use: accum
parameters: none
options:
-help produce help message -weight teff|time|none choose weighting method
description: The scan currently held by time/Tsysˆ2. The result is stored in average
before using show. The result of accum stays in zero.
Option -weight time leads to weighting factors proportinal to the
integration time only and -weight none produces simple adding of channel
contents of
needs:
use: area
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval
description: Calculate integrated intensities between min
and max (or over whole spectra if no option is used). Several
ranges, up to five, may be specified by repeating the option (see example below).
The results will be expressed in the unit used for the limits and will
be logged to file
logfile
in the following format:
AREA: nnnn offx offy area1 area2 ...
nnnn is the scan number, offx and offy are the
map offsets in arcmin for the scan and arean is the result
of the integration for the nth interval.
example: calculate integrated intensities for velocity ranges 10 -- 20, 20 -- 30 and 30 -- 40 km/s. Results will be in K*km/s.
area -vel 10 20 -vel 20 30 -vel 30 40
needs:
see also: moment
use: average
parameters: none
options:
-help produce help message
description: The scan currently held by
example: make an average of scans 1000 and 1010 and show it
zero get 1000; accum get 1010; accum average show
needs:
use: baseline
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval -order n choose order of baseline fit
description: Fit a polynomial to scan data, optionally defining
a range of channels for fitting. The range may be specified in
velocity, frequency or channels by using the respective option. It
defaults to the complete spectrum. Several ranges, up to five, may be specified by
repeating the option. The scan, with the channel data replaced by the
values of the polynomial fit, is stored at subtract to do that. You may plot
the result of baseline by using showfit.
example: fit cubic curve to scan, given two velocity ranges and subtract the fit.
baseline -vel -50.0 0.0 -vel 10.0 60.0 -order 3; subtract
needs:
use: bias value
parameters:
value the bias value to be added to all channels
options:
-help produce help message
description: A constant is added to all channels of the scan
currently held by
example: subtract 1.5 from all channels
bias -1.5
needs:
see also: scale
use: calc
parameters: none
options:
-help produce help message -add add <sf/CTEMP/ to <sf/CWORK/ -subtract subtract <sf/CTEMP/ from <sf/CWORK/ -multiply multiply <sf/CWORK/ by <sf/CTEMP/ -divide divide <sf/CWORK/ by <sf/CTEMP/
description: Perform basic arithmetics with data in
example: calculate the ratio of two scans, channel by channel
get -file scan1 tcopy get -file scan2 calc -divide
needs:
use: clip
parameters: none
options:
-help produce help message -min value specify minimum temperature -max value specify maximum temperature
description: The spectrum is compared against one or two values.
Channels exceeding the limits are cut back to max or min,
respectively. Useful for getting rid of spikes or to investigate weak
features in spectra that are dominated by strong lines. The clipped
spectrum is returned to show command instead.
example: clip channel values $ge 1.0$ and $le -1.0$
clip -min -1.0 -max 1.0
needs:
see also: drop
use: convolve
parameters: none
options:
-help produce help message
description: Convolve the spectra currently held by
needs:
use: correlate
parameters: none
options:
-help produce help message
description: Calculate the correlation spectrum of
needs:
use: data
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval -column n choose number of columns
description: To display the values of channels on the screen.
For each channel within the given region, the velocity, frequency or
channel number is displayed together with its associated temperature
value. The output is formatted into several columns, the number of which
may be set by the -column option (default 8).
example: display channels 1000 to 1100 as 2 column table
data -chan 1000 1100 -column 2
needs:
see also:
use: drop
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval
description: To drop any channels outside the specified range.
This is a permanent loss of channels, show command.
example: drop all channels outside -50.0 to 50.0 km/s
drop -vel -50 50
needs:
see also: clip
use: fft
parameters: none
options:
-help produce help message -invert perform inverse transformation -power calculate periodogram
description: Performs a fast Fourier transform of the
current spectrum. The inverse transform may be performed by specifying
option -invert. You may also get a periodogram (power spectrum) by using the -power option.
needs:
see also: convolve , correlate
use: filter
parameters: none
options:
-help produce help message -boxcard n apply (2n-1)-channel boxcar filter -hanning apply hanning [1/4 1/2 1/4] filter -dispo m n apply m-th order, n channel least-squares filter -coeff n a[0]...a[n-1] specify your own filter (one half)
description: Apply a digital filter to your spectrum which can
be described by 2n+1 filter coefficients
a[-n+1]...a[0]...a[n-1],
which are symmetric around a[0]. The resulting spectrum
will be the convolution of the original data with this filter. Because
boxcar and hanning smoothing are so popular, they have been
preprogrammed and can be invoked through the respective option.
If the filter coefficients aren't normalized, i.e. don't sum up to 1,
filter will do the normalization for you before applying the filter
to the spectrum.
For documentation on least-squares filters see: Numerical recipes, 2nd
edition.
example: convolve spectrum with a 5 (=2$times$3$-$1) channel wide boxcar filter
filter -boxcar 3
needs:
use: fitscube
parameters: none
options:
-help produce help message -file filename specify output filename (default: source.cube) -magnify m fill in m addititional pixels between grid positions -smooth n smooth resulting map n times
description: The program scans through logfile , tries to read a scan for every scan number in the first column and merges these scans into a 3~dimensional, AIPS compatible, FITS formatted cube, where the first axis is velocity and the positional offsets are taken as the second and third axis. Because AIPS doesn't like maps with few pixels, the resulting cube may be interpolated along axis two and three to yield more pixels in each velocity plane. Each plane may be smoothed by applying a laplacian digital filter a given number of times.
example: produce a cube map from a number of scans, which are
assumed to correspond to different map positions around a source.
Because fitscube extracts scan numbers from
logfile
, we
need to generate these entries first. (Any of the commands writing to
logfile
will do, we use the area command in our example.
Each plane of the resulting cube is interpolated to yield a 5-fold
increase in the number of pixels along the spatial axes. The example
assumes that
logfile
is an empty file to start with. The
resulting FITS file will be called HH56.CUBE.
foreach scan (HH56.*) get -file $scan area end fitscube -magnify 5
needs:
see also: fitsmap
use: fitsmap
parameters: none
options:
-help produce help message -file filename specify output filename (default: source.MAP) -col n specify column number in drp.log to map -magnify m fill in m addititional pixels between grid positions -smooth n smooth resulting map n times
description: The results of previous calculations, which were
stored in
logfile
, may be used to produce a 2~dimensional, AIPS
compatible, FITS formatted map, where the positional offsets stored in
logfile
are taken as the x- and y-axis and the entries from an
arbitrary column are taken as the pixel value. The column number is taken
relative to the logged offsets, i.e. col 1 will actually
access column 5 of
logfile
. Because AIPS doesn't
like maps with few pixels, the resulting map may be interpolated along
the spatial axes to yield more pixels. The map may be
smoothed by applying a laplacian digital filter a given number of
times.
example: produce spatial map of line widths resulting from
fitting of gaussian profiles to a number of scans, which are assumed
to correspond to different map positions around a source. The map is
interpolated to yield a 5-fold increase in the number of pixels along
each axis. The example assumes that
logfile
is an empty file to
start with. It is also assumed that the line profiles are so prominent
in all scans, that automatic locating of the line in gauss
works. The line width is returned as the third result by gauss.
The resulting FITS file will be called HH56.MAP.
foreach scan (HH56.*) get -file $scan gauss end fitsmap -col 3 -magnify 5
needs:
see also: fitscube
use: fold
parameters: none
options:
-help produce help message -throw value specify frequency throw -shift shift resulting spectrum by half the throw
description: This command is meant to be used with frequency
switched spectra. Channel contents c
c[i] = (c[i] - c[i+j])/2where
j is the number of channels corresponding to the frequency
throw. The throw may be both positive or negative. Its value is
normally taken from the scan header but may be given via the throw
option. If both a header value and a value specified via the runstring
are given, the latter overrides the first.
The spectrum header may contain frequency and velocity information
refering to half way between the siganl and reference frequency. The
shift option allows you to correct for this.
example: fold frequency switched spectrum (throw $=$ 20.0 MHz)
fold -throw 20
needs:
use: gauss
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval -ampl amplitude guess amplitude of gaussian -centre centre guess centre of gaussian -width width guess width of gaussian
description: Fit a Gaussian profile to the scan data in showfit.
GAUSS: nnnn offx offy amplitude centre width area
where nnnn is the scan number, offx and offy are the
map offsets in arcmin for the scan.
The area $a$ of the integrated profile is calculated from the
fitted amplitude $A$ and width $Delta x$ according to $a = 1.06times A
times Delta x$.
example: fit profile over velocity range $-5ldots+5$,km/s with guessed amplitude =7.0,K, centre =3.0,km/s and width =1.0,km/s
gauss -vel -5 5 -ampl 7.0 -centre 3.0 -width 1.0
needs:
see also: showfit
use: get
parameters:
scan scan number
options:
-help produce help message -file filename specify full file name
description: This command reads a scan into memory which had
been stored in get will read the first file in the current directory which fits
a file mask of '*.nnnn', where nnnn is the (up to four
digit) scan number. The complete file name may be specified via the
-file option, which also allows retrieval of scans from other
directories.
example: get one scan via scan number and the second one via its full name. The latter one resides in the parent directory.
get 1000 get -file ../HH56.0980
needs:
see also: put , getfits , putfits , getsest
use: getdrsp filename}
parameters:
filename name of data file to read from
options:
-help produce help message -file filename specify full file name -scan n specify number of scan to read -record r specify number of record to read
description: Extract a scan from a
example: extract second scan from file MYDATA.DAT
getdrsp -file MYDATA.DAT -record 2
needs:
see also: putdrsp
use: getfits scan
parameters:
scan file name without extension
options:
-help produce help message -file filename specify full file name
description: Read a scan in SEST/IRAM compatible FITS format.
Unless the -file option is used, the file name is assumed
to have extension .fits. The environment variable $FITSREAD
is checked, and if set, will be prepended to all file names. This
allows access to FITS files in different directories.
Because getfits expects FITS files on disk (one scan per file)
you may have to copy scans from tape to disk first, if your data are
currently on tape. You may use the UNIX command dd to do that.
After mounting your tape (the way to do that will be site dependant)
you may use
dd if=/dev/rmt/0mn ibs=2880 of=scan.fits
which will read the next file from device /dev/rmt/0mn
(which is the DAT tape on a HP-UX work station) with a blocking
factor of 2880 bytes (suitable for FITS) and store the bytes up to
the next EOF in file scan.fits.
example: read file 7000s.fits stored in directory
/news/sessions/yellow/ and convert to
setenv FITSAREA /news/sessions/yellow/ getfits 7000s put
needs:
use: getsest
parameters: none
options:
-help produce help message -file filename specify full file name
description: SEST data in their original, binary format may
be read into =SSSSPPPPNNNN.SPE, where SSSS
are the first four characters of the source name, PPPP are the
four characters of the project designator and NNNN is a four
digit scan number.
example: convert all SEST scans following the above mentioned
naming convention to
foreach scan (=*.*) getsest -file $scan put end
needs:
see also: get , put , getfits , putfits
use: hardcopy
parameters: none
options:
-help produce help message
description: Produce a hardcopy of the current contents of
drpwindow on the system printer.
needs:
use: header
parameters: none
options:
-help produce help message -long produce long form of header
description: Display header information for the scan currently in -long).
The listing of the header information is directed to your terminal by
default, but may be redirected to a file or printer using I/O
redirection. The short form consists of the following information:
nnnn sourcename longitude latitude offx offy freq Tsys time
where
nnnn scan number sourcename first eight characters of source name longitude descriptive longitude of source latitude descriptive latitude of source offx offset in longitude (arcsec) offy offset in latitude (arcsec) freq rest frequency of center channel (MHz) Tsys system temperature (K) time integration time (s)
A listing of 1--line header information for a number of
scans and of the same format as described here may be obtained with the
log command.
example: produce long header of current scan, append to file
orion.head
header -long >>orion.header
needs:
see also: list
use: inquire
parameters: none
options:
-help produce help message
description: Allows you to use the mouse to retrieve x and y
coordinates of points in your current plot (scans or maps). Click with
the left mouse button at any point in drpwindow. The x and y
(world) coordinates will be written to your shell window (i.e. where
you started inquire). Pressing any other mouse button will
terminate the program.
The selected points will be marked by blue crosses in drpwindow,
but will not appear in a hardcopy.
example: use inquire as a digitizer, save data to a file
called position.dat. You will get tab separated x and y coordinates
for all points you clicked at.
inquire > position.dat ( start clicking with left mouse button inside drpwindow ) ( any other mouse button will terminate )
The following script (supplied with basefit uses
inquire for interactive fitting of baselines:
#!/bin/csh -f
#
# interactive fitting of baseline
#
echo 'enter baseline order:'
set order = $<
#
echo 'mark baseline regions with left mouse button'
echo '(any other mouse button to exit):'
#
# run inquire, save output on variable 'limits'
set limits = `inquire`
#
# check that number of points is even
@ count = ( $#limits % 2 )
if $count == 0 then
set count = 1
set base = ( -order $order )
while ($count < $#limits)
# we need strings like '-vel x1 x2'
# every other point is x-coordinate
set base = ( $base '-vel' )
set base = ( $base $limits[$count] )
@ count = ( $count + 2)
set base = ( $base $limits[$count] )
@ count = ( $count + 2)
end
baseline $base
showfit
else
echo 'even number of points required'
endif
use: list filename(s)}
parameters:
filename(s) name(s) of file(s) to list
options:
-help produce help message
description: Display one line of header information for all scans whose filenames are given as part of the runstring. The listing of the header information is directed to your terminal by default, but may be redirected to a file or printer using I/O redirection. The lines are logged in a format identical to the short format produced by the header command, except that one extra header line describing the contents of each column is produced as the first line of the listing.
example: list all files matching Orion.* to the printer
list Orion.* | lp
You may use the Unix sort facility to sort the output of
list. The following example will sort all scans (files
with file name extensions starting with a digit) by offset
(i.e. numerical sorting by columns 5 and 6 from the output of
list, counting columns from 0 to 9):
list *.[0-9]* | sort -n +5 -6 -n +6 -7 | egrep '^[0-9]'
Piping through egrep suppresses the header lines produced by
list.
needs: none
see also: header
use: mapshow
parameters: none
options:
-help produce help message -key command specify command filter for 'drp.log' file -col n specify column number to map -pen m specify pen (line style) to be used -map what what: cover|scan#|contr|value|shade|spect -start value specify lowest level for contour maps -inc value specify level increments -mark file supply filename for offset positions to be marked -over write over existing plot -smooth draw smooth contours -nodraft use high quality fonts for text
description: The results which were written to file
logfile
by commands moment, gauss and area may be used to
produce coverage maps and/or contour plots. mapshow can retrieve map
spacing and position angle from the scan header. After use of mapshow
the spectral values of
COMMAND: nnnn offx offy column1 column2 column3 ...
where COMMAND indicates which command produced the line, nnnn is
the scan number, offx and offy are the descriptive positional offsets
for the scan and, finally, column$n$ ($n = 1,2,3ldots$) are numerical
results. See the documentation of moment, area and gauss
in order to know how many columns they produce and in what
order.
The -key option tells the program which lines to look for, i.e.
if you specify -key area only lines in the log file produced by
the area
command are considered, any other entries will be ignored. If you don't use
-key all lines will be taken into account.
The col specifies which column of results you are interested in.
The x and y-coordinates of your map will always be the
logged offx and offy entries. The -col option lets you
choose your z-coordinate.
The -map option lets you specify what to plot:
cover produce a coverage map by marking all offset positions found
in
logfile
with a little cross
scan# same as cover, except that positions are labeled with
scan numbers
value same as cover, except that positions are labeled with
the value of your chosen column (see -col)
contr produce a contour plot of the chosen column versus
the logged offsets. The mapshow will check the range of
z-values and pick appropriate contour levels. Alternatively, you may
specify the first level (option -start) and/or the increment
between levels (option inc).
shade produce a grey scale map, each pixel is shaded with
grey colour relative to the minimum and maximum values in the map.
spect plot all spectra belonging to the scan numbers in
logfile
in their respective position of the map. The scan currently
in
Extra positions in your map may be marked by using the -mark option
followed by a filename. This should refer to a file containing
entries of the form
offx offy symbol
where offx, offy are the offsets of the position to be marked
(in arcmin) and symbol is an integer, which is used as an index into
a table of symbols. The most useful of these are shown in the following
table (for a full listing see the documentation of the
1 2 3 4 5 . + * o x
You may use different line patterns on the screen by using the -pen
option. Default is a solid line. This does not affect the line style used for
the map boundaries.
Normally a coordinate frame is drawn prior to the display of the
contour lines or the coverage, but you may also plot over an already
existing frame by using the -over option. This will e.g. allow
you to show contours for several columns in the log file on the same
plot. Different line styles are automatically chosen for different
columns.
When you use mapshow, the header -long to find that out.
If these values are missing, use pixel to fill them in.
The -smooth option lets you chose smoothed contours (fitted B-splines)
instead of the straight lines normally used.
To increase the quality of text on your hardcopy you may use -nodraft
which will use the extended font of the
example: show a coverage map of all entries from the gauss command, mark
each position with the fitted centre velocity (column 3).
mapshow -key gauss -col 3 -map value
produce a contour plot of integrated intensities from the area
command. Contours will be drawn with pen 1. First draw frame and values of
column 1, then draw values of column 2 on top. Contours are drawn in steps
of 0.5, starting with 1.0. Grey scale maps and contour plots may be combined
similarly.
mapshow -key area -col 1 -map contr -start 1.0 -inc 0.5 mapshow -key area -col 2 -map contr -start 1.0 -inc 0.5 -over
needs:
see also: area , gauss , moment , moment pixel
, fitsmap , fitscubeuse: matlab
parameters: none
options:
-file filename specify output filename -vel save velocity as x-axis (default) -freq save frequency as x-axis -chan save channel contents only
description: You may want to export your spectra to the
commercial matlab
command will write the contents of load command (see your scannnnn.mat, where nnnn is the scan number.
Three entities will be saved,
i.e. after loading the data file into
source - a character array holding the name of the source
header - a minimal spectrum header containing an array
(column vector) of (currently) eight numbers, the
order and meaning of which are as follows:
(1) descriptive longitude of scan in degrees
(2) descriptive latitude of scan in degrees
(3) descriptive offset in longitude in degrees
(4) descriptive offset in latitude in degrees
(5) system temperature in K
(6) integration time in s
(7) rest frequency of centre channel in GHz
(8) source velocity of centre channel in km/s
T - If the -vel
or -freq option has been used this will be a n by 2 array
of numbers containing an array of velocities or frequencies
in column 1 and the channel contents as column 2; n is the number of
channels. If the -chan option it will just be a n by 1 array
with channel contents as the only column.
example: write out the current scan in
matlab
then within scan1000.mat):
load scan1000
plot(T(:,1),T(:,2))
title(source) % use the source name as title
xlabel('velocity in km/s')
ylabel('antenna temperature in K')
needs:
use: moment
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval
description: Calculate a number of statistical values between min
and max (or over whole spectra if no option is used).
The results will be expressed in the unit used for the limits and will
be logged to file
logfile
in the following format:
MOMENT: nnnn offx offy int cen ew Tp Tm rms
where nnnn is the scan number, offx and offy are the
descriptive offsets in arcmin for the scan, int is the integrated
intensity, cen is the centroid velocity, frequency or channel, ew
is the equivalent width, Tp and Tm are the peak and mean
temperature for the given range. Centroid and equivalent width are
calculated in the same unit as was used for specifying the range, or
in velocity, if no range was given.
example: calculate moments for velocity range -10 -- 5 km/s. Results will be in K*km/s.
moment -vel -10 5
needs:
see also: area
use: put
parameters: none
options:
-help produce help message
description: The put command saves the scan currently
held by -file option is given, the
file name chosen will follow the
following pattern: sssss.nnnn, where sssss are the alphanumeric
characters of the source name and nnnn is a four digit scan number
(using leading zeroes if necessary). Any other filename can be used
by specifying the -file option. This option would also
allow to store the file under a different directory than your
current directory, which is the default.
example: store scan in $HOME directory as gustaf.m51
put -file $HOME/gustaf.m51
needs:
see also: get , getfits , putfits , getsest
use: putdrsp filename
parameters:
filename name of data file to append to
options:
-help produce help message -file filename specify full file name
description: Write a scan in a format readable by
example: append current scan to file MYDATA.DAT
putdrsp MYDATA.DAT
needs:
see also: getdrsp
use: putfits
parameters: none
options:
-help produce help message -file filename specify full file name
description: Write a scan in SEST/IRAM compatible FITS format.
Unless the -file option is used, the file name will be
nnnndrp.fits where nnnn is the scan number.
The environment variable $FITSREAD
is checked, and if set, will be prepended to all file names. This
allows stroing of FITS files in different directories.
example: write to file ngc1234.fits in directory
/users/guest/fitsdata/.
setenv FITSAREA /users/guest/fitsdata/ putfits -file ngc1234.fits
needs:
use: redres
parameters: none
options:
-help produce help message -factor f specify redressing factor (> 1.0) -vel dv specify new velocity resolution -freq df specify new frequency resolution
description: To change the spectral resolution of the scan
currently in
example: do hanning smoothing followed by a reduction of channels
filter -hanning redres -factor 2.0
needs:
see also: filter
use: reverse
parameters: none
options:
-help produce help message
description: This command will reverse the spectrum currently
hold in
needs:
use: scale value}
parameters:
value the value by which to multiply all channels
options:
-help produce help message
description: All channels of the scan
currently held by
example: invert the temperature scale, i.e. multiply all channels by $-1.0$
scale -1.0
needs:
see also: bias
use: show
parameters: none
options:
-help produce help message -vel min max choose velocity interval -freq min max choose frequency interval -chan min max choose channel interval -temp min max choose intensity range -histo show as histogram -over don't erase existing plot -zero draw $y = 0.0$ line -noframe don't draw a coordinate frame -nodraft use high quality fonts for text -rel label x-axis relative to centre channel -grid draw grid at major tick intervals
description: display the scan hold by drpwindow (which will have to exist). The range for both x-
and y-axis may be given, where the unit for the x-region is
selectable. The x-axis will be labelled accordingly. In particular
with a frequency axis, it might be preferable to have the x-axis
labelled with frequency relative to the rest frequency of the
header: use the -rel option to achive this. (This will
actually work with a velocity or channel axis as well.)
You may plot several spectra on top of each other by specifying the
-over option with all but the first scan. You may use the
-noframe and -grid options to alter the default axis
system drawn.
To obtain the highest quality for a later hardcopy use the -nodraft
option, which will draw all labels with the extended font of
the drpwindow).
example: show scan over velocity range -2.0 to 8.0 km/s
show -vel -2.0 8.0
show scan, do not erase screen before plotting, show temperature
range -1.0 to 4.0 K, use frequency as x-axis (note that two '0's
are needed as place holders after -freq, the whole range
will be plotted):
show -over -temp -1.0 4.0 -freq 0 0
needs:
see also: showfit
use: showfit
parameters: none
options:
-help produce help message
description: showfit allows you to display fit results
from e.g. baseline or gauss commands on top
of a currently displayed spectrum.
The showfit command may only be used after a
spectrum has been plotted on
the graphics screen, i.e. showfit has to be preceeded by the
show command. There may be commands in between the two if they
leave the showfit
gets the screen scaling information from show through
example: show scan, fit gaussian profile and show fit results
show; gauss; showfit
needs:
see also: show , baseline , gauss
use: subtract
parameters: none
options:
-help produce help message
description: The scan currently held by
example: fit gaussian profile, subtract and look at residuals
gauss; subtract; show
needs:
see also: baseline , gauss , showfit
use: swap
parameters: none
options:
-help produce help message
description: The swap command exchanges the
contents of the
needs:
use: tcopy
parameters: none
options:
-help produce help message
description: The scan currently held by temp). Could be used when
you want to store the spectrum temporarily.
needs:
see also: swap , temp , subtract
use: temp
parameters: none
options:
-help produce help message
description: The scan currently held by baseline or gauss.
needs:
see also: swap , tcopy , subtract
use: zero
parameters: none
options:
-help produce help message
description: Clear the
example: zero accumulator and start adding spectra
zero get 1000; accum get 1001; accum get 1002; accum average
needs:
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