Community Profile

# Matthias Witkowski

##### Last seen: 9ヶ月 前
54 2017 年以降の合計貢献数

#### Matthias Witkowski's バッジ

removal of frequency from 0-200HZ
It is not recommendable to zero fft bins as this corresponds to a convolution with a sinc function in time domain, this will int...

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...

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...

Decode a simplified barcode
Given a bar code from this <http://www.mathworks.com/matlabcentral/cody/problems/602-make-a-simplified-bar-code exercise>: Re...

Convert Roman to Arabic Numerals
Based upon what I see on tv and at the movies, the use of Roman numerals indicates something is important or sophisticated (e.g....

Converting numbers back from extended form
Thanks for all the help you guys gave me on writing out the numbers in extended form in <http://www.mathworks.com/matlabcentral/...

Reverse Calculator
Use this reverse calculator and give correct output Its simple, In my Reverse calculator if you press 0 it will be considered...

Ripping numbers apart!
So you have to "rip" a number apart into individual digits... The end output is a cell. That is if: x = 12345678 o...

Rounding off numbers to n decimals
Inspired by a mistake in one of the problems I created, I created this problem where you have to round off a floating point numb...

Make a simplified barcode
Given an integer to encode, make a barcode using the following encoding scheme: * The bar code is made from the binary versio...

Sort a list of complex numbers based on far they are from the origin.
Given a list of complex numbers z, return a list zSorted such that the numbers that are farthest from the origin (0+0i) appear f...

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...

Increment a number, given its digits
Take as input an array of digits (e.g. x = [1 2 3]) and output an array of digits that is that number "incremented" properly, (i...

Number of 1s in the Binary Representation of a Number
*Description* Return the number of 1s in the (unsigned integer) binary representation of a number. This function should be ab...

Reverse the elements of an array
Reverse the order of elements in an array: eg: input X = [ 1 2 3 ; 4 5 6 ; 7 8 9 ] o...

Minefield Sonar
*Background* In mine-hunting games (e.g. Microsoft Minesweeper), the user is provided with a covered grid that, upon a left c...

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 [...

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 ...

Create logical matrix with a specific row and column sums
Given two numbers *|n|* and *|s|*, build an |n-by-n| logical matrix (of only zeros and ones), such that both the row sums and th...

Put two time series onto the same time basis
Use interpolation to align two time series onto the same time vector. This is a problem that comes up in <http://www.mathwork...

Joining Ranges
You are given a n-by-2 matrix. Each row represents a numeric range, e.g. x = [0 5; 10 3; 20 15; 16 19; 25 25] contains...

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...

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...

intersection of matrices
Given two matrices filled with ones and zeros, determine if they share a common row, column entry. These matrices are of identi...

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...

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 ...

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

Return a list sorted by number of consecutive occurrences
Inspired by Problem 38 by Cody Team. Given a vector x, return a vector y of the values in x sorted by the number of CONSECUTIVE...

Longest run of consecutive numbers
Given a vector a, find the number(s) that is/are repeated consecutively most often. For example, if you have a = [1 2 2 2 1 ...

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...