# Alan Stevens

Last seen: 2 days ago Active since 2020

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Answered
How to integrate an implicit acceleration function to a fitting pair of graphs of velocity and displacement
Look up ode45 for the integration (for a fixed set of parameters) and fminsearch for fitting the parameters to known data.

6 days ago | 0

Answered
Brush: How can I change the font color of the displayed X and Y range?
Select the Property Inspector, select the text, choose a color. (The following code is just to get the image uploaded) I=imrea...

18 days ago | 0

Answered
how to use an integral function inside a for loop? i need to find the value of function that chages as i chages .then using this values i need to find another integral.
Are you looking for something like this? r0 =0.1; u =[1:7]'; Q =zeros(length(u),1); E =zeros(length(Q),1); Q = @(x)0.023*(r...

18 days ago | 0

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Simpson integral - problem with writing the formula
Should be x(i) etc. not a(i). Also be careful with brackets. % Test 1 a = 0; b = 1; n = 10; f = @(x)1-x+x.^3; I = simpson(f...

24 days ago | 0

Answered
How do I apply iteration method to an integral?
Look up help on function fzero.

2 months ago | 1

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How can I plot a reflection angle of a projectile in a kinematics model? Overlay projectile motion plots?
Surely you only need to reverse the x-velocity? imperialBallVelocity = 52.20; release_angle = 42; release_height = 64.2; %Ki...

2 months ago | 0

Answered
Why am I receiving this error?
You have 4 layers layer_angles = [45, -45, -45, 45]; but data for only three mid_plane_strains = [0.05, 0.00, 0.00]; % Mid-p...

2 months ago | 0

Answered
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!

2 months ago | 0

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Answered
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...

2 months ago | 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 ...

2 months ago | 0

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Answered
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...

3 months ago | 2

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Answered
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)];...

3 months ago | 1

Answered
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 = ...

3 months ago | 0

Answered
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...

3 months ago | 0

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

3 months ago | 0

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Answered
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...

4 months ago | 0

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Answered
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...

4 months ago | 0

Answered
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...

4 months ago | 1

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

4 months ago | 0

Answered
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...

4 months ago | 0

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Answered
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...

5 months ago | 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 ...

5 months ago | 0

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Answered
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.

5 months ago | 0

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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...

5 months ago | 0

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Answered
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)!

5 months ago | 1

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

5 months ago | 0

Answered
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...

5 months ago | 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...

5 months ago | 0

Answered
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...

5 months ago | 0

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

6 months ago | 0