Keywords: sic-gdfv2

Next: GDF_TRIM_HEADER Up: GDF API and programming Previous: GILDAS_NULL Contents

## GDF_READ_HEADER

Subroutine `GDF_READ_HEADER` reads the header of the requested Gildas data set (specified in `imag%file`), and optionally change its rank.

    subroutine gdf_read_header(imag,error,rank)
      use gio_dependencies_interfaces
      use gio_interfaces, except_this=>gdf_read_header
      use image_def
      use gbl_message
      !---------------------------------------------------------------------
      ! @ public
      ! GDF API
      !       Read an image header from the requested file
      !---------------------------------------------------------------------
      type(gildas), intent(inout) :: imag   ! Image structure
      logical,      intent(out)   :: error  ! Error flag
      integer,      intent(in), optional :: rank  ! Desired rank

If the optional `rank=value` argument is present, the header is modified according to the following rules. `value < 0` means the image must have `hx%gil%ndim=-rank`. `value = 0` means trim all possible trailine degenerate dimensions, i.e. set `hx%gil%ndim` to the last dimension . `value > 0` means extend or trim rank to desired value.