1 #======================================================================

     2 #                    . I S O P L E T H . S I G M A 0 

     3 #                    doc: Tue Dec 13 21:50:18 2005

     4 #                    dlm: Wed Dec 14 09:40:50 2005

     5 #                    (c) 2005 A.M. Thurnherr

     6 #                    uE-Info: 44 43 NIL 0 0 72 2 2 4 NIL ofnI

     7 #======================================================================

     8 

     9 # HISTORY:

    10 #	Dec 14, 2005: - created

    11 

    12 # NOTES:

    13 #	- assumes T/S fields to be called 'temp' and 'salin'

    14 

    15 require "$ANTS/libEOS83.pl";				# load equation of state

    16 

    17 unless (defined($P{ITS})) {

    18 	&antsInfo("using default %ITS=90");

    19 	&antsAddParams(ITS,90);

    20 }

    21 

    22 sub yfield_isopleth($)						# return y-field based on x-field

    23 {

    24 	my($xf) = @_;

    25 	return $xf eq 'salin' ? 'temp' : 'salin';

    26 }

    27 

    28 sub bracket_isopleth($$$$)					# heuristically bracket y field

    29 {

    30 	my($xf,$xv,$iv,$prev_y) = @_;

    31 

    32 	if ($xf eq 'salin') {

    33 		return (-10,30);

    34 	} else {

    35 		return (34,37);

    36 	}

    37 }

    38 

    39 sub eval_isopleth($$$)						# evaluate function for isopleth

    40 {

    41 	my($xf,$x,$y) = @_;

    42 

    43 	return $xf eq 'salin' ? sigma($x,$y,0,0)

    44 						  : sigma($y,$x,0,0)

    45 }

    46 

    47 1;