STScI Logo

bplot noao.onedspec



bplot -- Plot spectra noninteractively using SPLOT


bplot images [records]


List of images to be plotted. These may be one dimensional, multiaperture, long slit, or nonspectral images.
records (imred.irs and imred.iids only)
List of records records to be appended to the input image root names when using record number extension format. The syntax of this list is comma separated record numbers or ranges of record numbers. A range consists of two numbers separated by a hyphen. A null list may be used if no record number extensions are desired.
apertures = ""
List of apertures/lines/columns to be plotted in each image. If apertures is null all of the apertures/lines/columns will be plotted.
band = 1
The band or plane of a three dimensional image to be plotted in each image.
graphics = "stdgraph"
Output graphics device. This may be one of "stdgraph", "stdplot", "stdvdm", or the actual device name.
cursor = "onedspec$gcurval.dat"
File(s) containing cursor commands for the SPLOT task. The files will be cycled sequentially. If there is more than one file usually the number of files will agree with the number of apertures for each image since otherwise different cursor/aperture pairings will occur. The default is a file containing only the (q)uit command.

The following parameters are used in response to particular keystrokes. In splot they are query parameters but in bplot they are hidden parameters.

next_image = ""
In response to g (get next image) this parameter specifies the image.
new_image = ""
In response to i (write current spectrum) this parameter specifies the name of a new image to create or existing image to overwrite.
overwrite = yes
Overwrite an existing output image? If set to yes it is possible to write back into the input spectrum or to some other existing image. Otherwise the user is queried again for a new image name.
spec= ""
When adding, subtracting, multiplying, or dividing by a second spectrum (+, -, *, / keys in the f mode) this parameter is used to get the name of the second spectrum.
constant = 0.
When adding or multiplying by a constant (p or m keys in the f mode) the parameter is used to get the constant.
wavelength = 0.
This parameter is used to get a dispersion coordinate value during deblending or when changing the dispersion coordinates with u.
linelist = ""
During deblending this parameter is used to get a list of line positions and widths.
wstart = 0., wend = 0., dw = 0.
In response to p (convert to a linear wavelength scale) these parameter specify the starting wavelength, ending wavelength, and wavelength per pixel.
boxsize = 2
In response to s (smooth) this parameter specifies the box size in pixels to be used for the boxcar smooth


The spectra in the input image list are successively processed by the task splot with input supplied by the cursor parameter and the output sent to the specified graphics device. The range of apertures and bands specified by apertures and bands will be processed for each image. In the iids/irs packages the record extension syntax is used with input root names and a record number list. The hidden parameters from splot apply to this task.

The cursor file(s) consists of line(s) of the form:

[x y 1] key [command]

where x and y are the position of the cursor (may be zero or absent if the cursor position is irrelevant) and key is one of the keystrokes understood by splot . If the key is ":" then the colon command string follows. The default cursor file consists of the single line:

0 0 1 q

If more than one cursor file is specified they are sequentially assigned to each aperture and the list is repeated as needed. This allows the aperture to be manipulated in differing ways.


1. To plot all of apertures of the multiaperture spectra indicated by the file "nite1.lst" on the default plotter and run in the background:

    cl> bplot @nite1.lst graphics=stdplot &

2. To preview the plots:

    cl> bplot @nite1.lst graphics=stdgraph

3. To produce a histogram type plot about Balmer alpha for aperture 5 of each spectrum with the IRAF banner suppressed:

    cl> type curfile
    6555 0 1 a
    6570 0 1 a
    cl> splot.options="auto hist nosysid"
    cl> splot.xmin=6555
    cl> splot.xmax=6570
    cl> bplot @nite1.lst apertures=5 cursor=curfile

4. To produce plots with four spectra per page:

    cl> bplot @nite1.lst ... >G
    cl> gkimosaic dev=stdplot

The first command redirects the output of the graphics to the metacode file The task gkimosaic is used to make multiple plots per page. Other tasks in the plot package may be used to manipulate and redisplay the contents of the metacode file.

5. To plot a list of apertures with a different cursor file for each aperture:

    cl> bplot @nite1.lst apertures=3,9,14 cursor=@nite1.cur

In this case the file "nite1.cur" is assumed to be a list of individual cursor file names, for instance:


that are in one to one correspondence with the range of apertures.


BPLOT V2.10.3
The query parameters from SPLOT were added as hidden parameters in BPLOT to allow use of those keys in a batch way.
The apertures and band parameters been added to select apertures from multiple spectra and long slit images, and bands from 3D images. Since the task is a script calling splot , the many revisions to that task also apply. The version in the irs/iids packages selects spectra using the record number extension syntax.


The cursor file command keystrokes cannot include any of the cursor mode (CAPITALIZED) keys. This results from the implementation of the cursor mode commands as external to both BPLOT and SPLOT.

When first entered, SPLOT will always display an initial plot. BPLOT calls SPLOT once for each aperture in each image and thus produces N(apertures)*N(images) initial plots. The plots are not optional because of the possible confusion a blank screen might cause an inexperienced user. If the initial plots are unwanted they must be edited out of the graphics stream. This can be done as follows, by directing the graphics output of BPLOT to a metacode file and then using GKIEXTRACT to remove only the desired plots from the metacode file:

    cl> bplot @nite1.lst cursor=curfile >G
    cl> gkiextract 2x2 | gkimosaic dev=stdplot

This assumes that curfile is designed to produce only one plot in addition to the non-optional initial plot. In this case there will be two plots per aperture per image and we extract every other plot starting with the second (as encoded in the range string: "2x2").


splot, specplot, slist, gkiextract, gkimosaic, implot, graph, ranges

Source Code · Search Form · STSDAS