# Plotting a 3D finition with 1D implicite variable

1 view (last 30 days)
Thomas TJOCK-MBAGA on 18 Jul 2022
Edited: Torsten on 18 Jul 2022
Hello! I have a 3D advection-dispersion équation as follows: dC/dt = Dx *d^2C/dx^2 + Dy *d^2C/dy^2 + Dz *d^2C/dz^2 - vx *dC/dx - vy *dC/dy - vy *dC/dz -mu*C. When using change of variable e.g. X = a*x + b*y + c*z i obtained a 1D advection-dispersion équation: dC/dt = D *d^2C/dX^2 - V*dC/dX -mu*C. The solution si in the form C(X,t) = exp((V/2D)*X+√V^2 + 4*D*mu)*erfc((X+√ 4*D*mu)/2√D*t).My problème si that i wanted to plot thé concentration C with respect to x, y, ans z for fixes values of other variables. How Can i do or in MATLAB knowing that the solution si expressed in term of X???
KSSV on 18 Jul 2022
DEfine your variables, write the formula; substitude the variables in the formula and plot.
Torsten on 18 Jul 2022
Edited: Torsten on 18 Jul 2022
I have a 3D advection-dispersion équation as follows: dC/dt = Dx *d^2C/dx^2 + Dy *d^2C/dy^2 + Dz *d^2C/dz^2 - vx *dC/dx - vy *dC/dy - vy *dC/dz -mu*C. When using change of variable e.g. X = a*x + b*y + c*z i obtained a 1D advection-dispersion équation: dC/dt = D *d^2C/dX^2 - V*dC/dX -mu*C.
Many people would be very happy if this worked, but such a magic transformation does not exist. Unfortunately.

### Categories

Find more on Startup and Shutdown in Help Center and File Exchange

R2018b

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!