# George Papazafeiropoulos

Major, Infrastructure Engineer, Hellenic Air Force Civil Engineer, M.Sc., Ph.D.

**Statistics**

RANK**579**

of 279,914

REPUTATION**116**

CONTRIBUTIONS

**0** Questions

**65** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**23**

RANK**397** of 18,775

REPUTATION**3,949**

AVERAGE RATING**4.40**

CONTRIBUTIONS**23** Files

DOWNLOADS **253**

ALL TIME DOWNLOADS**35738**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

Solved

make an eye matrix which element is 1:n

for a given input n, make an n by n matrix which contains elements 1:n for example input =5 output = [1 0 0 0 0;0 2 0 0 0; 0...

6 years ago

Solved

basics -making a matrix

make a matrix which contains input x as the last element. the intervals should be +1 ex) input = 5 output= [0 1 2 3 4 5] ex)...

6 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...

6 years ago

Solved

surrounded centroid

create a [n*n] matrix. n must be odd number. its centroid is n which is surrounded by n-1. example: surround(5)= 1 2 ...

6 years ago

Solved

create a square matrix

create a [n*n] matrix. example: mat(4)= [ 1 4 9 16 4 4 9 16 9 9 ...

6 years ago

Solved

Calculate the hypotenuse of a right triangle without using ^ and sqrt ()

Find out the hypotenuse of right triangle. Say a = 4, b = 3 then c = 5 Please don't use ^ and sqrt() function.

6 years ago

Solved

Solve sin(x) without sin(x)

Calculate y = sin(x) x = 0 -> y= 0 without the use of sin(x) or cos(x)

6 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...

6 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 ...

6 years ago

Solved

Times 2 - START HERE

Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

6 years ago

Solved

N-plicate me

Modified version of duplicate and triplicate me. Repeat elements of input vector with given input n Ex: input = [1 2 3 4 5...

6 years ago

Solved

tridiagonal matrix

Given vectors u and v, make a tri-diagonal symmetric matrix such that u is in the main diagonal and v is below and above diagona...

6 years ago

Solved

Calculate inverse matrix in m by n matrix

x=(1:10)' y=roundn(2*x+7*rand(size(x)),-1) a*x=y Estimate a using inverse matrix calculation. This is principle of li...

6 years ago

Solved

Sum positive elements of matrix.

Calculate sum of positive elements of the matrix.

6 years ago

Solved

Change matrix to vector

Vector is a matrix whose size is 1 x n or n x 1. Change matrix to vector. x = 4 3 5 1 ...

6 years ago

Solved

Two dimensional moving average

A=[1 2 3 4 5 1 2 2 2 3 2 3 3 3 4 1 1 4 4 2] B=[1 1;1 1]; % This is can be used for weight factor of moving a...

6 years ago

Solved

Triplicate me

Given an input vector, output a 3n vector with all elements of input vector repeated thrice Example : in->[1 2 3 5] out...

6 years ago

Solved

Implement zero-based indexing for Matrices

Given an input vector and position (which is zero based) output the value Example: x = [1 2; 4 5] pos = [0 1] value = 5 ...

6 years ago

Solved

Implement zero based indexing (Vectors only)

Given an input vector and position (which is zero based) output the value Example: x = [1 2 4 5] pos = 2 value = 4

6 years ago

Solved

Find the sum of all the numbers of the input vector

Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

6 years ago

Solved

Frequency Analysis of Text

Frequency analysis is a common task in cryptoanalysis. It is essentially counting the occurrences of alphabets (regardless of ca...

6 years ago

Solved

Reduce the logic

We have three logical input, x,y and z. The output is: y = ((x&y)|z)&((z|x&y)|(z&y|x))|((x&z)|z)&((y|x&z)|(z&x|y))|(x|y|z) ...

6 years ago

Solved

cross in array

Make a cross from "1" in odd size array. Other value from array should be equal to "0"; As input you get length of side of arra...

6 years ago

Solved

Geometrical meaning of determinant

Given two vectors x,y, in 2D or three vectors x,y,z in 3D space, compute the area (or volume) of the parallelogram they define. ...

6 years ago

Solved

Convert a vector to a lower triangular matrix

I now have a row vector and I want to convert it to a lower trilangular matrix. The rows of the lower trilangular matrix have...

6 years ago

Solved

Rotate array 90 degrees

Example, A = [1 2 3 ; 4 5 6 ] B = rotated(A) = [ 3 6; 2 5; 1 4 ]

6 years ago

Solved

Pad zero between every adjacent values of the vector.

you are given a vector x. you have to make an output vector y with zeros padded between every adjacent values of x. e.g x: ...

6 years ago