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# Alan Stevens

Last seen: Today Aktiv seit 2020

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Beantwortet
Function g Returns Only 2 Values Instead of Array - Vectorized Operation Issue in MATLAB
You have g as a function of x2, but x2 doesn't appear on the right-hand side!

ein Tag vor | 0

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Solve for x with given equation
Look up the help on function fzero. And don't forget that Matlab doesn't recognise implicit multiplication. x(...) should...

3 Tage vor | 0

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power method with rayleigh coeff
Make sure you call the function with the arguments in the same order as those defined in the function! A=[4 1 -1 0;1 3 -1 0;-1 ...

4 Tage vor | 0

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Beantwortet
Fill area between two vertical curves
Like this: value = [186.7646 198.4115 191.1406 180.8430 175.7136 ... 167.7459 151.2865 144.5964 139.8148 139.4305 188.2865 204...

23 Tage vor | 2

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Beantwortet
Simplificar el resultado como valor numerico
Why not simply: p1=[2;3] ; x0_1=@(theta) [cos(theta); sin(theta)]; % =[x1*x0; x1*y0] y0_1=@(theta)[-sin(theta); cos(theta)];...

27 Tage vor | 1

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Optimizing code for HAC Weight matrix generation - How to be faster?
Try replacing the loops with something like this: i = (1:size(Weight_correlation,1))'; j = 1:size(Weight_correlation,2); c = ...

30 Tage vor | 0

Beantwortet
How to a create a label at the bottom of a vertical line?
Like this? x = linspace(0,6,100); y = exp(x); plot(x,y) xline(4.5,'-',{'Acceptable','Limit'}, 'LabelVerticalAlignment', 'bot...

etwa ein Monat vor | 0

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Beantwortet
Secant method Nan Error
You haven't updated error in your while loop. Try including something like error = abs(X0-X1);

etwa ein Monat vor | 0

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Beantwortet
Function error in ODEs RK4 method, solving 6 unknowns
It works for me (I've commented out the fprint statements in the code below - but it works with them in!): global CDin psi thet...

etwa ein Monat vor | 0

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Beantwortet
I keep getting the error using '/'.
Try mu_ratio=(1-(vol_frac(c,1)/0.605).*((particle_ratio(c,1)).^1.2)).^(-1.5125); Notice the dots! .* .^ Difficult to be...

etwa ein Monat vor | 0

Beantwortet
Plateau followed by one phase decay
Like this? x = 0:0.5:20; % time in seconds Y0 = -0.6; % signal baseline value Plateau = -1; % singnal plateu after trigger/st...

etwa 2 Monate vor | 1

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Beantwortet
Radiation view factor using Monte Carlo
I think you probably need cos(theta), rather than theta, to be linearly spaced.

2 Monate vor | 0

Beantwortet
How to fix a syntax in the oscillator's plot code?
Like this (both x_1 and x_2 are contained in y) T0 = 10; omega0 = 1; M = 1; F = 1; x_1 = 0; x_2 = 0; x_0 = [x_1 x_2]; ts...

2 Monate vor | 0

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Beantwortet
ODE45has long runtime and graph will not plot
Here's my attempt to make sense of your equations tauspan = 0:100:10000; % p0 = [0.5 0.5 0 0]; % dp1dt = -rf + rr % dp2...

3 Monate vor | 0

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Two graphs in the same plot, why?
Something like this data = xlsread('sunHoursInTrollhattan.xlsx'); mins = data(:,1)*60 + data(:,2); plot(1:12, mins,'o'),grid ...

3 Monate vor | 0

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Beantwortet
Two graphs in the same plot, why?
You have the hours as one plot and the minutes as the other! Turn the data into all minutes, or all hours first.

3 Monate vor | 0

Beantwortet
Could anyone help me in fixing the problem in my code for solving the initial value problem numerically: y'=y^2, y(0)=1?
Here's an attempt using fminsearch. I don't know anything about the Obreschkoff method, so couldn't say if your equations are...

3 Monate vor | 0

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Beantwortet
I get this message(Attempted to access F(5); index out of bounds because numel(F)=4.) when I run the code below..
In fsode you try to use F(7) when calculating F(5), before you have calculated F(7)!

3 Monate vor | 1

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Beantwortet
Laser Rate Equation Modelling
Like this? (Look at lines 27, 28 and 38) %Script % Define model parameters temperature = 25; wavelength = 1.312e...

3 Monate vor | 0

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Determine the coordinates of the nodes forming the outermost circle
Here's an alternative way: nodes = importdata("nodes.mat"); figure plot3(nodes(:,1),nodes(:,2),nodes(:,3),'b.','Markersize',1...

3 Monate vor | 0

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Problem with fitting a loglog plot
polyfit doesn't like the log of zero. One option is to remove the first row of the data: data_exp_high = load("data_Q_1e-8.txt...

3 Monate vor | 0

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Index in position 2 exceeds array bounds (Index must not exceed 1) errors?
N0 is a 4x1 vector, but you call it with two indices in the for loop! Turn N(1,j) into N(1) and similarly for the other calls t...

3 Monate vor | 0

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Beantwortet
How do I solve this ODE system where there exists derivatives in both sides?
You can separate the terms as follows:

3 Monate vor | 0

Beantwortet
why am i getting grey figure box can someone fix please
Making some assumptions about your function pendulumODE, I think the following is more like what you expect to see: % Constants...

3 Monate vor | 0

Beantwortet
Algae growing, concentration curve problem
Increase nt to 10000 and it works just fine for T = 20000.

3 Monate vor | 0

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Error ''Array indices must be positive integers or logical values.'' when putting interval of 0.01 in a for loop
More like this: k = 0:0.1:2; n = numel(k); for i = 1:n x(i) = k(i); y(i) = k(i)*k(i) + 3*k(i) - 4; end plot(x,y...

4 Monate vor | 0

Beantwortet
Trying to code from Polymath
Like this for example (I'll leave you to extract the numerical values): Wspan = [0 2]; % Integration range % Initial valu...

4 Monate vor | 0

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Unable to solve differential equation with finite difference method
Should be more like this I think: b = 0.02; m = 80; L = 0.7; g = 9.81; J = m * L^2/3; a = 0; bet = 2; alpha = 0; beta = 3...

4 Monate vor | 0

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FDM using succsesive overrelaxation method,
For w1 and T1 you have w1(:,Nx1+1) = (((la*B1*dx1)/(dx2*A1))*(w2(:,2)-w2(:,1)))+w1(:,Nx1); %Continuity of shear stress ...

4 Monate vor | 0

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Solving first order ODE with initial conditions and symbolic function
You can do it numerically as follows: % input parameters Tinf=70+273.15; Ti=20+273.15; d=15e-2; r=d/2; cdepth=10/1100; Tf...

5 Monate vor | 0