Dealing with GDF files (any kind)

No access the Gildas derived type elements should be done before calling the subroutine GILDAS_NULL, as some elements are dangling pointers.

  call gildas_null(hx, type)

where hx is the Gildas header to be initialized, and type a character string indicating the desired type of Gildas data structure. type is an optional character string. Recognized values are 'IMAGE', 'TABLE', 'UVT', 'TUV' and 'VOTABLE', in link to the types described in Table 2. The default is set to 'IMAGE'.

• The 4 triplets (refj,valj,incj) (with $j=1 \ to \ 4$) have been removed. For a more generic approach with 7 dimensions, these $4 \times 3$ scalars have been replaced by 3 vectors ref(:), val(:), inc(:) (as described in section 3.2.3).
• Similarly, the 4 pairs (minj,maxj) (with $j=1 \ to \ 4$) have been removed. These $4 \times 2$ scalars have been replaced by 2 vectors minloc(:) and maxloc(:).
• each section length variable has been renamed as detailed in Table 3 (usually by adding the suffix _words to the GDFV1 name). The General information has been split into the 2 sections Dimension and Coordinate. As described in section 3.1.1, any non-zero value is now valid to indicate that a section is enabled for reading or writing.

Table 3: Renaming of section length variables between the GDFV1 and GDFV2. Absent name indicate a section that has appeared or disappeared.

Section	GDFV1	GDFV2
General	gene	-
Dimension	-	dim_words
Blanking	blan	blan_words
Extrema	extr	extr_words
Coordinate	-	coor_words
Description	desc	desc_words
Position	posi	posi_words
Projection	proj	proj_words
Spectroscopy	spec	spec_words
Resolution	reso	reso_words
Noise	sigm	nois_words
Astrometry	prop	astr_words
UV Data	-	uvda_words