Question

How to set up a system of linear equations with loop and solve it?

There is a system of linear equations with 1000 equations and 1000 variables. The 1000 variables are: x(1),x(2),...,x(999),b. ...

2 years ago | 0 answers | 0

Question

How to plot a differential equation?

How to plot the differential equation (x-2/3)*f'(x)=6*f(x)-2+[5*(x-1/3)^+]-5*f(min([x+1/3,2/3]))? f(0)=0.8, x from 0 to 2...

2 years ago | 1 answer | 0

Solved

Count consecutive 0's in between values of 1

So you have some vector that contains 1's and 0's, and the goal is to return a vector that gives the number of 0's between each ...

2 years ago

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Oh Zero Zero Zero!!!

Hello all, So you have to find the largest section of zeros in a vector and then find the length of those zeros and there start...

2 years ago

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Find last zero for each column

Given a numeric array of arbitrary size, return the row index of the last zero for each column. If a column contains all nonzero...

2 years ago

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Create an n-by-n null matrix and fill with ones certain positions

The positions will be indicated by a z-by-2 matrix. Each row in this z-by-2 matrix will have the row and column in which a 1 has...

2 years ago

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Find nth maximum

Find nth maximum in a vector of integer numbers. Return NaN if no such number exists. x = [2 6 4 9 -10 3 1 5 -10]; So ...

2 years ago

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Alternating sum

Given vector x, calculate the alternating sum y = x(1) - x(2) + x(3) - x(4) + ...

2 years ago

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Change the sign of even index entries of the reversed vector

change the signs of the even index entries of the reversed vector example 1 vec = [4 -1 -2 9] ans = [9 2 -1 -4] example2...

2 years ago

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Create an index-powered vector

Given a input vector x, return y as index-powered vector as shown below. Example x = [2 3 6 9] then y should be [...

2 years ago

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Symmetry of vector

Determine whether the vector is symmetric or not (vector could be even or odd in length). For example: x = [1 2 3 3 2 1] ...

2 years ago

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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...

2 years ago

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Simple equation: Annual salary

Given an hourly wage, compute an annual salary by multiplying the wage times 40 and times 50, because salary = wage x 40 hours/w...

2 years ago

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Determine the number of odd integers in a vector

Determine the number of unique odd integers in a vector. Examples: Input x = [2 5 8 3 7 1]; Output y = 4; Inp...

2 years ago

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Generate a vector like 1,2,2,3,3,3,4,4,4,4

Generate a vector like 1,2,2,3,3,3,4,4,4,4 So if n = 3, then return [1 2 2 3 3 3] And if n = 5, then return [1 2 2...

2 years ago

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Construct an index vector from two input vectors in vectorized fashion

Create an index vector defined by two input vectors, one defining the beginnings of one or more index ranges, and the other defi...

2 years ago

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Piecewise linear interpolation

Given an Mx2 vector and a row of M-1 integers, output a two column vector that linearly interpolates Y times between each succes...

2 years ago

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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) ...]...

2 years ago

Solved

We love vectorized solutions. Problem 1 : remove the row average.

Given a 2-d matrix, remove the row average from each row. Your solution MUST be vectorized. The solution will be tested for ac...

2 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...

2 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: ...

2 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...

2 years ago

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Remove the two elements next to NaN value

The aim is to *remove the two elements next to NaN values* inside a vector. For example: x = [6 10 5 8 9 NaN 23 9 7 3 21 ...

3 years ago

Solved

First non-zero element in each column

For a given matrix, calculate the index of the first non-zero element in each column. Assuming a column with all elements zero ...

3 years ago

Solved

Generate N equally spaced intervals between -L and L

Given N and L, return a list of numbers (in ascending order) that divides the interval [-L L] into N equal-length segments. F...

3 years ago

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Reindex a vector

You are given two vectors of equal length. Vector N has numeric values (no Inf or NaN) while vector IDX has integers. Place th...

3 years ago

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Specific Element Count

Given a vector _v_ and a element _e_, return the number of occurrences of _e_ in _v_. Note: NaNs are equal and there may be n...

3 years ago

Solved

Return unique values without sorting

If the input vector A is [42 1 1], the output value B must be the unique values [42 1] The *values of B are in the s...

3 years ago

Solved

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)).

3 years ago

Solved

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...

3 years ago