PRO dustem_fit_polarization_example,model=model $ ,sed_file=sed_file $ ,Nitermax=Nitermax $ ,postscript=postscript $ ,fits_save=fits_save $ ,help=help $ ,noobj=noobj $ ,wait=wait $ ,verbose=verbose ;+ ; NAME: ; dustem_fit_polarization_example ; ; PURPOSE: ; This is an example of how to fit observational SEDs (with ; measurements in Stokes IQU) using DustEMWrap. ; It is intended as an example to follow when writing your own ; programs to analyse data with DustEMWrap. ; ; CATEGORY: ; DustEMWrap, Distributed, High-Level, User Example ; ; CALLING SEQUENCE: ; dustem_fit_polarization_example[,model=][sed_file=][,postscript=][,Nitermax=][,fits_save=][,/help,/wait,/verbose] ; ; INPUTS: ; None ; ; OPTIONAL INPUT PARAMETERS: ; None ; ; OUTPUTS: ; None ; ; OPTIONAL OUTPUT PARAMETERS: ; Plots, Results save structure in binary FITS table format ; ; ACCEPTED KEY-WORDS: ; model = specifies the interstellar dust mixture used by ; DustEM. See userguide or dustem_test_model_exists.pro ; for more details about available models in current release. ; sed_file = string naming the path to text file in .xcat format that ; describes the observational SED. If not set, the file ; 'Data/EXAMPLE_OBSDATA/example_SED_3.xcat' is used. ; postscript = if set, final plot is saved as postscript file ; Nitermax = maximum number of fit iterations. Default is 5. ; fits_save = if set, saves results in a FITS file. ; help = if set, print this help ; wait = if set, wait this many seconds between each step of ; the code (for illustration purposes) ; verbose = if set, subroutines will run in verbose mode ; COMMON BLOCKS: ; None ; ; SIDE EFFECTS: ; None ; ; RESTRICTIONS: ; The DustEM fortran code must be installed ; The DustEMWrap IDL code must be installed ; ; PROCEDURES AND SUBROUTINES USED: ; ; EXAMPLES ; dustem_fit_polarization_example ; dustem_fit_polarization_example,Nitermax=1,fits_save='/tmp/mysavefile.fits' ; dustem_fit_polarization_example,model='DBP90' ; ; MODIFICATION HISTORY: ; Written by JPB Apr-2022 ; Evolution details on the DustEMWrap gitlab. ; See http://dustemwrap.irap.omp.eu/ for FAQ and help. ;- IF keyword_set(help) THEN BEGIN doc_library,'dustem_fit_polarization_example' goto,the_end END IF keyword_set(model) THEN BEGIN use_model=strupcase(model) ENDIF ELSE BEGIN use_model='G17_MODELD' ;Default is one of the Guillet et al (2017) models since they treat dust polarization properties ENDELSE exists=dustem_test_model_exists(use_model,/pol) if exists ne 1 then $ message,'Unknown/non-polarized dust model: '+use_model use_window=2 ; default graphics window number to use for plotting the results use_verbose=0 if keyword_set(verbose) then use_verbose=1 use_Nitermax=5 ; maximum number of iterations for the fit IF keyword_set(Nitermax) THEN use_Nitermax=Nitermax dustem_define_la_common ;; ;=== AN EXAMPLE FOR G17_MODELA/B/C/D ;; ;=== Here we fit the dust abundances of the model, the dust ;; ;=== polarization and a plug-in: ;; ;=== (i) synchrotron emission (also polarized) ;; ;=== The free parameters in the fit are lower-bounded at ;; ;=== ~zero. The synchrotron parameters are constrained betweem ;; ;=== upper and lower bounds ;; ;=== The intensity of the dust-heating radiation field and the ;; ;=== spectral index of the CRE energy spectrum are fixed. pd = [ $ '(*!dustem_params).grains(0).mdust_o_mh',$ ;PAH0 mass fraction '(*!dustem_params).grains(1).mdust_o_mh',$ ;amorphous carbon mass fraction '(*!dustem_params).grains(2).mdust_o_mh', $ ;amorphous silicate mass fraction 'dustem_plugin_modify_dust_pol_2', $ ;Dust polarization angle 'dustem_plugin_synchrotron_2', $ ;Synchrotron amplitude at 10 mm 'dustem_plugin_synchrotron_3', $ ;Synchrotron polarization fraction 'dustem_plugin_synchrotron_4' $ ;Synchrotron polarization angle ] iv=[7.2e-4,7.2e-4,8.5e-4,-10.,0.015,0.25,35.] Npar=n_elements(pd) ulimed=[0,0,0,0,1,1,1] llimed=[1,1,1,0,1,1,1] ulims=[0,0,0,0,0.02,0.5,60.] llims=[1.e-15,1.e-15,1.e-15,0,0.005,0.05,30.] fpd=[ '(*!dustem_params).G0' , $ ; intensity of the dust-heating radiation field 'dustem_plugin_synchrotron_1'] ;Synchrotron CR spectral index fiv=[1.0,3.0] use_polarization=1 ;Nfix=n_elements(fpd) ;if n_elements(fiv) ne Nfix then begin ; message,'Number of fixed parameters (fpd) does not equal number of initial values of fixed parameters (fiv)',/info ; stop ;end ;== INITIALISE DUSTEM ;dustem_init,mode=use_model,grain_keywords=['logn-chrg-spin','?','plaw-pol'],polarization=1 dustem_init,model=use_model,pol=use_polarization !dustem_verbose=1 ;!dustem_show_plot=1 !dustem_nocatch=1 IF keyword_set(noobj) THEN !dustem_noobj=1 ;=== READ EXAMPLE SED DATA dir=!dustem_wrap_soft_dir+'/Data/EXAMPLE_OBSDATA/' file=dir+'example_SED_3.xcat' IF keyword_set(sed_file) THEN file=sed_file sed=read_xcat(file,/silent) ;== SET THE OBSERVATIONAL STRUCTURE ;== sed is passed twice -- the first occurrence is the SED that you ;== wish to fit, the second occurrence is the SED that you wish to visualise. dustem_set_data,m_fit=sed,m_show=sed ;== SET INITIAL VALUES AND LIMITS OF THE PARAMETERS THAT WILL BE ;== ADJUSTED DURING THE FIT dustem_init_params,use_model,pd,iv,fpd=fpd,fiv=fiv,ulimed=ulimed,llimed=llimed,ulims=ulims,llims=llims,pol=use_polarization ;=== RUN fit ;number of iterations has already been specified in the beginning of the code. tol=1.e-16 xtol=1.e-16 use_Nitermax=5; an initialization IF keyword_set(Nitermax) THEN use_Nitermax=Nitermax xrange=[1.,2.e4] yrange=[1e-4,1.e3] ;Set show_plot to 0 to hide plot ;Commented or set to 1 is the same since !dustem_show_plot (existing sysvar) is initialized to 1 in dustem_init ;show_plot = 0 loadct,13 t1=systime(0,/sec) title='FIT POLARIZATION EXAMPLE' res=dustem_mpfit_data(tol=tol,xtol=xtol,Nitermax=use_Nitermax,xrange=xrange,/xstyle,yrange=yrange $ ,/ysty,/ylog,/xlog,xtit='wavelength [mic]',ytit='Brightness []' $ ,title=title,show_plot=show_plot) t2=systime(0,/sec) if keyword_set(wait) then begin message,'Finished running DustEMWrap, using Niters: '+strtrim(string(use_Nitermax),2),/info message,'Time taken [sec]: '+sigfig(t2-t1,2,/sci),/info wait,wait end ;=== MAKE THE FINAL PLOT IF keyword_set(postscript) THEN BEGIN ; dir_ps='./' mydevice=!d.name set_plot,'PS' ; ps_file=dir_ps+postscript ps_file=postscript device,filename=ps_file,/color ENDIF IF !dustem_noobj THEN BEGIN dustemwrap_plot_noobj,(*(*!dustem_fit).CURRENT_PARAM_VALUES),st=dummy,xr=xr,/xstyle,yr=yr,/ysty,/ylog,/xlog,title=title+' (Final fit)' ENDIF ELSE BEGIN dustemwrap_plot,(*(*!dustem_fit).CURRENT_PARAM_VALUES),st=dummy,xr=xr,/xstyle,yr=yr,/ysty,/ylog,/xlog,title=title+' (Final fit)' ENDELSE IF keyword_set(postscript) THEN BEGIN device,/close set_plot,mydevice message,'Wrote '+ps_file,/info ENDIF if keyword_set(wait) then begin message,'Made the plot of the final results',/info wait,wait end IF keyword_set(fits_save) THEN BEGIN message,'Writing out results structure: '+fits_save,/info dustem_write_fits_table,filename=fits_save,help=help ;=== At this point, you could erase all dustem system variables, or exit idl... all the ;=== information needed to recover the results and remake the plots has been saved in the FITS table ;; dustem_read_fits_table,filename=fits_save,dustem_st=dustem_spectra_st ;; ;==== plot result taken from the saved fits table ;; res=*(*!dustem_fit).CURRENT_PARAM_VALUES ;; ;If the user prefers non-OOP plotting then reset !dustem_noobj=1 here since dustem_init is called in reads_fits_table. ;; IF !dustem_noobj THEN BEGIN ;; dustemwrap_plot_noobj,res,st=dustem_spectra_st,xr=xr,/xstyle,yr=yr,/ysty,/ylog,/xlog,title=title+' (From saved FITS file)' ;; ENDIF ELSE BEGIN ;; dustemwrap_plot,res,st=dustem_spectra_st,xr=xr,/xstyle,yr=yr,/ysty,/ylog,/xlog,title=title+' (From saved FITS file)' ;; ENDELSE if keyword_set(wait) then begin message,'Saved the results as FITS in the file: '+fits_save,/info wait,wait end ENDIF the_end: message,'Finished dustem_polarization_example',/info END