Rodrigo Portugal

Active since 2012

Followers: 0 Following: 0

Message

Professional Interests: Seismic data processing, Appliead Mathematics, Scientific Computing, Numerical Methods

Statistics

All

RANK
11,589
of 159,122

CONTRIBUTIONS
0 Problems
44 Solutions

SCORE
460

NUMBER OF BADGES
2

View badges

Feeds

Solved

Replace NaNs with the number that appears to its left in the row.
Replace NaNs with the number that appears to its left in the row. If there are more than one consecutive NaNs, they should all ...

12 years ago

Solved

Binary numbers
Given a positive, scalar integer n, create a (2^n)-by-n double-precision matrix containing the binary numbers from 0 through 2^n...

12 years ago

Solved

Is my wife right? Now with even more wrong husband
Again, as in "Is my wife right?" ( <http://www.mathworks.com/matlabcentral/cody/problems/149-is-my-wife-right> ), answer 'yes' r...

12 years ago

Solved

Return the largest number that is adjacent to a zero
This example comes from Steve Eddins' blog: <http://blogs.mathworks.com/steve/2009/05/27/learning-lessons-from-a-one-liner/ Lear...

12 years ago

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...

12 years ago

Solved

Nearest Numbers
Given a row vector of numbers, find the indices of the two nearest numbers. Examples: [index1 index2] = nearestNumbers([2 5 3...

12 years ago

Solved

Too mean-spirited
Find the mean of each consecutive pair of numbers in the input row vector. For example, x=[1 2 3] ----> y = [1.5 2.5] x=[1...

12 years ago

Solved

The Hitchhiker's Guide to MATLAB
Output logical "true" if the input is the answer to life, the universe and everything. Otherwise, output logical "false".

12 years ago

Solved

Target sorting
Sort the given list of numbers |a| according to how far away each element is from the target value |t|. The result should return...

12 years ago

Solved

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]

12 years ago

Solved

Distance walked 1D
Suppose you go from position 7 to 10 to 6 to 4. Then you have walked 9 units of distance, since 7 to 10 is 3 units, 10 to 6 is 4...

12 years ago

Solved

The Goldbach Conjecture
The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

12 years ago

Solved

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...

12 years ago

Solved

Summing digits
Given n, find the sum of the digits that make up 2^n. Example: Input n = 7 Output b = 11 since 2^7 = 128, and 1 + ...

12 years ago

Solved

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.

12 years ago

Solved

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...

12 years ago

Solved

Remove any row in which a NaN appears
Given the matrix A, return B in which all the rows that have one or more <http://www.mathworks.com/help/techdoc/ref/nan.html NaN...

12 years ago

Solved

Create times-tables
At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 times 12 is way more th...

12 years ago

Solved

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...

12 years ago

Solved

Pizza!
Given a circular pizza with radius _z_ and thickness _a_, return the pizza's volume. [ _z_ is first input argument.] Non-scor...

12 years ago

Solved

Weighted average
Given two lists of numbers, determine the weighted average. Example [1 2 3] and [10 15 20] should result in 33.333...

12 years ago

Solved

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

12 years ago

Solved

Fibonacci sequence
Calculate the nth Fibonacci number. Given n, return f where f = fib(n) and f(1) = 1, f(2) = 1, f(3) = 2, ... Examples: Inpu...

12 years ago

Solved

Swap the first and last columns
Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

12 years ago

Solved

Make a checkerboard matrix
Given an integer n, make an n-by-n matrix made up of alternating ones and zeros as shown below. The a(1,1) should be 1. Example...

12 years ago

Solved

Triangle Numbers
Triangle numbers are the sums of successive integers. So 6 is a triangle number because 6 = 1 + 2 + 3 which can be displa...

12 years ago

Solved

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 ...

12 years ago

Solved

Making change
Given an amount of currency, return a vector of this form: [100 50 20 10 5 2 1 0.5 0.25 0.1 0.05 0.01] Example: Input a = ...

12 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...

12 years ago

Solved

Add two numbers
Given a and b, return the sum a+b in c.

12 years ago