ELF data storage

The ELF package takes a COPY of the DIPSO `current' spectrum. The maximum space available is 1000 datum points. This number is deliberately rather smaller than the space available in DIPSO itself, since fitting to large numbers of datum points is prohibitively time consuming.

Fit data are maintained in three storage areas:

• A `current' area (not to be confused with the DIPSO current arrays) contains the specification of the fit in progress. If an optimisation has been carried out, the results (in the sense of optimised coefficients) are also kept in this `current' array.

• A stack of fit coefficients. Data may be interchanged between this stack (again, not to be confused with the main DIPSO stack) and the ELF `current' area. Space is provided for a maximum of 20 lines in each fit.

• A stack of input numerical profiles. These must be spectrum data without internal breaks (gaps), stored in VELOCITY space.

The stack of profile types has space for up to ten entries. The first five of these are reserved for analytically specified profiles, and the last five for numerical profiles. Profile definition is as follows:

• Profile 1: Gaussian. (C=centre, W=width(FWHM), I=peak flux)
• Profile 2: Triangular. (C=centre, W=width(FWHM), I=peak flux)
• Profile 3-5: Unused at present.
• Profile 6-10: Available for numerical profiles.