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Rafael Hernandez-Walls


Last seen: Today
1.139 total contributions since 2010

My interest is everything related to numerical schemes applied to PDE and Oceanography, UABC.

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Solved


MinMax mapping
Given a matrix, map all the elements within a given interval. For example, a=[ 2 5 10] mapped in the interval [1,2] ...

ongeveer 7 uur ago

Solved


Rescale Scores
Each column (except last) of matrix |X| contains students' scores in a course assignment or a test. The last column has a weight...

ongeveer 7 uur ago

Solved


Find the Best Hotels
Given three input variables: * |hotels| - a list of hotel names * |ratings| - their ratings in a city * |cutoff| - the rat...

ongeveer 8 uur ago

Solved


Crop an Image
A grayscale image is represented as a matrix in MATLAB. Each matrix element represents a pixel in the image. An element value re...

ongeveer 8 uur ago

Solved


Calculate a Damped Sinusoid
The equation of a damped sinusoid can be written as |y = A.ⅇ^(-λt)*cos(2πft)| where |A|, |λ|, and |f| ...

ongeveer 8 uur ago

Solved


Verify Law of Large Numbers
If a large number of fair N-sided dice are rolled, the average of the simulated rolls is likely to be close to the mean of 1,2,....

ongeveer 8 uur ago

Solved


Calculate BMI
Given a matrix |hw| (height and weight) with two columns, calculate BMI using these formulas: * 1 kilogram = 2.2 pounds * 1 ...

ongeveer 8 uur ago

Solved


Find the average of a random sequance
Write a function that generates random integers within a loop, and calculates the mean of the positive numbers only. At each ...

3 dagen ago

Solved


Horizontal matrix sort
Given a matrix x with n rows and m columns, return a matrix y with n rows and 2m columns, such that every row in x is sorted fro...

3 dagen ago

Solved


Find the index of nth maximum of a row vector of real numbers
Given a vector of real numbers x, find the index idx of _n_ th maximum value. If nth maximum occurs more than once, return the i...

3 dagen ago

Solved


Please check if calorie intake is less than 300 kcal.
I like eating some puddings and some chocolate cookies around 3 o'clock. However, I care about calorie intake. Please check whe...

3 dagen ago

Solved


means
Calculate the arithmetic, the geometric and the harmonic mean of a given vector (with positive elements) and return them in a ve...

3 dagen ago

Solved


Energy-Mass Equivalence
Given input enegy of the object, E, and constant c = 300,000,000, find the mass of the object.

3 dagen ago

Solved


Repetition of matrices
*A is a bold matrix: [1 2 3; 4 5 6;7 8 9]* Given an integer 'n' , a matrix B exists such that has n copies of A in the row an...

17 dagen ago

Solved


Plot Damped Sinusoid
Given two vectors |t| and |y|, make a plot containing a blue ( |b| ) dashed ( |--| ) line of |y| versus |t|. Mark the minimum...

25 dagen ago

Solved


frame of the matrix
Given the matrix M, return M without the external frame.

25 dagen ago

Solved


Calculate Amount of Cake Frosting
Given two input variables |r| and |h|, which stand for the radius and height of a cake, calculate the surface area of the cake y...

27 dagen ago

Solved


How long does it take to run a bath?
Given the *volume flow rate* (volume/time) of a faucet and the *volume* of a bath tub, find the amount of time it takes to fill ...

ongeveer een maand ago

Solved


R2012b atan in Degrees
Return in degrees the atan result of inputs for all four quadrants. *Examples:* [x, y] Degrees 1 0 0 1 1 ...

ongeveer een maand ago

Answered
finding all indices of a value in matrix
A=[2 2 3 ; 2 4 2; 2 3 2]; [r,c]=find(A==min(A))

ongeveer een maand ago | 0

| accepted

Solved


Remove duplicated triangles
Input T is a triangulation (triplet list of indices -positive integers-, each index refering to a vertex number in a correspondi...

4 maanden ago

Solved


Weighted moving average
x1=[1 2 1]; y1=[1 2 2 4 5 6 6 8]; Make function for weighted moving average. z(i)=(x1(i)*y1(i)+x1(i+1)*y1(i+1)+x1(i+2)*y1...

4 maanden ago

Solved


Height of a right-angled triangle
Given numbers a, b and c, find the height of the right angled triangle with sides a and b and hypotenuse c, for the base c. If a...

4 maanden ago

Solved


Separate even from odd numbers in a vector - with a loop
*Using a loop*, rearrange a vector of integers such that the odd numbers appear at the beginning, and even numbers at the end. T...

4 maanden ago

Solved


Angle of triangle
For three unknown points a b c, given three sides ab bc ca, find three angles abc bca cab in radians. Your function should b...

4 maanden ago

Solved


Find the Oldest Person in a Room
Given two input vectors: * |name| - user last names * |age| - corresponding age of the person Return the name of the ol...

4 maanden ago

Solved


Compute Fibonacci Number
Compute the _n_-th Fibonacci Number f(0) = 0, f(1) = 1, f(2) = 1, f(3) = 2, ... f(42) = 267914296

4 maanden ago

Solved


Given a 4x4 matrix, swap the two middle columns
If a = [1 2 3 4; 1 2 3 4; 1 2 3 4; 1 2 3 4]; then the result is ans = 1 3 2 4 1 3 2...

4 maanden ago

Solved


Can we make a triangle?
Given three positive number, check whether a triangle can be made with these sides length or not. remember that in a triangle su...

4 maanden ago

Solved


Divisible by 10
Pursuant to the <http://www.mathworks.com/matlabcentral/cody/problems/42404-divisible-by-2 first problem> in this series, this o...

4 maanden ago

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