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diff --git a/noao/rv/doc/continpars.hlp b/noao/rv/doc/continpars.hlp new file mode 100644 index 00000000..17f9badf --- /dev/null +++ b/noao/rv/doc/continpars.hlp @@ -0,0 +1,129 @@ +.help continpars Jan92 noao.rv +.ih +NAME +continpars -- edit the continuum subtraction parameters +.ih +USAGE +continpars +.ih +PARAMETERS +.ls c_sample = "*" +Lines or columns to be used in the fits. The default value ("*") selects +all pixels. Type \fIhelp ranges\fR for a complete description of the +syntax. +.le +.ls c_function = "spline3" +Continuum function to be fit to the image lines or columns. The functions are +"legendre" (Legendre polynomial), "chebyshev" (Chebyshev polynomial), +"spline1" (linear spline), and "spline3" (cubic spline). The functions +may be abbreviated. +.le +.ls c_interactive = "no" +Interactively fit the continuum? If set to yes, each spectrum will be fit +interactively as they are read into the task if the \fIfxcor.continuum\fR +parameter requires it. The \fIfxcor\fR keystroke commands 'o' and 't' will +automatically fit the continuum interactively. +.le +.ls naverage = 1 +Number of sample points to combined to create a fitting point. +A positive value specifies an average and a negative value specifies +a median. +.le +.ls order = 1 +The order of the polynomials or the number of spline pieces. +.le +.ls replace = no +Replace rejected data points with continuum fit points prior to the +subtraction? If set to yes, points lying outside the \fIlow_reject\fR or +\fIhigh_reject\fR limits are replaced by the fit values prior to the +continuum subtraction. This can be useful in removing emission features +or cosmic ray events, but great care must be taken in setting other parameters +in order to get satisfactory results. Adjusting the \fIgrow\fR or +\fIaverage\fR parameters, and using a low order function usually provide +a good result. +.le +.ls low_reject = 2., high_reject = 2. +Rejection limits below and above the fit in units of the residual sigma. +.le +.ls niterate = 1 +Number of rejection iterations. +.le +.ls grow = 1. +When a pixel is rejected, pixels within this distance of the rejected pixel +are also rejected. +.le + +.ih +DESCRIPTION +The \fIcontinpars\fR pset is used to control the continuum subtraction from +the data. When the \fIfxcor\fR task is run in a batch mode, +the parameters are used to +automatically process the data without intervention from the user. In an +interactive session, the user may experiment with different parameter values by +changing them with the allowed colon commands. + +Continuum subtraction is done exactly as with the \fIonedspec.continuum\fR +task. (Details of the operation are described in the \fIcontinuum\fR +documentation.) The fit to the spectra is subtracted from the data, thus +producing a continuum subtracted spectrum suitable for input to the correlation +routines. + +Users who require the full ability of the \fIonedspec.continuum\fR task to +supply another form of output spectrum, such as the ratio of the fit, or +who wish to make use of the "clean" option, should use that task and disable +continuum subtraction in the \fIrv\fR package tasks. More functionality is +planned for this pset in the future. + +.ih +TASK COLON COMMANDS +The values of the \fIcontinpars\fR pset may be changed, displayed, or updated +from within tasks that use them by means of various colon commands. Simply +typing the parameter name will have the default action of printing the current +value of that parameter. +.ls :unlearn continpars +Reset the continpars pset parameters with their default values. +The argument "continpars" must be present or else the command will default +to the \fIfxcor\fR task command. +.le +.ls :update continpars +Update the continpars pset parameters with the current values. +The argument "continpars" must be present or else the command will default +to the \fIfxcor\fR task command. +.le +.ls :show continpars +Show the current values of the continpars pset parameters. +The argument "continpars" must be present or else the command will default +to the \fIfxcor\fR task command. +.le + +The following parameters will be displayed if it's name it typed, and a new +value accepted if an argument is given. + +.nf +:c_sample [range_string] +:naverage [int_value] +:c_function [spline3|legendre|chebyshev|spline1] +:order [int_value] +:low_reject [int_value] +:high_reject [int_value] +:niterate [int_value] +:grow [int_value] +.fi + +.ih +EXAMPLES +1. List the continuum parameters. + +.nf + rv> lpar continpars +.fi + +2. Edit the continuum parameters + +.nf + rv> continpars +.fi +.ih +SEE ALSO +fxcor, onedspec.continuum, icfit, sfit +.endhelp |