Problem

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 ...

14 years ago | 0 | 104 solvers

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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 ...

14 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...

14 years ago

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Symmetric matrix
You must create a n-by-n *symmetric* matrix such that A(row,col) = row/col for col >= row. Example if n =3 : output is : ...

14 years ago

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Project Euler: Problem 4, Palindromic numbers
A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 ...

14 years ago

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

14 years ago

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Rosenbrock's Banana Function and its derivatives
Write a function to return the value of <http://en.wikipedia.org/wiki/Rosenbrock_function Rosenbrock's two-dimensional banana fu...

14 years ago

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Convert a numerical matrix into a cell array of strings
Given a numerical matrix, output a *cell array of string*. For example: if input = 1:3 output is {'1','2','3'} whic...

14 years ago

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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...

14 years ago

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Function composition
Write a function that accepts two function handles f and g and returns the composition h. That is, h = (f o g)(x) = f(g(x)) ...

14 years ago

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Check if number exists in vector
Return 1 if number _a_ exists in vector _b_ otherwise return 0. a = 3; b = [1,2,4]; Returns 0. a = 3; b = [1,...

14 years ago

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Back to basics 3 - Temp Directory
Covering some basic topics I haven't seen elsewhere on Cody. Return a string that is the path to the system's current temp di...

14 years ago

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Half?
If you toss an even number (x) of coins, what is the probability (y) of 50% head and 50% tail?

14 years ago

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Back to basics 15 - classes
Covering some basic topics I haven't seen elsewhere on Cody. Return the class of the input variable.

14 years ago

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Set defaults
Write a function that computes the volume of a cube. The function should be able to accept three inputs: the length, width, and...

14 years ago

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Set some matrix elements to zero
First get the maximum of each *row*, and afterwards set all the other elements to zero. For example, this matrix: 1 2 3 ...

14 years ago

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What are the odds?
Two numbers, A and B are drawn randomly and uniformly on [-R,R]. What is the probability that A*B < A+B. Your function should ...

14 years ago

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Make a random, non-repeating vector.
This is a basic MATLAB operation. It is for instructional purposes. --- If you want to get a random permutation of integer...

14 years ago

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Vectorize the digits of an Integer
Create a vector of length N for an integer of N digits. x=123045; x_vec=[1 2 3 0 4 5]; I happened upon a trick to do ...

14 years ago

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Cannon Ball
Given g (acceleration due to gravity) and desired altitude x, find the minimum ground velocity of a cannon ball to reach x.

14 years ago

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Make an N-dimensional Multiplication Table
*INSTRUCTIONS* This is a multi-dimensional variant of the normal multiplication table used to teach elementary students multi...

14 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: ...

14 years ago

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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 ago

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Getting logical indexes
This is a basic MATLAB operation. It is for instructional purposes. --- Logical indexing works like this. thresh = 4...

14 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...

14 years ago

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Circumscribed circles
Given the lengths of the 3 sides of a triangle, output the radius of the circumscribed circle. Example: [3 4 5] -> 2.5

14 years ago

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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. ...

14 years ago

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Arrange vector in ascending order
Arrange a given vector in ascending order. input = [4 5 1 2 9]; output = [1 2 4 5 9];

14 years ago

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Rotate a Matrix
Input a Matrix x, Output y is the matrix rotating x 90 degrees clockwise

14 years ago

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

14 years ago