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Create a vector whose elements depend on the previous element
The idea is to create a vector A whose elements depend on the previous element : *A(i+1) = 2*A(i)+1* *2 Inputs*: - A : The...

13 years ago

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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...

13 years ago

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Sum the entries of each column of a matrix which satisfy a logical condition.
Given a numeric matrix A and a logical array L of the same size as A, return a row vector S containing the columnwise sums of th...

13 years ago

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Cell joiner
You are given a cell array of strings and a string delimiter. You need to produce one string which is composed of each string fr...

13 years ago

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Back to basics 9 - Indexed References
Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix and row and column, output the index of th...

13 years ago

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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.

13 years ago

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Replace all zeros and NaNs in a matrix with the string 'error'
Given a numeric input matrix A, possibly containing some zero values and some NaNs, replace any occurrences of zero or NaN with ...

13 years ago

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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

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Right and wrong
Given a vector of lengths [a b c], determines whether a triangle with those sides lengths is a right triangle: <http://en.wikipe...

13 years ago

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Multiply 2 numbers
Very easy, you just have to multiply 2 numbers but you cannot use the following signs (*, /, - ,^) ,mtimes , times, cross, pro...

13 years ago

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Check if sorted
Check if sorted. Example: Input x = [1 2 0] Output y is 0

13 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]

13 years ago

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Remove the air bubbles
Given a matrix a, return a matrix b in which all the zeros have "bubbled" to the top. That is, any zeros in a given column shoul...

13 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...

13 years ago

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Is my wife right?
Regardless of input, output the string 'yes'.

13 years ago

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Are all the three given point in the same line?
In this problem the input is the coordinate of the three points in a XY plane? P1(X1,Y1) P2(X2,Y2) P3(X3,Y3) how can...

13 years ago

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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...

13 years ago

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Change a specific color in an image
The ability to change colors can be a useful tool in image processing. Given an m x n x 3 array (much like CData in images), fin...

13 years ago

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Back and Forth Rows
Given a number n, create an n-by-n matrix in which the integers from 1 to n^2 wind back and forth along the rows as shown in the...

13 years ago

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Matrix with different incremental runs
Given a vector of positive integers a = [ 3 2 4 ]; create the matrix where the *i* th column contains the vector *1:a(i)...

13 years ago

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Set the array elements whose value is 13 to 0
Input A either an array or a vector (which can be empty) Output B will be the same size as A . All elements of A equal to 13...

13 years ago

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Getting the indices from a matrice
Getting the indices from a matrice. Inspired by Problem 645. Getting the indices from a vector by the great Doug Hull. Given a...

13 years ago

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Fill a zeros matrix
The aim is to fill an array of all zeros given a numerical value and the index of row and columns for this value. 3 Inputs: ...

13 years ago

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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 ...

13 years ago

Solved

Back to basics 23 - Triangular matrix
Covering some basic topics I haven't seen elsewhere on Cody. Given an input matrix, return a matrix with all elements above a...

13 years ago

Answered
total number of elements which are not zero
Hi, what about: B = sum(Percey~=0,2); Regards, W.

13 years ago | 0

| accepted

Problem

Index of neighbor pixel with steepest gradient
Unlike in various applications, where the gradient of a two dimensional matrix is calculated in x and y direction, the gradient ...

13 years ago | 2 | 28 solvers

Answered
How can I perform a comparison function (of surrounding pixels) on a DEM using a starting pixel?
Hi, you might be interested in using the function ixneighbors available on the FEX which might make life a little easier for ...

13 years ago | 0

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...

13 years ago

Solved

Select every other element of a vector
Write a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...

13 years ago