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Diffstat (limited to 'pkg/obsolete/fits/structure.hlp')
| -rw-r--r-- | pkg/obsolete/fits/structure.hlp | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/pkg/obsolete/fits/structure.hlp b/pkg/obsolete/fits/structure.hlp new file mode 100644 index 00000000..715ef185 --- /dev/null +++ b/pkg/obsolete/fits/structure.hlp @@ -0,0 +1,363 @@ +.help fits Apr84 "Program Structure" +.sh +RFITS Structure Chart + +.nf +t_rfits () +# Returns when file list is satisfied or if EOT is encountered +# Errors from called routines are trapped and printed as a warning. + + read_fits (fitsfile, iraffile) + # Returns OK or EOF + + read_header (fits_fd, fits, im) + # Returns OK or EOF + + decode_fits_card (fits, im, card) + # Returns YES or NO + + get_fits_string (card, str, maxchar) + + read_image (fits_fd, fits, im) + # Invokes error handler if EOF is encountered + + set_image_header (fits, im) + + set_coords (im) + # sets the coordinate transformations to a 1 to 1 + # mapping + + init_read_pixels (npix_record, bitpix, lsbf, spp_type) + # Returns OK + + put_imageline (im, bufptr, v, pixel_type) + # Outputs line to image + + read_pixels (fd, buffer, npix) + # Returns EOF or the number of pixels converted + + map_blanks (a, blanks, im) + + scale_line (line, bufptr, npix, bscale, bzero, + pixel_type) + # Converts the pixels to the output data type after + # applying bscale and bzero to the data + + change_line(line, bufptr, npix, pixel_type) + # Changes the FITS integers to the output pixel_type + # without scaling. +.fi + +.sh +RFITS Structure Summary + +.ls 4 t_rfits +The main procedure reads the control parameters. +The files to be read and converted are calculated from the specified source +and file list. A loop through +the files determines the specific input source names and output filenames +and calls READ_FITS for each conversion. +.ls read_fits +The input source is opened and the output image header file is created. +If only the FITS header is to be listed then a temporary image header file +is created. The FITS header is read and decoded into the IRAF image +header by READ_HEADER. If the image is to be read then MAKE_IMAGE is +called. Finally, all files are closed. If a temporary image header file +was created it is deleted. +.ls read_header +Some initialization is done on the IRAF header. +The FITS header cards are read one at a time. If EOF is encountered +then EOF is returned. If a long header listing has been specified then +the card is printed. The card is passed to DECODE_FITS_CARD. If +DECODE_FITS_CARD returns YES for the END card then the loop exits. If a +short header listing has bee specified then the title and image size +is printed. The routine returns OK if the header was successfully +interpreted or EOF if encountered. All other errors are returned +via the error handler. +.ls decode_fits_card +A series of STRMATCHes are made against the recognized FITS keywords. +If a match is found the possible actions are: +.ls +Convert a value to the IRAF image header. The conversions are defined in +fits.h +.le +.ls +Invoke an error condition +.le +.ls +Return a YES status if the keyword is END +.le + +Otherwise, the card is concatenated to the User Area of the IRAF image +header. If the keyword was not END then NO is returned. +.ls get_fits_string +The string field for a keyword with a string value is extracted. The +leading and trailing quotes are removed as well as trailing blanks. +The EOS is marked by either ', /, or the end of the card. +.le +.le +.le +.ls read_image +The FITS image pixels are converted to an IRAF image file. +The image file header is set. +The lines of the image are converted one at a time. +Each line is checked for blank values. +When all the image data has been read the number of blank pixels encounter +is printed (unless the value is zero). +.ls set_image_header +The pixel type for the IRAF image is set to the user specified type. +If no type has been specified then the type is determined from the number +of bits per pixel given in the FITS header. +.le +.ls set_coords +Sets the coordinate transformation parameters to a 1 to 1 transformation. +.le +.ls init_read_pixels +The pixel reading routine is initialized. The parameters are the number +of pixels per record, the number of bits per pixel which must be a +valid MII type, a byte order flag, and the SPP data type to be converted +to. In the FITS reader the byte order is specified to be most significant +byte first and the SPP data type is TY_LONG. +.le +.ls put_imageline +Put_imageline outputs a single line of the FITS image to the IRAF image. +.le +.ls read_pixels +The pixels are read into a record buffer. Data conversion is accomplished +with the MII routines since FITS format is the same as MII format. The +specified number of pixels is returned in the specified buffer. +.le +.ls map_blanks +Pixels having the blank value as given in the FITS header are added into +the bad pixel count in the image header. This routine will someday handle +mapping of bad pixels in a more detailed manner. +.le +.ls scale_line +The FITS integers from tape are converted to the output IRAF data type by +applying the FITS scaling parameters BSCALE and BZERO. +.le +.ls change_line +The FITS integers are converted directly to the output IRAF data type +without scaling (BSCALE = 1.0 and BZERO = 0.0). +.le +.le +.le + +.sh +WFITS Structure Chart + +.nf +t_wfits() +# Returns when the input file list is satisfied. +# Errors from called routines are trapped, an error message is issued and +# wfits terminates. + + wrt_fits (iraf_file, fits_file) + + data_limits (im) + + wrt_header (im, fits, fits_fd) + + set_bitbix (bitpix, pixtype, data_bitpix) + + iraf_type (pixtype, pixstring) + + set_scale (fits_bitpix, datamax, datamin, bscale, bzero) + + tape_limits (fits_bitpix, tapemax, tapemin) + + set_blank (fits_bitpix, blank, blankstr) + + init_wrt_pixels (npix_record, spp_type, mii_type) + + init_card_encode (im, fits) + # Returns YES + + card_encode (im, fits, card) + # Returns YES if valid FITS card + + get_standard_card (cardno, im, fits, axisno, + card + # Returns YES or NO + + get_option_card (im, fits, optiono, card) + # Returns YES or NO + + get_coord_card (im, coordno, coordaxis, card) + # Returns YES or NO + + get_history_card (im, histptr, card) + # Returns YES or NO + + get_end_card (card) + # Returns YES or NO + + wrt_pixels (fits_fd, card, len_card) + + wrt_last_record (fits_fd) + + wrt_image (im, fits, fits_fd) + + init_wrt_pixels (npix_record, spp_type, mii_type) + + get_image_line (im, bufptr, v, pixtype) + # Returns EOF or number of pixels in a line + + scale_line (bufptr, long_array, npix, bscale, bzero, + pixtype) + + long_line (bufptr, long_array, npix, pixtype) + + map_blanks (im, long_array, blank) + + wrt_pixels (fits_fd, long_array, npix) + + wrt_last_record (fits_fd) +.fi +.sh +WFITS Structure Summary + +.ls t_wfits +The main procedure reads the control parameters. The files to be read and +converted are calculated from the specified source and file list. A loop +through the files determines the specific input source names and output +file names and calls WRT_FITS for each file conversion. Write errors are trapped +and cause termination of the program. +.ls wrt_fits +The input source is opened. If the make_image switch is set the output +destination is opened. The IRAF image header parameters are encoded into +the FITS header and both header and pixels are written to the output +destination. +DATA_LIMITS is called if the autoscale switch is enabled and the IRAF image +data maximum and minimum values are unknown or the image has been modified +since they were last calculated. +If the make_image switch is turned off the FITS header is printed +on the standard output and a temporary output file is created. Finally +all the files are closed. If a temporary file was created it is deleted. +.ls data_limits +DATA_LIMITS calculates the minimum and maximum data values in an IRAF image. +The calculation is made only if these values are +undefined or the image has been modified since the last values were +calculated. +.le +.ls wrt_header +Some initialization is done on the FITS header. The appropriate FITS bitpix, +bzero and bscale factors, and the tape value for blank pixels are calculated +for each image. +The FITS header cards are encoded one at a time. If a long_header listing +has been specified then the FITS card is printed on the standard output. +If a short_header listing +is specified then the title and image size only are printed. Encoding terminates +when the FITS END keyword is encountered. Partial header records are filled +with blanks before being written to the output destination. +.ls set_bitpix +The value of the FITS bitpix is calculated. If the user given bitpix is +not a valid FITS bitpix, SET_BITPIX uses the precision of the IRAF image data +to set bitpix. +.le +.ls iraf_type +The IRAF datatype value is set to either INTEGER, FLOATING or COMPLEX. +.le +.ls set_scale +The bscale and bzero values are calculated from the IRAF minimum and maximum +data values and the FITS bitpix. +.ls tape_limits +The maximum and minimum FITS integer values are calculated from the FITS bitpix. +.le +.le +.ls set_blank +The FITS integer value for a blank pixel is calculated from the FITS bitpix. +.le +.ls init_wrt_pixels +The pixel writing routine is initialized. The parameters are the number of +pixels per record, the spp_type and the number of bits per pixel which +must be a valid mii type. For ASCII header card images the number of pixels +per record is normally 2880 and the bits per pixel is 8. The spp type is +always TY_CHAR. +.le +.ls init_card_encode +The card encoding procedure is initialized. The number of standard keyword, +optional keywords, coordinate transformation keywords, and history keywords +are calculated. +.le +.ls card_encode +An eighty character FITS format string is created for each permitted +FITS keyword. +.ls get_standard_card +The minimum required FITS header parameters, SIMPLE, BITPIX, NAXIS and NAXIS# +are encode into FITS cards. +.le +.ls get_option_card +A set of optional FITS parameters are encoded into FITS cards. +At present the permitted keywords are BSCALE, BZERO, BUNIT, BLANK +OBJECT, ORIGIN, DATE, IRAFMAX, IRAFMIN, IRAF-B/P, and IRAFTYPE. +The BLANK card is only encoded if the number of bad pixels in the +IRAF image header is nonzero. BUNIT and OBJECT cards are only encoded if +if the appropriate strings in the IRAF image header are defined. +.le +.ls get_coord_card +The coordinate transformation parameters are encoded into FITS header cards. +.le +.ls get_history_card +The IRAF history string is encoded into FITS header card(s). A maximum of +seven HISTORY cards are currently permitted by imio. +.le +.ls get_end_card +The FITS end card in encoded. +.le +.le +.ls wrt_pixels +The FITS card images are read into a record buffer. When the buffer is +full data conversion is accomplished using the mii routines since FITS +format is the same as mii format. After data conversion the record +buffer is written to the output destination. +.le +.ls wrt_last_record +The last partially filled header record is padded with blanks and written to +the output destination. +.le +.le +.ls wrt_image +The IRAF image pixels are converted to FITS image format. The lines of the +IRAF image are converted one at a time. Each line is scaled (if scaling is +enabled and appropriate) and the IRAF pixels are converted to long integers. +WRT_PIXELS is called to convert the integers to the appropriate FITS +output type using the MII routines. +.ls init_wrt_pixels +The pixel writing routine is initialized. The parameters are the number of +pixels per output record, the spp type and the number of FITS bits per pixel +which must be a valid mii type. The number of pixels per output record is +2880, 1440 or 720 for FITS bitpix of 8, 16 or 32 respectively. The spp type +is always TY_LONG. +.le +.ls get_image_line +A single IRAF image line is read into an internal buffer. +.le +.ls scale_line +The IRAF image line is scaled by the FITS BSCALE and +BZERO scaling factors and converted to long integers. +SCALE_LINE is called if the scale switch is set. +.le +.ls long_line +The IRAF image data values are converted directly to long integers. +LONG_LINE is called if scaling switch is turned off. +.le +.ls map_blanks +This function will eventually map IRAF blank pixels to the appropriate +FITS integer for blanks. Implementation of this function is will occur +after the imio mods. +.le +.ls wrt_pixels +The scaled IRAF image lines are read into a record buffer. When the buffer is +full data conversion is accomplished using the MII routines since FITS +format is the same as mii format. After data conversion the record +buffer is written to the output destination. +.le +.ls wrt_last_record +The last partially full data record is padded with zeros and written to the +output destination. +.le +.le +.le +.le +.endhelp |