Community Profile

# Alan Stevens

Last seen: Today Attivo dal 2020

#### Content Feed

Visto da

Risposto
incorrect number or types of inputs or outputs for function 'int'
Replace your power calculation with power = (1/T_0) * trapz(t,y.^2); Edited - Walter is correct.

2 giorni fa | 0

Risposto
Regula-falsi Method that keeps running
Brackets!! f = @(x) 2.^x - x.^2 - 2; % Function whose roots are desired xL = 4; xU = 5; % Initial guesses Tol = 1...

12 giorni fa | 0

| accettato

Risposto
Trying to answer a math problem using newton's method but having problem in the function.
Matlab doesn't like implied multiplication (x ^ 2)z should be (x ^ 2)*z etc. Also, in Matlab log(x) is ln(x)

14 giorni fa | 0

| accettato

Risposto
How to set multiple values of a threshold?
Here's one way: tolX1_4 = [1 1 1 1 1 -1 1 1 0 1 1 1 1 1 1 1 1 ...

14 giorni fa | 0

| accettato

Risposto
Here's a numerical approach: First manipulate the equations tspan = [0, 120]; ic = [80000, 0.001]; [t, xy] = ode45(@rate, ...

16 giorni fa | 0

Risposto
how ode solver works
doc ode45 Go to the References section. The two references listed will supply you with all you need to know about the ode solv...

17 giorni fa | 0

Risposto
Solve Differential Equation with initial conditions and function
Try modifying your if statement in Moment. Something like if x<a V =...; M = ...; elseif x>=a && x<L M = ... ...

17 giorni fa | 0

Risposto
problem in creating function file using ode45
Are you looking for something like this? (I might have misinterpreted your equations!) O=1; a=pi/2; g=9.81; L=100; tspan ...

21 giorni fa | 0

Risposto
how can eliminate negative data in erf function?
Should term2(i) = (sqrt(lemdaD)./(2.*e1(i))).*exp(-(v1(i).*sqrt_avgsnr - v2(i).* mu).^2./(2.*e1(i).^2)).*.... erf((e4(...

21 giorni fa | 0

| accettato

Risposto
Why is my plot not showing for improved Euler method?
You need to keep track of each step. Your original simply overwrites the values of t and y at each step. dy=@(t,y) -(0.1/10^(1...

25 giorni fa | 1

Risposto
Why I couldn't plot this graph f=(@(x,y) (x.^2)+(x*y)+(y.^2)<=68200.^2/3);
This will give you the outline (I've assumed you want 68200^(2/3) rather than 68200^2/3) f=@(x,y) x.^2+x.*y+y.^2-68200.^(2/3); ...

27 giorni fa | 0

Risposto
I want to solve a simple "y=mx+c" with initial condition to find value of "m" and "c" but i am getting error by using following code. Any idea to tackle this kind of problem?
These are simple linear equations in m and c so set: X = [x(1) 1; x(2) 1]; Y = [y(1); y(2)]; and solve using X\Y to get m a...

28 giorni fa | 0

Risposto
I have been trying to code a solar pv module for 1 diode model, the following is my code, can someone tell me the mistake ive made and the correction to it pls.
Like this? Note: I've made kref positive to avoid the I's being complex. This might be completely incorrect!! Pmpp = 50; ...

28 giorni fa | 1

| accettato

Risposto
Reorganization of data in matrix
Like this? M = [1 1 0.270588872500870 1 1 0.191034400222846 1 1 0.316821350897659 1 1 0.391794699189989 1 2...

circa un mese fa | 0

Risposto
LogLog Plot is Blank
Like this? (I've assumed you want log base 10 everywhere): %Paschen Curve Plotting for H2 p = 1.2; %Torr d = 20; %cm GamSE ...

circa un mese fa | 1

Risposto
How to combine multiple numbers into 1 number?
Do you mean R1 = 2; R2 = 4; Zr1 = [0 0 0]; R = R1*10^4+R2*10^3+Zr1(1)*10^2+Zr1(2)*10+Zr1(3) Alternatively: R1 = 2; R2 = 4; Z...

circa un mese fa | 0

Risposto
Runge Kutta Fourth order and Interpolation
Shouldn't f1 = @(z,r,ed,p11,m11) -(ed+p11)*z*m11.^3 *((r+1)./(((ed+p11)*(r.^2 +z.^2).^6) -(r/p11))) ./(2*pi*(r.^2 + z.^2)) ; ...

circa un mese fa | 0

Risposto
Newton Raphson method for a system of non-linear equations?
Here's a simple example for you to follow: % Functions f = @(x,y) x^2 + y - 5.94; % i.e. the equation is x^2+y=5.94 g = @(x,...

circa 2 mesi fa | 0

| accettato

Risposto
No feasible solution in optimisation in linprog
I don't know if this will fix your problem, but I think the first number in the second row of A1 should be 8 not 2.

circa 2 mesi fa | 0

Risposto
Simple relaxation method Matlab
For the simple relaxation technique to work the A matrix needs to be diagonally dominant. Your A is not diagonally dominant - s...

circa 2 mesi fa | 0

| accettato

Risposto
Solve a system of 3 second order equations
Write your equations as 6 first order equations like so: where I've assumed you have pre-defined omegaout and thetaout as fun...

circa 2 mesi fa | 0

Risposto
Unable to solve nonlinear equation using fsolve as the message shows No solution found
fminsearch makes a reasonable attempt: F1 = @(a,b) -9.135789053E+00-log(a)+166.2509975*a+5.84074229*b+... -166.2509975*a^2...

circa 2 mesi fa | 2

Risposto
How to solve and plot this set of differential equations?
If rho starts at 0, then drho/dtheta will be zero and rho will not change from zero according to your first ode. If rho and drh...

circa 2 mesi fa | 0

Risposto
How can I add two differential equations to the system in a given time interval?
Like this? (though I'm not sure I've interpreted which constants apply during which interval correctly!) Tspan = 0:30; C0 =...

circa 2 mesi fa | 1

| accettato

Risposto
How do I plot Rosette-like diagram in this case?
Something like this? data=[10 10 30 100; 20 50 70 150; 30 45 60 120]; theta0 = deg2rad(data(:,2)); thetaf = deg2r...

circa 2 mesi fa | 1

| accettato

Risposto
Iteration of multiple nonlinear functions
Here's a quick and dirty way. I'll leave you to modify the following to record all the temperatures at every step. %Given valu...

2 mesi fa | 0

Risposto
converting table values to RPM
B{:,7}./(2*pi)*60

2 mesi fa | 0

| accettato

Risposto
using num2str for subplot titles
Try title(['Q1S', num2str(k)]) i.e. enclose the two terms within square brackets.

2 mesi fa | 0

| accettato

Risposto
control and simulation of petroleum distillation column
The following works, but probably doesn't contain all the right data or equations! % CALCULATE MATERIAL BALANCES FOR THE DISTIL...

2 mesi fa | 0

| accettato

Risposto
Error with plot command
You haven't specified function atten_func_dist, so we can't run your code to test it. You specify fre as a constant, then us...

2 mesi fa | 2

| accettato