Alan Stevens
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Contribute at least one answer each month for 12 consecutive months
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Content Feed
Removing zeros from matrix
Like this? A = [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 0; 1 2 3 4 0 0; 1 2 3 0 0 0]; B = A'; B=B(:); B(B==0)=[]
15 hours ago | 0
Error in ODE arguments
I suspect you mean like this (notice the way M divides, using the back-slash): % Numerical solution of IVP % M*xddot + C*x...
15 hours ago | 1
How to Approximate The Solution for an Initial Value Problem?
Try f = @(t,x) [x(2); sin(1.9*t)-4*x(1)]; [t,x] = ode45(f,[0,150],[1,0]); plot(t,x)
3 days ago | 1
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Creating a set range for a function
(x < 3) && (x > 25) An individual element of x can't be both less than 3 and greater than 25 at the same time. If here are ma...
4 days ago | 0
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Plotting the tangent line for newton raphson method
Like this? fx = @(x) x.^2 -2; dfdx = @(x) 2*x; n_step = 7 ; % Anzahl der durchzuführenden Schritte für Newtonverfahren...
5 days ago | 0
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Fit scatter plot with a curve
More like ths? x = [0.2337;0.296;0.3071;0.4208;0.2055;0.9597;0.8683;0.243;0.3363;0.2793;0.5292;0.2471;0.2282;0.4774;1.0392;0.43...
6 days ago | 1
Generating random numbers with a different probabilities
Assuming there are just two levels of probability, and that the numbers are real, not just integers, you could try: p50 = 0.75;...
7 days ago | 1
Hi, what does ; exactly mean?
It means start a new row, e.g. x = [1 2; 3 4]; disp(x)
9 days ago | 0
Solve the IVP y′′′=sin(y2)+y′+cos(t), provided with an appropriate set of initial conditions of your choice, and using Matlab's ODE45 function.
Like this? (Note the IC for d^2y/dt^2 must be consistent with the values chosen for y(0) and dy(0)/dt). Change the IC's and tim...
18 days ago | 0
Need Help Solving System of ODEs
You haven't included the first term on the right-hand side of your equation for dV/dt, nor for dgamma/dt.
20 days ago | 1
spring mass using ode45
Like this x0 = [0; 0]; tspan = [0, 10]; [t, x] = ode45(@func, tspan, x0); subplot(2,1,1) plot(t, x(:, 1)); grid('on...
20 days ago | 0
I am getting error in this program. Please suggest the corrections.
Change c = [1 2 2 3 4 5 6 7]; to c = [1 2 3 4 5 6 7];
20 days ago | 1
Hello, I'm trying to plot one non-piecewise function and two piecewise functions in one graph but I keep getting an error. I don't understand the two error messages below.
You need to put the non-local functions at the end, as in the following. There were several other errors. I don't know if my co...
21 days ago | 0
How to Solve equation using Eulers method in Matlab?
Here's part (a) for you - definitely not a straight line!
24 days ago | 0
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I need to set up a Runge Kutta solver for water leaving a bucket through a certain diameter nozzle as function of time, it says array indices must be positive integers/log val
Indices in Matlab start at 1, not 0, so you need for i=1:60:200 not for i=0:60:200
26 days ago | 0
How to get one output for each input into an equation in MATLAB?
mu = mu_max * (x./(x+Ks)); % Notice it is ./ not just /
29 days ago | 0
How to solve 'Index number exceeds number of array elements(1)'
You don't update XSOL, so when ct is 2, XSOL(ct) doesn't exist.
29 days ago | 0
A question about FitzHugh-Nagumo model
Like this? tspan = [0 100]; v0 = 0; w0 = 0; IC = [v0 w0]; A=0.5; B=0.05; Epsilon=0.005; I=@(t)sin(t); %%%%%%%%%%%%%%...
29 days ago | 0
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How to find parameters that minimize a difference
Use fminsearch and use the norm of the differences. help fminsearch
30 days ago | 2
I want to combine 2 variables in matlab into one variable
If they are imported as, say, c1 and c2, then you can simply write c = [c1; c2]; then delete the c1 and c2 if you don't need t...
1 month ago | 0
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How can i call an equation and it's derivative inside a matlab function?
Like this, perhaps: % TC is given in terms of percentage! x0=0; TC=10^-4; error=TC+1; i=0; x(1)=x0; while(error>TC) [f...
1 month ago | 0
simple Fixed Point Iteration
Probably more like this (though you don't seem to have used function f anywhere): n = 11; x = zeros(1,numel(n)); ea = zeros(1...
1 month ago | 0
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I want Estimate log to the base 10 value using 'x' number such that 10^estimated value is equal to or just exceeding x.
< not <= a = log10_bywhile( 50, 0.1 ) b = log10_bywhile( 100, 1 ) function [out] = log10_bywhile(x, inc) esmt = 0; % if...
1 month ago | 0
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How can I change the value of Y in the columns whare the value of X is zero in matrix ?
Like this XY = [1 5 0 10 3 26 0 5]; XY(XY(:,1)==0,2) = 1.5
1 month ago | 1
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multiple equations multiple variables solve command does not work
These equations are linear in the unknowns, so can be solved as follows: % M*X = V where X = [b; d; e] % and the coefficien...
1 month ago | 1
Is there an error in the if else statement?
Yes, among others! See: L1 = 16.87; %cm L2 = 60.35; L3 = 16.81; L4 = 63.06; L5 = 42.62; L7 = 19.64; theta_1 = 105.47; %de...
1 month ago | 1
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Solving ODE Boundary Value Problem by Finite Difference Method
I think you just need to change b(i+1) = (w*xi(L-xi))/(2*E*I); to b(i+1) = (w*xi*(L-xi))/(2*E*I); ...
1 month ago | 1
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Computing the double integral of a surface
Like this syms x y z = @(x,y) x.^2 + y.^2; surface_int = integral2(z,1,2,4,9); disp(surface_int)
1 month ago | 0
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Mod Euler Method with two ODEs
Like this %Mod_Euler_method Modified Euler's method % [t, w, h] = euler_method(f, a, b, alpha, n) performs Modified Euler's me...
1 month ago | 0
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