Dear Users!

Hoped everyone fine here. I have three main questions regarding the maple code given bellow:

restart; with(LinearAlgebra); with(plots);

alpha := 1; beta := 1; theta := 1/2;

UU := sinh(x)*sinh(y)*sinh(z)*exp(-1.*t);

NN := 3; L := 0; R := 1; T := 1; N := NN; Mx := NN; My := NN; Mz := NN; `Δx` := (R-L)/Mx; `Δy` := (R-L)/My; `Δz` := (R-L)/Mz; `Δt` := (R-L)/N;

kappa[1] := 1; kappa[2] := 2/x^2; kappa[3] := 1/x^2; kappa[X] := x^2+y^2+z^2+1; kappa[Y] := x^2+y^2+z^2+1; kappa[Z] := x^2+y^2+z^2+1; kappa[4] := 0; NL := 3;

ics := [seq(seq(seq([u[i, j, k, 0] = eval(UU, [x = i*`Δx`, y = j*`Δy`, z = k*`Δz`, t = 0]), u[i, j, k, -1] = eval(u[i, j, k, 1]-2*`Δt`*(eval(diff(UU, t), t = 0)), [x = i*`Δx`, y = j*`Δy`, z = k*`Δz`, t = 0])][], i = 0 .. Mx), j = 0 .. My), k = 0 .. Mz)];

bcs := [seq(seq(seq([u[0, j, k, n] = eval(UU, [x = 0, y = j*`Δy`, z = k*`Δz`, t = n*`Δt`]), u[Mx, j, k, n] = eval(UU, [x = L, y = j*`Δy`, z = k*`Δz`, t = n*`Δt`])][], j = 0 .. My), k = 0 .. Mz), n = 1 .. N), seq(seq(seq([u[i, 0, k, n] = eval(UU, [x = i*`Δx`, y = 0, z = k*`Δz`, t = n*`Δt`]), u[i, My, k, n] = eval(UU, [x = i*`Δx`, y = L, z = k*`Δz`, t = n*`Δt`])][], i = 1 .. Mx-1), k = 0 .. Mz), n = 1 .. N), seq(seq(seq([u[i, j, 0, n] = eval(UU, [x = i*`Δx`, y = j*`Δy`, z = 0, t = n*`Δt`]), u[i, j, Mz, n] = eval(UU, [x = i*`Δx`, y = j*`Δy`, z = L, t = n*`Δt`])][], i = 1 .. Mx-1), j = 1 .. My-1), n = 1 .. N)];

Sol := {u[1, 1, 1, 1] = 0.2366497936e-1, u[1, 1, 1, 2] = 0.7589975856e-2, u[1, 1, 1, 3] = 0.6029906475e-3, u[1, 1, 2, 1] = 0.3778786317e-1, u[1, 1, 2, 2] = 0.7126415819e-2, u[1, 1, 2, 3] = -0.1197885714e-2, u[1, 2, 1, 1] = 0.3778786315e-1, u[1, 2, 1, 2] = 0.7126415820e-2, u[1, 2, 1, 3] = -0.1197885718e-2, u[1, 2, 2, 1] = 0.6038763054e-1, u[1, 2, 2, 2] = 0.4264591907e-2, u[1, 2, 2, 3] = -0.3509477851e-2, u[2, 1, 1, 1] = 0.3171958616e-1, u[2, 1, 1, 2] = -0.1327161715e-1, u[2, 1, 1, 3] = -0.4628647419e-2, u[2, 1, 2, 1] = 0.4979852397e-1, u[2, 1, 2, 2] = -0.3060811899e-1, u[2, 1, 2, 3] = -0.344914876e-4, u[2, 2, 1, 1] = 0.4979852397e-1, u[2, 2, 1, 2] = -0.3060811898e-1, u[2, 2, 1, 3] = -0.3449150010e-4, u[2, 2, 2, 1] = 0.7882396741e-1, u[2, 2, 2, 2] = -0.6192340018e-1, u[2, 2, 2, 3] = 0.1156615222e-1}

Using set of points given in **ics**, **bcs** and **Sol**

1. I want to contruct a vector at any time level (by fixing fourth suffix like u[i,j,k,**n**]) for i = 0..Mx,j=0..My,k=0..Mz and then find its L2 and L[infinity] norms.

2. Next I want contruct a vector by fixing two suffixes like u[i,j,**k,n**]) for i = 0..Mx,j=0..My and plot a surface in 3D

3. Finally I want to construct a vector by fixing three suffixes like u[i,**j,k,n**]) for i = 0..Mx, and plot a curve in 2D.

I'm waiting for your positive respone. I shall be very thankfull to you in advance.

Special request to:

@acer @Carl Love @Kitonum @Preben Alsholm