n+2) so that the matrix A is surrounded by ones: A = [1 2 ...

14 years 前

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Whether the input is vector?
Given the input x, return 1 if x is vector or else 0.

14 years 前

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Is A the inverse of B?
Given a matrix A and a matrix B, is A the inverse of B? >>A=[2,4;3,5]; >>B=[-2.5,2;1.5,-1]; >>isInverse...

14 years 前

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Matrix indexing with two vectors of indices
Given a matrix M and two index vectors a and b, return a row vector x where x(i) = M(a(i),b(i)).

14 years 前

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Retirement savings
At the start of what year will you have reached or exceeded a savings goal? Parameters (all are constant scalars given in a s...

14 years 前

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"Look and say" sequence
What's the next number in this sequence? * [0] * [1 0] * [1 1 1 0] * [3 1 1 0] * [1 3 2 1 1 0] This a variant on the w...

14 years 前

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Reduce - Map-Reduce
Write reduce function, that takes arguments and constantly folds results into next call argument, finally returning a value; ...

14 years 前

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Find the numeric mean of the prime numbers in a matrix.
There will always be at least one prime in the matrix. Example: Input in = [ 8 3 5 9 ] Output out is 4...

14 years 前

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middleAsColumn: Return all but first and last element as a column vector
Given input A, return all but the first and last elements, arranged as a column vector. (I.e., all dimensions after the first s...

14 years 前

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Formatting currency numbers
Given a number, format it properly for textual display using the notation $xxx,xxx,xxx.xx. Assume that no more than two digits ...

14 years 前

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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.

14 years 前

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Number of 1s in a binary string
Find the number of 1s in the given binary string. Example. If the input string is '1100101', the output is 4. If the input stri...

14 years 前

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Return elements unique to either input
Given two numeric inputs a and b, return a row vector that contains the numbers found in only a or only b, but not both. For ex...

14 years 前

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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 =...

14 years 前

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Find the largest value in the 3D matrix
Given a 3D matrix, A, find the largest value. E.g. >> A = 1:9; >> A=reshape(A,[3 1 3]); >> islargest(A) ans = 9

14 years 前

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Cody Computer Part 2 - Get the license number of Cody Computer
In the Cody computer investigation party, you may have already solved : <http://www.mathworks.com/matlabcentral/cody/problems...

14 years 前

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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 ...

14 years 前

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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...

14 years 前

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Vectorizing, too easy or too hard?
Please insert a . before any ^, * or / in the string. That's it!!

14 years 前

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Flip the main diagonal of a matrix
Given a n x n matrix, M, flip its main diagonal. Example: >> M=magic(5); >> flipDiagonal(M) 9 24 1 ...

14 years 前

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Sum of first n terms of a harmonic progression
Given inputs a, d and n, return the sum of the first n terms of the harmonic progression a, a/(1+d), a/(1+2d), a/(1+3d),....

14 years 前

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"Low : High - Low : High - Turn around " -- Create a subindices vector
Let two vectors *lo* and *hi* be given. The job is to create a index vector like so idx = [lo(1):hi(1) lo(2):hi(2) ...]...

14 years 前

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Create a square matrix of multiples
Given an input, N, output a matrix N x N with each row containing multiples of the first element of each row. This also applies...

14 years 前

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Is the Point in a Circle?
Check whether a point or multiple points is/are in a circle centered at point (x0, y0) with radius r. Points = [x, y]; c...

14 years 前

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What is the distance from point P(x,y) to the line Ax + By + C = 0?
Given a point, P(x,y), find the distance from this point to a linear line. INPUTS: x, y, A, B, C OUTPUTS: d, the distance ...

14 years 前