# David Hill

Electrical Engineering with minors in Computer Science, Mathematics, and Creative Writing.

Working as Undergraduate Research Assistant in the field of Computational Photonics

**Statistics**

RANK**47**

of 239,506

REPUTATION**3,096**

CONTRIBUTIONS

**0** Questions

**1,304** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**327**

RANK**3,574** of 16,817

REPUTATION**368**

AVERAGE RATING**4.80**

CONTRIBUTIONS**18** Files

DOWNLOADS **123**

ALL TIME DOWNLOADS**2604**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

Multiply each element of a matrix by different element from another matrix

massg=10^-5:10; %mass [g] mass=massg/1000; %mass [kg] Ra_leo=2000; Ra_geo=35786; % altitude[km] R=6378; %Radius of Earth [km]...

4 days ago | 0

Solved

Method of Common Differences part-2

This is the inverse problem to <http://www.mathworks.com/matlabcentral/cody/problems/1485 Problem 1485>. Problem 1485 illustra...

5 days ago

Solved

Method of Common Differences part-1

Use the method of common differences to output a vector containing the initial values and the nth order difference. ex ...

5 days ago

Solved

Draw a x-by-x matrix 'Denmark flag'(Euro(2020)

Draw a x-by-x matrix 'Denmark flag' using '4' and '1'.(x is odd and bigger than 4) Number 4: Caption S.Kjær and number 1: K.S...

15 days ago

Solved

Draw matrix 'Swiss flag'( Euro 2020)

Draw a x-by-x matrix 'Swiss flag' using '1' and 0.(x is odd and bigger than 4) Example x=5 ans = [1 1 1 1 ...

15 days ago

Solved

Find numbers in the Popular Computing Z-sequence

Here’s a quick one. In 1977 the magazine Popular Computing sought “problem situations for which the computer is the best (if not...

15 days ago

Improving the speed of a double for loop through vectorization or changing summation indices

What is rep doing? Seems to just be multiplying. for rep = 1:10000 for p=0:N_M_min for q=0:p coeff(p+1) = coeff(...

16 days ago | 0

Solved

List Honaker primes

The number 131 is the 32nd prime number. It is a Honaker prime because the sum of its digits (1+3+1) equals the sum of the digit...

16 days ago

Solved

Hoax Numbers

A Hoax Number (OEIS A019506) is defined as a composite number, whose sum of digits is equal to the sum of digits of its distinct...

16 days ago

Solved

Palindromic Prime

Palindromic Prime is a prime number that is also a palindromic number. (Wiki, OEIS) If given a monotonic series (increment=1) ...

16 days ago

Solved

Bessel Polynomials

Return the n-th Bessel polynomial Assume that n is a non-negative finite integer. bessel_poly(0) ans = 1 bessel_poly(1) ...

16 days ago

Solved

Which Prime

Given two prime numbers, specify the relation between them i.e. - 'Twin Prime', 'Cousin Prime', 'Sexy Prime' or 'None'

16 days ago

Solved

Generate a matrix as follows

write a Function that gives like the following for a random n: n=2 ans= [ 0 1 1 0] n=6 ans= [ 0 ...

16 days ago

A simple rout algorithm in finding the way from point (0,0) to a random point (x1,y1) in a block

I would use a graph. M=zeros(100);%adjacency matrix start r=randperm(100,11);%ten random nodes with last node the end point e...

17 days ago | 1

| accepted

How to use multiple break statments

for i = 1:100 if ~(sln2.Error<=1) Ext.W22=beta*Ext.W22; Ext.W22List(i) = Ext.W22; end sln3.Erro...

18 days ago | 0

| accepted

Find minimum and maximum from same matrix

m=yourMatrix; m(m<=0)=inf; Min=min(m,[],'all'); m=yourMatrix; m(m>=0)=0; Max=-max(abs(m),[],'all');

18 days ago | 0

Find Consecutive numbers and print value in next collumn

Simple loop works c=0; f(:,6)=0; for k=1:size(f,1) if f(k,5)==1 c=c+1; f(k,6)=c; else c=0; end end

18 days ago | 1

Check every element of an array with if statement

z = [0.2+(-500:.05:500)*1i]; R = (z-1)./(z+1); x = abs(R); idx=x<=1; plot(real(R(idx)),imag(R(idx)),'b'); title('R Pla...

18 days ago | 0

| accepted

Producing all combinations of a vector with replacement

[x,y]=meshgrid(1:4); z=unique(sort([x(:),y(:)],2),'rows');

18 days ago | 1

| accepted

Solved

Back to basics 13 - Input variables

Covering some basic topics I haven't seen elsewhere on Cody. Return as a string the name of the input variable to the functio...

30 days ago

Solved

Back to basics 4 - Search Path

Covering some basic topics I haven't seen elsewhere on Cody. Return a string that is the user's portion of the current search...

30 days ago

Solved

N-Cards Problem

You have a deck of _N_ cards numbered in order from 1 to _N_. You discard the top card (card 1) and place the next card (card 2)...

30 days ago

Solved

Determine if a Given Number is a Triangle Number

*Description:* Determine if the elements of an input array are triangle numbers and return the result as an array with the sa...

30 days ago

Cicle for read data.

for k=0:95 T= sprintf("M3%d.dat",k); M3{k+1}= readtable(T, opts);%must start indexing at 1 end

1 month ago | 0

| accepted

How do I solve the double integral r dr d theta from 0,pi/2 and 0,4

syms r theta a=int(int(r,'theta',0,pi/2),'r',0,4);

1 month ago | 1

| accepted

Problems in for loop with cell array

Why not just use fit() function x=0:.01:2*pi; y=(5+.05*randn(size(x))).*sin((3+.05*randn(size(x))).*x); f=fit(x',y','sin1'); ...

1 month ago | 0

| accepted

How do I solve the triple integral xz^2siny from 0,pi/2,0,pi/2,1,2?

syms x y z; eqn=x*z^2*sin(y); a=int(int(int(eqn,'x',0,pi/2),'y',0,pi/2),'z',1,2);

1 month ago | 0

HOW CAN I PLOT THIS?

load('EXAMPLE.mat'); m=table2array(GIULIAMMEQ1); d=datenum(m(:,1)); v=str2double(m(:,2)); idx=~isnan(v); plot(d(idx),v(idx)...

1 month ago | 0

Solved

Compute the effective conductivity of a heterogeneous aquifer

Slow flow through soil or another porous medium follows Darcy’s law, which relates the flow of water to the gradient in piezome...

1 month ago

Solved

Pick the die most likely to win

After discussing Rock, Paper, Scissors, Lizard, Spock in The Simpsons and their Mathematical Secrets, Simon Singh writes that in...

1 month ago