parse_powerlawcontinuum.cpp

Go to the documentation of this file.

/* This file is part of Cloudy and is copyright (C)1978-2022 by Gary J. Ferland and
 * others.  For conditions of distribution and use see copyright notice in license.txt */
/*ParsePowerlawContinuum parse the power law continuum command */
#include "cddefines.h"
#include "rfield.h"
#include "optimize.h"
#include "input.h"
#include "parser.h"

void ParsePowerlawContinuum(Parser &p)
{
        DEBUG_ENTRY( "ParsePowerlawContinuum()" );

        /* power law with cutoff and X-ray continuum */
        strcpy( rfield.chSpType[rfield.nShape], "POWER" );

        /* first parameter is slope of continuum, probably should be negative */
        rfield.slope[rfield.nShape] = p.FFmtRead();
        if( p.lgEOL() )
        {
                fprintf( ioQQQ, " There should have been a number on this line.   Sorry.\n" );
                cdEXIT(EXIT_FAILURE);
        }

        if( rfield.slope[rfield.nShape] >= 0. )
        {
                fprintf( ioQQQ, " Is the slope of this power law correct?\n" );
        }

        /* second optional parameter is high energy cut off */
        rfield.cutoff[rfield.nShape][0] = p.FFmtRead();

        /* no cutoff if eof hit */
        if( p.lgEOL() )
        {
                /* no extra parameters at all, so put in extreme cutoffs */
                rfield.cutoff[rfield.nShape][0] = 1e4;
                rfield.cutoff[rfield.nShape][1] = 1e-4;
        }
        else
        {
                /* first cutoff was present, check for second */
                rfield.cutoff[rfield.nShape][1] = p.FFmtRead();
                if( p.lgEOL() )
                        rfield.cutoff[rfield.nShape][1] = 1e-4;
        }

        /* check that energies were entered in the correct order */
        if( rfield.cutoff[rfield.nShape][1] > rfield.cutoff[rfield.nShape][0] )
        {
                fprintf( ioQQQ, " The optional cutoff energies do not appear to be in the correct order.  Check Hazy.\n" );
                cdEXIT(EXIT_FAILURE);
        }

        /* check for keyword KELVIN to interpret cutoff energies as degrees */
        if( p.nMatch("KELV") )
        {
                /* temps are log if first le 10 */
                if( rfield.cutoff[rfield.nShape][0] <= 10. || p.nMatch(" LOG") )
                        rfield.cutoff[rfield.nShape][0] = exp10(rfield.cutoff[rfield.nShape][0]);
                if( rfield.cutoff[rfield.nShape][1] <= 10. || p.nMatch(" LOG") )
                        rfield.cutoff[rfield.nShape][1] = exp10(rfield.cutoff[rfield.nShape][1]);
                rfield.cutoff[rfield.nShape][0] /= TE1RYD;
                rfield.cutoff[rfield.nShape][1] /= TE1RYD;
        }

        if( rfield.cutoff[rfield.nShape][0] < 0. || 
                rfield.cutoff[rfield.nShape][1] < 0. )
        {
                fprintf( ioQQQ, " A negative cutoff energy is not physical.  Sorry.\n" );
                cdEXIT(EXIT_FAILURE);
        }

        if( rfield.cutoff[rfield.nShape][1] == 0. && 
                rfield.slope[rfield.nShape] <= -1. )
        {
                fprintf( ioQQQ, " A power-law with this slope, and no low energy cutoff, may have an unphysically large\n brightness temperature in the radio.\n" );
        }

        /* vary option */
        if( optimize.lgVarOn )
        {
                /* pointer to where to write */
                optimize.nvfpnt[optimize.nparm] = input.nRead;
                if( p.nMatch("VARYB") )
                {
                        /* this test is for key "varyb", meaning to vary second parameter
                         * the cutoff temperature
                         * this is the number of parameters to feed onto the input line */
                        optimize.nvarxt[optimize.nparm] = 1;
                        sprintf( optimize.chVarFmt[optimize.nparm], "POWER LAW %f KELVIN %%f %f LOG", 
                                 rfield.slope[rfield.nShape],
                                 log10(rfield.cutoff[rfield.nShape][1]*TE1RYD) );
                        optimize.vparm[0][optimize.nparm] =
                                (realnum)log10(rfield.cutoff[rfield.nShape][0]*TE1RYD);
                        optimize.varang[optimize.nparm][0] = (realnum)log10(rfield.cutoff[rfield.nShape][1]*TE1RYD);
                        optimize.varang[optimize.nparm][1] = FLT_MAX;
                        optimize.vincr[optimize.nparm] = 0.2f;
                }
                else if( p.nMatch("VARYC") )
                {
                        /* the keyword was "varyc"
                         * this is the number of parameters to feed onto the input line */
                        optimize.nvarxt[optimize.nparm] = 1;
                        sprintf( optimize.chVarFmt[optimize.nparm], "POWER LAW %f KELVIN %f %%f LOG", 
                                 rfield.slope[rfield.nShape],
                                 log10(rfield.cutoff[rfield.nShape][0]*TE1RYD) );
                        optimize.vparm[0][optimize.nparm] =
                                (realnum)log10(rfield.cutoff[rfield.nShape][1]*TE1RYD);
                        optimize.varang[optimize.nparm][0] = -FLT_MAX;
                        optimize.varang[optimize.nparm][1] = (realnum)log10(rfield.cutoff[rfield.nShape][0]*TE1RYD);
                        optimize.vincr[optimize.nparm] = 0.2f;
                }
                else
                {
                        /* vary the first parameter only, but still are two more
                         * this is the number of parameters to feed onto the input line */
                        optimize.nvarxt[optimize.nparm] = 1;
                        sprintf( optimize.chVarFmt[optimize.nparm], "POWER LAW %%f KELVIN %f %f LOG", 
                                 log10(rfield.cutoff[rfield.nShape][0]*TE1RYD),
                                 log10(rfield.cutoff[rfield.nShape][1]*TE1RYD) );
                        optimize.vparm[0][optimize.nparm] = (realnum)rfield.slope[rfield.nShape];
                        optimize.vincr[optimize.nparm] = 0.2f;
                }
                ++optimize.nparm;
        }

        /*>>chng 06 nov 10, BUGFIX, nShape was incremented before previous branch
         * and so crashed with log10 0 since nSpage was beyond set values
         * caused fpe domain function error with log 0
         * fpe caught by Pavel Abolmasov */
        ++rfield.nShape;
        if( rfield.nShape >= LIMSPC )
        {
                fprintf( ioQQQ, " Too many continua entered; increase LIMSPC\n" );
                cdEXIT(EXIT_FAILURE);
        }

        return;
}