Polynomial2D example 5

This example shows the usage of [[Polynomial2D_]] class.

Modules and classes

• [[Polynomial2D_]]

Usage

PROGRAM main
use easifemBase
use easifemClasses
implicit none
type(Polynomial2D_) :: f1, f2
real(dfp), allocatable :: coeff( : )
integer(i4b), allocatable :: degree( :, : )

!!! note "Initiate" Initiate the object.

$$y=1+x+y+xy$$

  coeff = [1,1,1,1]
  call reallocate( degree, 4, 2 )
  degree(:,1) = [0,1,0,1]
  degree(:,2) = [0,0,1,1]
  call f1%initiate( coeff, degree, "x", "y" )
  call f1%display( 'f(x,y)=' )

!!! note "Grad"

$$\frac{df}{dx} = 1+y$$

    f2 = f1 .GRAD. 1
    call f2%display( "dfdx=" )

!!! example "result"

$$ans=+1x^0*y^0+1x^0*y^1$$

!!! note "Grad"

$$\frac{df}{dy} = 1+x$$

    f2 = f1 .GRAD. 2
    call f2%display( "dfdy=" )

!!! example "result"

$$dfdy=+1x^0*y^0+1x^1*y^0$$

END PROGRAM main