subroutine PLANK I ( DNU1, DNU2, TEMP, DELNU, C PI , O B ) !----------------------------------------------------------------- implicit real*8 ( a-h,o-z ) !----------------------------------------------------------------- NBND = INT ( ( DNU2 - DNU1 ) / DELNU ) B = 0.0D0 do INB = 1, NBND WNU = DNU1 + ( INB - 0.5 ) * DELNU B = B + DELNU * PI * ( 1.1911D-8 * WNU**3 ) / \ ( EXP( 1.439D0 * WNU / TEMP ) - 1.0D0 ) end do !----------------------------------------------------------------- return end