I am now trying to define a CoefficientFunction using other library named Radia.

but the NGSolve says

```
TypeError: float() argument must be a string or a real number, not 'ngsolve.fem.CoefficientFunction'
```

Are there any alternatice ways to define such a CoefficientFunction?

```
import radia as rad
def H(x,y,z):
c1 = rad.ObjRaceTrk([0,0,0],[0.7,0.8],[0,0],0.1,12,10,"auto")
Hx = rad.Fld(c1,"bx",[x,y,z])
Hy = rad.Fld(c1,"by",[x,y,z])
Hz = rad.Fld(c1,"bz",[x,y,z])
return (Hx,Hy,Hz)
Hs = CoefficientFunction(H(x,y,z))
```