Please i need to plot 3 dimension figure with (x axis is x, y axis is gamma function) and z axis is value of u for this simple attached relation

The constants mu=beta=g=1. The x is vector from -20 to 20.t=2. I need to plot three dimensions Xis vector x, y axis is values of gamma alfa and z is u.

Image added by @Sam Chak

Answer 1

[Sam Chak]

Hi @Tarek, @T K

For complex equations, I tend to use a symbolic approach because it allows me to verify their correctness. You should be able to write your equations accordingly. Please update your code and display the surface.

% declare symbolic variables
syms x y

% write the surface equation, z = f(x, y)
xi      = @(x, y) (x + 1/4./gamma(y + 1).*2.^y)/10;
z       = - 1/4*(1 + erf(sqrt(3)/2*xi(x, y)) - 1/2*exp(- sqrt(3)/2*xi(x, y).^2));

% display the equation
disp(z)

% plot the surface
fsurf(z, [-20, 20, 0, 10])
view(30, 30)
xlabel('x')
ylabel('y')
zlabel('z')

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Answer 2

[Torsten]

We don't know your problem, but it should work somehow like this.

What do you mean by "the y-axis is the gamma function" ? Do you want to graph z-values as a curve over the gamma-function in the x-y-plane ?

x = -20:20;
y = 3:0.25:5;
z = y.' .* x;
surf(x,y,z)

[Tarek]

@ Torsten.The simple relation is attached in above photo.I need to plot surf figure such that : X axis is vector for x -20 to 20: t is fixed value 2 : Y axis is vector for the gamma(alfa+1) where alfa changing from _3 to 3 : Z axis is u.

[Tarek]

The constants mu^2/(beta=gamma) =1and (mu/beta)=1

[Sam Chak]

Hi @Tarek

Since coefficients mu^2/(beta=gamma) =1 and (mu/beta)=1 are insignificant to you, could you follow up from here and type out the second equation for u? This will help ensure that your equations are expressed correctly.

Make sure that the equations are correct before plotting the the bivariate function.

%% Step 1: Declare symbols
syms alpha xi x t

%% Step 2: Type out Equation 1
eq1 = xi == (x + 6/(25*gamma(alpha + 1))*t^alpha)

eq1 = 

Although you defined the range for α from to 3, it is important to note that the Gamma function in MATLAB also accepts negative real and decimal numbers. Be careful!

gamma(-3)

ans = Inf

gamma(-1.2345)

ans = 4.1636

[Tarek]

@Sam: gamma function start from +1 to 10 . And the relation

[Star Strider]

@Tarek --

The image is not showing up for me.

This is what I get --

Plese use the 'Image (Ctrl+Alt+Z)' icon in the top toolbar (leftmost icon in the INSERT section).

.

[Sam Chak]

@Tarek, Could you verify on your end why the domain of Gamma function, starts from +1 to 10 when you defined the range for alpha, α is from -3 to 3? This is important to clarify!

By the way, since you replied using your mobile device, can you access MATLAB Mobile to code the equation? Additionally, all images you uploaded from your mobile device can only be viewed in mobile mode but not in desktop mode.

[T K]

[T K]

The domain of Gamma function starts from +1 to 10 because the (gamma zero) =infinity.The coefficient

(mu^2/(beta*ga)) =1, (mu/beta)=1and t=1.

X-axis is x starting from -20 to +20. Y -axis is is alfa starting from 0 to 10. Z-axis is u.

I need to plot surf(x,alfa,u)