Rafael Hernandez-Walls

Last seen: 7 días ago

1.319 total contributions since 2010

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

Rafael Hernandez-Walls's Badges

Answered
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...

7 días ago | 0

Answered
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...

14 días ago | 0

Answered
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...

alrededor de 1 mes ago | 0

Answered
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(...

alrededor de 2 meses ago | 0

Answered
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...

alrededor de 2 meses ago | 0

Answered
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...

2 meses ago | 0

| accepted

Answered
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)...

2 meses ago | 0

| accepted

Answered
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)

3 meses ago | 0

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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...

3 meses ago | 0

Answered
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 ...

4 meses ago | 0

Solved

Mass Conversion 2

6 meses ago

Solved

Calculate the answer to life the universe and everything
<https://en.wikipedia.org/wiki/42_(number)>

6 meses ago

Solved

How many hours are there in a day in Italy?
Remember "European Summer Time"

6 meses ago

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Temperature Conversion 3

6 meses ago

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Temperature Conversion 2

6 meses ago

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Temperature Conversion 1

6 meses 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...

6 meses ago

Solved

Total energy

6 meses ago

Solved

Potential energy calculation

6 meses ago

Solved

Kinetic energy calculation

6 meses ago

Solved

Laws of motion 7

6 meses ago

Solved

Laws of motion 6

6 meses ago

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Laws of motion 5

6 meses ago

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Laws of motion 4

6 meses ago

Solved

Laws of motion 3

6 meses ago

Solved

Laws of motion 2

6 meses ago

Solved

Laws of motion 1

6 meses ago

Answered
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...

6 meses ago | 0

Answered
Finding the length of square function
t2=t(find(diff(X)>0)); t1=t(find(diff(X)<0)); long_time=t2(2)-t1(2)

7 meses ago | 0

Answered
How to create a sine wave with variable frequency - Simulink
something like this: (?) t=linspace(0,2*pi,100); f=rand(1,100); y=sin(f.*t); plot(t,y)

7 meses ago | 0