Repeat

  {  REPEAT.PDE  }

{

   This problem illustrates the use of the REPEAT statement to generate

   repetitive structures, and the string facility for labelling such

   domains.

}

title 'REPEAT and $string test'

Variables

    u

definitions

    a = 1

    xc=array(1/3, 2/3, 3/3, 4/3, 5/3)  { a list of X-coordinates }

    yc=array(1/3, 2/3, 3/3, 4/3, 5/3)  { a list of Y-coordinates }

   rad = 0.1

   s = 0

equations

    div(a*grad(u)) + s  = 0;           { the heatflow equation }

boundaries

    region 1

       start(0,0)

       value(u)=0        line to (2,0) to (2,2) to (0,2) to close

    region 2

        a = 0.05

        s = 4*magnitude(x-1,y-1)

       repeat i=1 to 5                    { an indexed loop on X-position }

           repeat j=1 to 5                { an indexed loop on Y-position }

               { an array of circular dots at the tabulated coordinates }

               start  'loop'+intstring(i)+intstring(j) (xc[i]+rad,yc[j])

               arc(center=xc[i],yc[j]) angle=360

           endrepeat

       endrepeat

monitors

    contour(u)

plots

    contour(u) painted

       repeat i=1 to 5

           repeat j=1 to 5

               elevation(u) on  'loop'+$i+$(j)

           endrepeat

       endrepeat

end