diffX

Differentiate a gridded field in the periodic x direction.

---

Declaration

 derivative = diffX(field,options)

Parameters

• field gridded field with the transform’s spatial shape
• options.n derivative order; default 1

Returns

• derivative x derivative with the same shape as field

Discussion

Differentiate a gridded field in the periodic x direction.

The derivative is evaluated spectrally. The input and output retain the same spatial layout, and derivative order n defaults to 1.

dudx = wvt.diffX(u);