# Rafael Hernandez-Walls

My interest is everything related to numerical schemes applied to PDE and Oceanography, UABC.

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**Content Feed**

how i can find the chessboard lines and draw on the main image with any solution

Maybe you can use the Radon Transform, like this link: https://www.mathworks.com/help/images/detect-lines-using-the-radon-trans...

16 days ago | 0

how can I get y which correspond to x and then plot (x,y)??

Try this: x=linspace(-4,4); for r=1:length(x) y(r)=fzero(@(y)y.^3+0.2*exp(-1*x(r).^2)*y.^2-2.2039*y.^2+0.8155,1); end p...

1 month ago | 0

How to read data from text file and store as it is with variables

Assuming you have a file with only following line (name of file= 'algo.txt'): phi1_32_1 = 1 You could then read the line with...

1 month ago | 0

numerical simulation of travelling wave of epidemic model

try this.... clear all; xl=0; xr=1; %domain[xl,xr] J=1000; % J: number of dividion for x dx=(x...

2 months ago | 0

Read a txt file

try this Dens1 = [A(:,1),9.11*A(:,2).^(1.326)]; fileID1=fopen('E1.txt','w'); % [n,~]=size(Dens1); for k=1:n b=fprintf(...

3 months ago | 0

How to display correlation coefficents on plot?

you can try something like this: x = [0 0.000009 0.000018 0.000028 0.000037 0.000046 0.000055 0.000065 0.000074 0.000083 0.0000...

3 months ago | 0

extracting value from a matrix

I think it is better to put the variable X as a string and from there start. for example: X=['1000000000000000000000000000000...

3 months ago | 0

| accepted

How to get Taylor polynomial for functions?

You can use a function that is in the MAThWORKS fileexchange (I put the link): str=input('Function? ','s'); %tray with: cos(x)...

3 months ago | 0

| accepted

Change the sign of a Vector over N intervals

Use something like this: Y=rand(1,20); d=[1:4,8:12,17:20]; Y(d)=-Y(d)

4 months ago | 0

For loop only outputting the final value.

Try using something like this: t=linspace(0,3*pi,100) t=linspace(0,3*pi,100); for k=1:length(t) y = q2(t(k)); val...

4 months ago | 0

Plotting log x and y

Why don't you treat like this: n = 30; x = 0.5; h(1) = 1; emin = 1; for i =1:n if i==1 h(1)=0.5; else ...

5 months ago | 0

Solved

Calculate the answer to life the universe and everything

<https://en.wikipedia.org/wiki/42_(number)>

7 months ago

Solved

Simpsons's rule (but not Homer Simpson)

I wonder what Homer Simpson would have thought of Simpson's rule? Somehow I doubt his thoughts would have included the phrase Ne...

7 months ago

How can i draw the graph of this two functions using matlab

when i have this like problem i use this code: t=linspace(0,2*pi,50); f=((t>0)&(t<=1)).*2+((t>1)&(t<=pi/2)).*0.5.*t.^2+((t>pi...

7 months ago | 0