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# dulanga

Last seen: 2 years ago Active since 2014

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poisson need help with this
he Poisson Equation on the square domain 0<x<1, 0<y<1, with u=g(x,y) on the boundary, where Finish this code, with node ...

3 years ago | 0 answers | 0

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Question

i need help with this question
I am supposed to find the number of timesteps i.e the number of steps taken but my answer is incorrect any inputs on my code wil...

3 years ago | 0 answers | 0

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Question

plotting help needed (increasing resolution)
this is my code how would i increase the resolution of the graph? N = 101; tmin = 0; tmax = 3; t = linspace(tmin,tmax,N...

3 years ago | 1 answer | 0

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i need to get the maximum amplitude in this code but my final answer is wrong
The data file https://www.dropbox.com/s/8b8u38ghve7tfv0/Data.mat?dl=0 i get 28400 as the answer but the answer is wrong plus t...

3 years ago | 1 answer | 1

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Question

I get this error what should i do to correct this? Index exceeds matrix dimensions. Error in t31 (line 11) F1=Fmag((N/2)+1:N)...

3 years ago | 0 answers | 0

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Question

need help with the question
This code is not working i am using this to calulate the amplitude but i am getting this error Index exceeds matrix dimensi...

3 years ago | 1 answer | 0

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Question

need help with this
turn all the amplitudes of frequencies which are higher than 3500 Hz into 0’s and amplify the rest of the spectrum (by just mul...

3 years ago | 1 answer | 0

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Initial value problem need help with

3 years ago | 0 answers | 0

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Question

need help with problem
what is wrong in this code i dont get the correct answer xleft=0; xright=(9*pi)/4; N=20; x=linspace(xleft,xright,N); x=x...

3 years ago | 2 answers | 0

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Question

heun mthod 1st order ode
Is this code correct and how do i find which integer time t is the solution y(t) closest to -0.2 y0 = -1; % In...

3 years ago | 1 answer | 0

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euler method first order
thanks for your comments John the multiplication when it was supposed to be an addition was a mistake on my part.

3 years ago | 0

Question

euler method first order
This is my code is this correct? y0 = -1; % Initial Condition h = 0.1; t = 0:h:100; N=lengt...

3 years ago | 2 answers | 0

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Question

Lu decomposition help needed
this is as far as i have got can anyone help me? function [L,U] = LUdecomp(A) n = size(A,1); %number of rows m = size(A,2...

3 years ago | 0 answers | 0

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residual r=ax-b ∞-norm
Would this be correct to get infinty norm a = [-5 8 -5; 0 0 12; 3 -7 -3;6 -4 4] b = [1;1;1;1] x=a\b r=a*x-b N = norm(r, I...

3 years ago | 0

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Question

residual r=ax-b ∞-norm
This is my code but i dont get the coorect answer a = [-5 8 -5; 0 0 12; 3 -7 -3;6 -4 4] b = [1;1;1;1] x=a\b r=a*x-b x1=sq...

3 years ago | 2 answers | 0

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Question

product series in matlab
Error when taking zero. clc clear syms k P1 = symprod((k-(4/k))-5 , k, 0, 3) P2 = symprod((k-(4/k))-5 , k, 6, 100)

3 years ago | 0 answers | 0

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summation using syms and rounding
is this way correct?Also want the number rounded to the first dp. syms k f = k-4/k-5; v1 = subs(f, k, 1:3) s_sum = sum(v...

3 years ago | 0 answers | 0

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Question

plotting ellipsoid any help
how can i plot this out ? 4x^2 + y^2 + 9z^2 = 36 thanks

5 years ago | 0 answers | 0

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Question

the question asks to subplot the contours any idea how?
x = linspace (-1,1); y = linspace (-1,1); [X, Y] = meshgrid(x,y); Z=7*sin(pi.*X).*cos(3*pi.*X); surf(X,Y,Z ) hold on con...

5 years ago | 1 answer | 0

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Question

i get error saying that z should be a matrix and not a scalar
x = linspace (-1,1); y = linspace (-1,1); [X, Y] = meshgrid(x,y); Z=7*sin(pi.*x).*cos(3*pi.*x); surf(X,Y,Z ) hold on con...

5 years ago | 1 answer | 0