From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001 From: Joe Hunkeler Date: Tue, 11 Aug 2015 16:51:37 -0400 Subject: Repatch (from linux) of OSX IRAF --- noao/onedspec/doc/sys/1and2dspec.hlp | 66 ++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 noao/onedspec/doc/sys/1and2dspec.hlp (limited to 'noao/onedspec/doc/sys/1and2dspec.hlp') diff --git a/noao/onedspec/doc/sys/1and2dspec.hlp b/noao/onedspec/doc/sys/1and2dspec.hlp new file mode 100644 index 00000000..01f01763 --- /dev/null +++ b/noao/onedspec/doc/sys/1and2dspec.hlp @@ -0,0 +1,66 @@ +.help onedspec (Oct84) "Spectral Reductions" +.ce +Relationship Between Onedspec and Twodspec +.ce +Discussion +.ce +October 24, 1984 +.sp 3 +Two types of interactions between one dimensional and two dimensional +spectra may be defined: + +.ls (1) +Perform a one dimensional operation on the average or sum of a set +of lines in a two dimensional image. +.le +.ls (2) +Perform a one dimensional operation successively on a set of lines +in a two dimensional image. +.le + +The two functions might be combined as: + +.ls (3) +Perform a one dimensional operation on the average or sum of a set +of lines in a two dimensional image and apply the one dimensional +result successively on a set of lines in a two dimensional image. +.le + +Examples of this are dispersion solutions and flux calibrations for +longslit spectra. + + Some choices for implementation are: + +.ls (1) +Use a 2-D to 1-D operator to create a 1-D spectrum by averaging or summing +lines. +.le +.ls (2) +Use an apply a 1-D arithmetic correction to a 2-D image operator. +Alternatively, expand a 1-D correction to a 2-D correction. +.le +.ls (3) +Convert the 2-D image to a group of 1-D images and provide the 1-D operators +with the ability to perform averaging or summation. +.le +.ls (4) +To perform a one dimensional operation successively on +a set of lines first convert the two dimensional image into a group +of one dimensional spectra. Perform the 1-D operation on the desired +elements of the group and then reconstruct the 2-D image from the group +of 1-D images. +.le +.ls (5) +Built separate operators for 2-D images using the 1-D subroutines. +.le +.ls (6) +Provide the ability in the 1-D operators to perform the desired 2-D +operations directly. +.le + + Options (1) and (2) are essentially what is done on the IPPS. Option (5) +would lessen the amount of development but increase the number of tasks +to be written. I find option (6) desirable because of its +increased generality but it would require a +further definition of the data structures allowed and the syntax. +.endhelp -- cgit