yp2d

yp2d

stsdas.hst_calib.fos

yp2d

NAME · USAGE · DESCRIPTION · PARAMETERS · EXAMPLES · BUGS · REFERENCES
HELP · SEE_ALSO

NAME

yp2d -- Convert from image pixel number to FOS diode number.

yp2d is a script to help determine which diodes contribute to a specific pixel. The pattern information can either be obtained from an observation or from the task parameters. Pixels can be anything greater than 0; i.e. if an observation has more than one YSTEP, pixels will exist greater than 2064. These numbers can be entered without needing to convert.

Either a single pixel can be converted, or a file containing a list of pixels can be converted. The range of diodes are written to the task parameters dbeg and dend. In case of a list, only the last pixel in the list will be reflected in the parameters.

yp2d can also produce text output to standard output. The form of the text output is suitable for other tasks that use tables as input.

If a file is specified, it is expected to contain one column of pixel numbers. Comment lines are allowed.

PARAMETERS

pixel [int]: The pixel number to convert. If a file is specified in the parameter plist, the value in this parameter will not be used.

(obs = "") [file]: The name of an FOS observation to retrieve the pattern information from. If blank, the pattern information is taken from the parameters nxsteps, overscan, fchnl, nchnls.

(plist = "") [file]: The name of a text file containing a list of pixels to convert. The file should contain one column of pixel numbers. Lines beginning with "#" are considered comment lines and ignored.

(nxsteps = 4) [int]: If no observation is specified, the NXSTEPS desired is retrieved from this parameter.

(overscan = 5) [int]: If no observation is specified, the OVERSCAN desired is retrieved from this parameter.

(fchnl = 1) [int]: If no observation is specified, the first channel, or diode, that is read. This is necessary to modify if the wavelength range is meant to be restricted. This is used in conjunction with the nchnls parameter.

(nchnls = 512) [int]: If no observation is specified, the number of channels, or diodes, to be read. This is necessary to modify if the wavelength range is meant to be restricted. This is used in conjunction with the fcnhl parameter.

(dbeg) [int]: An output parameter. On task completion, this will be the first diode which contributes to the specified pixel. If a pixel list was given, this will contain the beginning diode for the last pixel in the list.

(dend) [int]: An output parameter. On task completion, this will be the last diode which contributes to the specified pixel. If a pixel list was given, this will contain the end diode for the last pixel in the list.

(verbose = yes) [bool]: Tells whether the results of the conversion should be written to standard output in table form.

EXAMPLES

1. Determine which diodes contribute to pixel 364

	cl> yp2d 364
	# yp2d: nxsteps = 4 overscan = 5 fchnl = 1 nchnls = 512
	# pixel  dbeg  dend
	    364    87    91
	cl> lpar yp2d
	        pixel = 364  Input pixel number
	         (obs = "")  Observation to get step pattern from
	       (plist = "")  File containing a list of pixels to convert
	     (nxsteps = 4)   NX steps if no obs specified
	    (overscan = 5)   OVERSCAN if no obs specified
	       (fchnl = 1)   First channel (diode) to be read
	      (nchnls = 512) Number of channels (diodes) to be read
	        (dbeg = 87)  Output: First diode contributing to pixel
	        (dend = 91)  Output: Last diode contributing to pixel
	     (verbose = yes) Write results to standard output

2. Determine diodes for a list of pixels.

	cl> for (i=1000; i<1500; i=i+5) print (i, >> "plist.txt")
	cl> yp2d plist=plist.txt
	# yp2d: nxsteps = 4 overscan = 5 fchnl = 1 nchnls = 512
	# pixel  dbeg  dend
	   1000   246   250
	   1005   248   252
	   1010   249   253
	...

3. Get the pattern information from an observation.

	cl> yp2d 364 obs=y2observ.c1h