Community Profile

# Wolfgang Schwanghart

### University of Postdam

160 total contributions since 2007

Professional Interests: GIS, Physical Geography, Hydrology, Geomorphology

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Question

Fit Gaussian mixture model with weighted observations
Hi everyone, looking at the help of fitgmdist, I cannot see that there is the possibility to weight observations. Is there a rea...

18 days ago | 2 answers | 0

### 2

2D gaussian filter with a variable sigma
Hi Chad, below is some code that does the trick using nlfilter. To be more efficient, I created a look-up table with a finite s...

8 months ago | 0

Submitted

TopoToolbox
A MATLAB program for the analysis of digital elevation models

1 year ago | 45 downloads |

What makes a Toolbox a Toolbox, and how is it recognized by Matlab?
Hi Chad, the trick is to have a Contents.m-file in the main folder of your toolbox. In TopoToolbox, the file starts with T...

1 year ago | 0

Submitted

Non-crossing polynomial quantile regression
Non-crossing polynomial quantile regression

4 years ago | 4 downloads |

Submitted

Flow Accumulation (upslope area)
Flow accumulation algorithm that routes through flats

5 years ago | 7 downloads |

Solved

Box!
Given a box, find the volume of the cube. With each side = a.

5 years ago

Question

Customized icons in workspace
Hi all, I have written a couple of MATLAB classes and, as icing on the cake, I'd like to have customized icons in the worksp...

6 years ago | 0 answers | 1

### 0

Solved

index of n in magic(n)
let input=5; magic matrix 17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 ...

6 years ago

Solved

Order of things - 1
Let's assume you have a number of calculations to perform, that depend on each other. E.g. 'A' can be calculated, once the outco...

6 years ago

Solved

Count decimal digits of a number
* Given an integer number you have to return the number of its digits. * For example 248 has 3 digits and 1589 has 4 digits ...

6 years ago

Solved

Check if equal
Return true if all the elements of an nD array are equal, false otherwise.

6 years ago

Solved

Add a row of zeros on top of a matrix
Given a matrix, insert a row of zeros as the top row.

6 years ago

Solved

Too Many Zeros, Dump Them!
Sometimes when I create a matrix, I use this syntax: a = zeros(1000,1000); But when the function ends, I find that I don'...

6 years ago

Solved

Enlarge array
Given an mxn numeric array (A) and a 1x2 vector (sz) indicating the dimensions [p q] to enlarge each element, return an (m*p)x(n...

6 years ago

Solved

Pascal's pyramid
In Pascal's triangle each number is the sum of the two nearest numbers in the line above: 1 1 1 ...

6 years ago

Solved

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 [...

6 years ago

Solved

Matrix to column conversion
Given a matrix of any size, convert it into a column vector. e.g A=[10 20 30; 40 50 60] then, B = [10; 40; ...

6 years ago

Solved

Find the index of the largest value in any vector X=[4,3,4,5,9,12,0,4.....5]
The given function returns the index of the maximum value in a given matrix. such as X=[4,3,4,5,9,12,0,5] Ans= 6 if maxim...

6 years ago

Solved

Free passes for everyone!
_Simply return the name of the coolest numerical computation software ever_ *Extra reward* (get a _freepass_): As an addit...

6 years ago

Solved

Number of digits in an integer
Specifies how many digits in a given integer. Example: in=100 ==> out=3

6 years ago

Solved

Generate a NaN...on purpose
The goal is to create a function that will return a single "NaN" without using the nan function. I am interested to see how many...

6 years ago

Solved

Finding peaks
Find the peak values in the signal. The peak value is defined as the local maxima. For example, x= [1 12 3 2 7 0 3 1 19 7]; ...

6 years ago

Solved

Find smallest integer type to accommodate your number
MATLAB supports 1-, 2-, 4-, and 8-byte storage for integer data. Find the smallest integer type to accomodate a scalar integer. ...

7 years ago

Problem

Find smallest integer type to accommodate your number
MATLAB supports 1-, 2-, 4-, and 8-byte storage for integer data. Find the smallest integer type to accomodate a scalar integer. ...

7 years ago | 0

Solved

Max index of 3D array
Given a three dimensional array M(m,n,p) write a code that finds the three coordinates x,y,z of the Maximum value. Example ...

7 years ago

Solved

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...

7 years ago

Solved

Create matrix of replicated elements
Given an input element x, and the dimensions, (m, n) return a matrix of size m x n filled with element x. Example: Input: ...

7 years ago

Solved

It's race time again! Write a function that is at least twice as fast as the test suite call of repmat().
Given an input element x, and the dimensions, (m, n) return a matrix of size m x n filled with element x. This must be done in l...

7 years ago

Solved

Convert elements in numeric array into different class
Write a function that converts elements in a numeric array into a different class. Example: a = [1:5]; % class: double b...

7 years ago