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LINES
FIT\LINES [N [Guesses]] [/NOCURSOR] [/INPUT File_Name] [/SHOW]
Enter the initial values for the profile fit. If argument "AUTO" is
given instead of a number, then the number of lines found in the last
read spectrum will be used for ITERATE command.
If N is not specified, then the last value for N is used. If N is 0,
MINIMIZE will attempt to guess initial values for a single line by com-
puting the moments of the spectrum. If N is not 0, the user has to pro-
vide the initial values for line parameters. N is limited to 10. These
values should be separated by spaces and can be entered as SIC expres-
sions as follows:
Method Code,Value Code,Value Code,Value Code,Value
GAUSS Temperature Position Width
SHELL Area (K.MHz) Offset (MHz) Width (MHz) Horn/Center
NH3 Temperature Position Width (km/s) Opacity
HFS Temperature Position Width (km/s) Opacity
ABSORPTION Opacity Position Width
(no initial guess is needed for the continuum level)
The code is an integer interpreted as follows :
0 adjustable parameter
1 fixed parameter
2 adjustable parameter (head of group)
3 parameter fixed with respect to parameter coded 2 or 4
4 fixed parameter (head of group)
Codes 2 3 and 4 are used to fit dependent lines (e.g. HCN, for which the
displacements are 4.842 and -7.064 km/s, or -1.431 and 2.088 MHz, and
line ratios 1:0.6:0.2). Codes 0 and 1 only are allowed for NH3 method.
The value for a parameter with code 3 should be either the ratio to the
head of group value (for both intensity and width), or the offset from
head of group (for the position).
There are 4 possibilities for the user to provide the line parameters:
LINES /INPUT File_Name
Guesses are read from the input file. "Free" format is used to
read in this input file. The first line must contain the number
of lines, others are as the input at the keyboard.
LINES N "Code Val ..." "Code Val ..." ...
The guesses can also be entered from the command line, as dou-
ble-quoted strings (one string per fitted line), e.g.
LINES 2 "0 0.20 0 0.00 0 25.00" "0 0.10 0 0.00 0 50.00"
LINES N
If the cursor is available, you will have to set interactively
on the plot the boundaries of the N lines. The program then com-
putes the moments of the spectra between these boundaries as in-
put values. The codes are all set to 0 (free parameters) in this
way which is meaningfull ONLY FOR FREE and INDEPENDENT lines.
This cursor selection is not used if you specify the /NOCURSOR
option.
LINES N /NOCURSOR
If none of the 3 methods above is used, then the user is prompt-
ed in the terminal for the guesses. The parameters must be en-
tered together, separated by blanks, one set of guesses per
prompt line.
The option /SHOW can be used for a feedback of what initial guesses have
just been defined.
Command LINES is not supported for method CONTINUUM.
Gildas manager
2024-03-29