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{ TABULATE.PDE

 

 This problem tabulates an arithmetic expression into a data table.

 

 The structure of the inline tabulate command is:

   TABULATE <range_controls> : <expression>

 

 The <range_control> clause is

   VERSUS  <name> ( <list_specification> )

 or

   FOR  <name> ( <list_specification> )

 

 A <list_specification> may be the name of an array or a list of values,

 possibly including "BY <step> TO <last>" clauses.

 

 A TABULATE command can be preceded by SPLINE to request

 spline interpolation rather than the default linear interpolation.

 

TABLES may be constructed with one, two or three coordinates.

 

 The constructed tables are exported in various forms, to show the use

 of TABULATE to create tables for other FlexPDE applications to use.

 

}

title 'Tabulation Test'

select

 regrid=off

 

variables

 u

definitions

 alpha =tabulate versus x(0 by 0.1 to 10)

                versus y(0 by 0.1 to 10)

                 : sin(x)*sin(y)+1.1

 xar =array (0 by 0.1 to 10)

 beta =spline tabulate for x(xar)

                      for y(0 by 0.1 to 10)

                       : sin(x)*sin(y)+1.1

 p = x

 q = p+y

 s = y^2*(p+q)

equations

 U:   div(beta*grad(u)) + alpha = 0

boundaries

region 1

  start(0,10)

  value(u) = 0

  line to (0,0) to (10,0) to (10,10) to close

monitors

contour(u)

plots

grid(x,y) as "computation mesh"

contour(u) as "solution"

surface(u) as "solution"

contour(alpha) as "tabulated data" export file='alpha.tbl'

contour(beta) as "spline-tabulated data"  

contour(alpha-beta) as "linear-spline difference"

vector(grad(alpha)) as "table gradient"

vector(grad(beta)) as "spline gradient"

surface(alpha) as "tabulated data"

surface(beta) as "spline data"

table(alpha)  

table(s)

vtk(beta)

contour(space_error())

end