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Alan Stevens


Last seen: Today
886 total contributions since 2020

Alan Stevens's Badges

  • 12 Month Streak
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  • Knowledgeable Level 4
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Answered
how can i solve this problem with rk4 method?
If m=20, k=20, c=40 then function f should be f = -(c/m)*v - k/m f=@(t,x,v) -2*v -x; %dvdt

14 hours ago | 0

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Answered
How to solve a function with different ranges
Try C_ox = [16;15;7.5;2;7.5;15;15]; C_ox(C_ox<=15)=C_ox(C_ox<=15)/15; C_ox(C_ox>15)=1

1 day ago | 0

Answered
how can i solve second order ODE with RK-4 without using a built in function in matlab?
This K11 = RK4(t(i), y1(:, i)); should be | K11 = RK4(t(i), y(:, i)); and this f12 = -3*y(1)+30*t+10; ...

2 days ago | 0

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Answered
How to design the membership function in matlab?
How about the following for rule 3 (I'll leave you to invert for rule 4). x = [-180 -90 -89.001 89.001 90 180]; y = (x+180)/90...

5 days ago | 0

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Answered
Help for plotting graph. Can someone help me?
In your while loop you don't update either nErrorsBitsW or nErrorsBitsInf so they always stay at 0, and never reach minNbits.

6 days ago | 0

Answered
how I can insert these specific colours into my figures
Do you mean something like this? newcolors = [0 0.4470 0.7410; 0.8500 0.3250 0.0980; 0.9290 0.6940 0.1250...

7 days ago | 1

Answered
Transpose x from a row vector to a column vector using the transpose operator. The program is prompting the x does not have correct values. the code i have entered is below
You probably meant x = [1:5]; % ie the ; is after the ] However, it seems to work ok for me as you wrote it!

7 days ago | 0

Answered
Replace a entry of a table of Bisection Method for a specific term
Try using NaN or [ ];

8 days ago | 0

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Answered
Plotting the intersection of a composition function
Do you mean something like this? Sfn = @(x) (x+1/4).*(x<=1/2) + (x+3/4).*(x>1/2); x = linspace(0,1,100); n=10; S = zeros(n,n...

18 days ago | 0

Answered
Sun Synchronous with For Loop
When I run the program you've listed above it produces the graph you show!

18 days ago | 0

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Answered
Integration of a function with variable parameter
Do you mean something like this? H = @(tau, lam, tt) lam./exp(tt-tau); T=50; step=1000; h=T/step; t=0:h:T; lambda = rand(1...

19 days ago | 0

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Answered
How to get sinusodial behaviour from 2nd order ode using function handle?
You coud try implementing the function along these lines (obviously, you will need to use your own values for alpha etc): alpha...

20 days ago | 0

Answered
How to find absolute maximum value of (x*(x-.25)*(x-.5)*(x-1))
You could just do something like gx = @(x) ((x.^4) -(1.75*x.^3)+(0.875*x.^2)-(0.125*x)); X = roots([4, -5.25, 1.75, -0.125]); ...

21 days ago | 0

Answered
I want to see N,M first and then K,M in the same legend. I can see only N,M like the attached picture.
Do you mean like this? N = [10 20 30 40 50]; M = [1 2 3 4 5]; K=[1 3 5 6 7]; x = linspace(0, 1, 17); legendString = "N = " ...

21 days ago | 0

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Answered
How to take integral with for loop?
Add the command I = sum(final); after the loop.

23 days ago | 0

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Answered
Solving queue problem iterating through array
Try Lock19(Lock19~=-5)=0; Lock19(Lock19==-5)=3;

23 days ago | 0

Answered
Sum of even numbers
Like so s = test(6); disp(s) function s = test(n) if n <= 0 %for n<= 0 the result would be 0 s = 0; els...

29 days ago | 0

Answered
Stopping ode45 when encountering errors and retrieving results
The following makes your example work. However, I suspect your real problem is more complicated. If so, you should upload it. ...

29 days ago | 0

Answered
After comma precision tracking for if statement
Here's one possibility a=85.0093792283283; b=85.0093791964294; a = floor(a*10^3); b = floor(b*10^3); if a==b disp('n...

29 days ago | 0

Answered
help me solve this if statement
Remove the ] in the top line! Then number = randi([0,9]) evens = [2,4,6,8]; odds = [1,3,5,7,9]; if ismember(number,evens) ...

29 days ago | 0

Answered
𝑦 = 2𝑐𝑜𝑠3𝑥
help plot

1 month ago | 0

Answered
Error: ode45 Must return a column vector?
Like this? % the total time domain response % System parameters k3 = 15; k1 = 10.0; k2 = 10.0; m1 = 2.0; m2 = 6.0; L = 1.0;...

1 month ago | 1

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Answered
How to solve following BVP ODE?
Weird ODE and initial boundary condition! You can solve for small values of x using the following (where y(x=0) was chosen by t...

1 month ago | 1

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Answered
Array indexes must be positive integers or logical values.
Looks like you are using SUM when you want sum. Change to: SUM= E1*sum(V(3:IOUT+1,JOUT+2)).... Also, in line 59, you should h...

1 month ago | 1

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Answered
How to get real solutions of a "system of nonlinear equations"?
If you are willing to do the differentiation by hand then the following works % L = 2*x^2 -2*x*y+y^3 + lambda*(x^2 + y^2 -4); ...

1 month ago | 0

Answered
Calling Euler Method to solve Shooting Method
You need to express your 2nd order ode as two 1st order odes y``(x) + 5y`(x) + 4y(x) = 1 v = dy/dx dv/dx = y``(x) So you h...

1 month ago | 0

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Answered
solving Diffrential equation one parameter related to another one
Like this? %% Input Parameters Rs = 200; Rr = 180; Phi = 180; t = 0:1:359; e = Rs - Rr; %% Calculation B = @(t) e*co...

1 month ago | 0

Answered
error handling for complex equation
nchoosek(pc-1+iL,pc-1-k) Your value of pc-1-k isn't a non-negative integer, but it needs to be for nchoosk. Also why use s...

1 month ago | 0

Answered
merging two ode graphs
Your testode2 function must return a column vector. Try function dy = testode2(~,y) %%% Must return a column vector j=1;bet...

1 month ago | 0

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Answered
Simulation of differential equations with multiple variables. Biotechnology
You set umax to be 0.33, but then treat it as a function in the definition of f. If umax should simply be multiplied by the oth...

1 month ago | 0

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