The HDF_DF24_LASTREF function returns the reference number of the most recently read or written 24-bit image in an HDF file.
Result = HDF_DF24_LASTREF( )
Returns the reference number of the most recently read or written image.
None
None
; Open an HDF file.
h=HDF_OPEN('myhdf.hdf')
PRINT, HDF_DF24_LASTREF()
; IDL prints 0, meaning that the call was successful,
; but no reference number was available.
; Create a 3D array, representing a 24-bit image:
a = BINDGEN(3,100,100)
; Write the 24-bit image to the file:
HDF_DF24_ADDIMAGE, 'myhdf.hdf', a
PRINT, HDF_DF24_LASTREF()
; IDL prints a reference number for the last operation
; (for example, 2). Note the reference number is not
; simply a 1-based "image number"; the reference number
; could easily be "2" or "3", etc.
; Write another image to the file:
HDF_DF24_ADDIMAGE, 'myhdf.hdf', a
; Print the last reference number:
PRINT, HDF_DF24_LASTREF()
PRINT, HDF_DF24_NIMAGES('myhdf.hdf')
; IDL prints "2" because we’ve written two images to the file.
; Close the file
HDF_CLOSE, h
|
4.0 |
Introduced |
HDF_DF24_ADDIMAGE, HDF_DF24_GETIMAGE, HDF_DF24_GETINFO, HDF_DF24_NIMAGES, HDF_DF24_READREF, HDF_DF24_RESTART, HDF_DFR8_LASTREF