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# Alan Stevens

Last seen: Today Active since 2020

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Why does integration of an exponential function generate noisy results as opposed to its analytical solution?
You have a singularity when t = x(ii). Here's a rough and ready way to do the numerical integral (hmm! not sure the result is c...

4 days ago | 0

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Index exceeds the number of array elements. Index must not exceed 1
What are yoy trying to do with x_iEm(i) - h*x_iEm(i) == x_past + h*2*y; when i = 2, there is, as yet, no value assigned to x_...

5 days ago | 1

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Inconsistent results from "int" function
You can express '(y*(2*x + y)^2)/192 as (x*y*(x + y))/48+y^3/198 As far as the integral is concerned y is a constant, so the t...

7 days ago | 2

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Boole's Approximation
You are using Boole from -1 to 1, but the "exact" from 0 to pi. (You should plot G against x to see why your "exact" integral w...

9 days ago | 1

I'm trying to solve a system of differential equations using Euler's method, but I don't know what the problem is with my code. If you can correct me the problem
Don't confuse the number 1 with lower case l a= 0; b= 2; delta_x =0.5; y1(1) = 4; y2(1) = 6; n= (b-a)/delta_x + 1 ; x(1)...

9 days ago | 0

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How to add one sgtitle per row of suplots
Try subplot(2,3,1) scatter(62,VWE3a_diff,50,'MarkerEdgeColor','[0 0 0]','MarkerFaceColor','[0 0.5 1]','Marker','o') title('DM...

13 days ago | 0

How to add one sgtitle per row of suplots
Here's a quick and dirty way: x = 0:0.01:2*pi; for i=1:6 y = sin(x+i*pi/4); subplot(2,3,i) plot(x,y) ...

14 days ago | 1

How do you solve a System of 11 Non-Linear Equations Inter-linked to one another?
Here's a possible logic (though I seem to find negative values for U): U1 = 500; U2 = 500; % Initial guesses U0 = [U1 U2]; ...

16 days ago | 0

Title in maths symbol and title as legend on each plot on different locations.
More like this? %% Set up the data (just enough to need a large legend and to show variety) t = linspace(0, 1, 11); x = linsp...

17 days ago | 0

How to show Kinetic energy,potential energy at given ditance
Do you mean something like this: Tf=20; theta=60; height=5000; angle = 45; g=9.81; velocity=(g*Tf)/(2*sind(theta)); figur...

18 days ago | 0

Summation for every value of "n" (or summation with looping)
Like so: B=7.5; % angle value fn = @(n) (1+2*cos(n*B)).^5/2; n=1:50; Qn = fn(n); Q = sum(Qn); Pr= 395; P1= Pr/Q; disp(P1...

19 days ago | 1

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Implementing while loop in Heun's Method
Here's a rough and ready way (I'll leave you to implement Heun's method): f = @(H) -0.06*sqrt(H); H = 4; t = 0; dt = 0.1; %...

21 days ago | 2

How to explain a difference in solutions of integrals between MATLAB and MAPLE?
This is what I get in Maple:

24 days ago | 0

I want to put arrows on each of the lines parallel to x-axis using LOOP
Like this? p = 0.02:.07:1; plot([0; 1],[p; p], 'color','b'); hold on %q = 0.2:.2:1; xx = [0.5 0.57]; ...

25 days ago | 0

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How can I plot this signal?
Like this? gm = 0.04; RL = 10000; CL = 10^(-9); f = logspace(-1,2); Av = (-gm*RL)./(1 + RL*CL*f*1i); %magnitude subplot...

1 month ago | 0

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Hey so I am trying to code an ellipse and I was confused about the placement of my plot. Should it be before the for loop or after?
Something like this? (I've commented out your meshgrid commands as they just confuse the plot and I'm not at all clear why they ...

1 month ago | 1

Using Euler's Method for projectile motion
A little more like this? (I've used arbitrary values for initial conditions etc.) N = 200; % points to be taken g = 9.8; % acc...

1 month ago | 0

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need plot a graph using Euler's method for both numerical and analytical
f = a + (2 - 0.4*a) * x(i) / r^2 * pi; % x(i) not just x. % Also take note of the other comments above.

1 month ago | 1

How can I create a loop to show a table with number of iterations and its roots in secant method?
Possibly like this (though using a while loop would be better): f=@(x) exp(0.5*x)+(5*x); x(1)=0.8; x(2)=0.7; tol=0.0001; ...

2 months ago | 0

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Condition for output result

2 months ago | 0

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Why is my loop not ending?
Shouldn't dp(i+1)= ((6*m(i+1))/(pi*row))^(1/3); be dp(i+1)= -((6*m(i+1))/(pi*row))^(1/3); i.e. have a negative sign in front...

2 months ago | 0

Explicit solution can not be found using dsolve of second order differential equation
Do you have a reason to believe there is an analytical solution to this? It is simply solved numerically, as follows: X0 = [1,...

3 months ago | 0

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i am trying to add a legend for the 0.2% offset line onto the graph, but when i run this, the previous three legend just disappear.
Just put '0.2 offset line' as a fourth item in your other legend command.

3 months ago | 0

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Minimizing an equation to 0
Try fminsearch

3 months ago | 0

Solving for two variable.
In that case one way is to take logs of both sides to get: log(I) = log(I0) + q/(n*k*T)*U then do a best-fit straight line...

3 months ago | 0

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I couldn't plot the function because it seems vector length isn't same, please help me in it.
Try changing n = 100 for i = 1:n to n = numel(time); for i = 1:n-1

3 months ago | 0

How to plot an array graph from a 'for' loop?
Try multiplying i by delta_t in the plot command x(1) = 1; delta_t = 0.1; n = 100; for i = 1:n hold on grid ...

3 months ago | 1

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