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# Alan Stevens

Last seen: Today Active since 2020

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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!

ongeveer 20 uur ago | 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 dagen ago | 0

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 dagen ago | 0

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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 dagen ago | 2

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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 dagen ago | 1

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 = ...

29 dagen ago | 0

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...

ongeveer een maand ago | 0

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

ongeveer een maand ago | 0

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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...

ongeveer een maand ago | 0

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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...

ongeveer een maand ago | 0

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...

ongeveer 2 maanden ago | 1

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

2 maanden ago | 0

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 maanden ago | 0

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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...

2 maanden ago | 0

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 maanden ago | 0

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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 maanden ago | 0

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 maanden ago | 0

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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 maanden ago | 1

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

3 maanden ago | 0

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 maanden ago | 0

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 maanden ago | 0

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 maanden ago | 0

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

3 maanden ago | 0

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 maanden ago | 0

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

3 maanden ago | 0

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 maanden ago | 0

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 maanden ago | 0

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 maanden ago | 0