difforms - Maple Programming Help

Home : Support : Online Help : Mathematics : Differential Equations : Differential Forms : difforms/mixpar

difforms

 mixpar
 ensure equality of mixed partial derivatives

 Calling Sequence mixpar(expr)

Parameters

 expr - Maple expression

Description

 • The function mixpar will take nested calls to diff, and sort the sequence of differentiations so that they are sorted by lexicographical ordering on the variables of differentiation.
 • The purpose of this function is to ensure that equal mixed partials are recognized as equal.
 • The command with(difforms,mixpar) allows the use of the abbreviated form of this command.

Examples

 > $\mathrm{with}\left(\mathrm{difforms}\right):$$\mathrm{defform}\left(f=0,x=0,y=0,z=0\right)$
 > $d\left(f\left(x,y,z\right)\right)$
 $\left(\frac{{\partial }}{{\partial }{x}}{}{f}{}\left({x}{,}{y}{,}{z}\right)\right){}{d}{}\left({x}\right){+}\left(\frac{{\partial }}{{\partial }{y}}{}{f}{}\left({x}{,}{y}{,}{z}\right)\right){}{d}{}\left({y}\right){+}\left(\frac{{\partial }}{{\partial }{z}}{}{f}{}\left({x}{,}{y}{,}{z}\right)\right){}{d}{}\left({z}\right)$ (1)
 > $d\left(\right)$
 ${0}$ (2)
 > $\mathrm{mixpar}\left(\right)$
 ${\mathrm{mixpar}}{}\left({0}\right)$ (3)