AIPS NRAO AIPS HELP file for HLPXGAUS in 31DEC24



As of Tue Nov 12 9:43:19 2024


HLPXGAUS Run-time help for task XGAUS

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EXIT
This option causes the interactive portion of XGAUS to finish.  The
task then resumes, AIPS, releases the TV device, and, if DOOUTPUT is
greater than zero, writes the output cataloged images.  The residual is
written if DOOUTPUT = 1 or 3 and the parameter images are written if
DOOUTPUT = 2 or 3.
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SET MIN S/N
This option allows you to specify the minimum signal to noise ratio in
absolute value of amplitude for acceptable solutions.  One ratio for
each of the NGAUSS components will be used.  The REDO ALL and FLAG ALL
operations use this value to test whether a solution should be redone
or flagged, resp.  A value of 0 or less will cause the test for the
specific Gaussian component to be ignored.  The current values of these
parameters are displayed above the menu.  You may enter fewer than
NGAUSS values, in which case the first value will be substituted for
those that you did not enter.  This may be okay.
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SET MAX RES
This option allows you to specify the maximum residual for acceptable
solutions.  You will be prompted in the terminal window to enter one
value in the units of the input image.  The REDO ALL and FLAG ALL
operations use this value to test whether a solution should be redone
or flagged, resp.  A value of 0 or less will cause the test for peak
residual to be ignored.  The current value of this parameter is
displayed above the menu.
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SET CENTER RANGE
This option allows you to specify the minimum and maximum offset from
the reference pixel for the centers in acceptable solutions.  One range
for each of the NGAUSS components will be used.  Units are pixels.
The REDO ALL and FLAG ALL operations use these values to test whether a
solution should be redone or flagged, resp.  When the maximum is less
than or equal the minimum the test on component center for the specific
Gaussian component is ignored.  The current values of these parameters
are displayed above the menu.  You may enter fewer than 2 * NGAUSS
values.  The values for the first Gaussian are used for the values you
did not enter.  This is probably a bad idea.
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SET PEAK RANGE
This option allows you to specify the minimum and maximum peak value for
the Gaussians in acceptable solutions.  One range for each of the NGAUSS
components will be used.  Units are Jy/beam. The REDO ALL and FLAG ALL
operations use these values to test whether a solution should be redone
or flagged, resp.  When the maximum is less than or equal the minimum
the test on component peak for the specific Gaussian component is
ignored.  The current values of these parametersare are displayed above
the menu.  You may enter fewer than 2 * NGAUSS values.  In that case,
the values entered for the first Gaussian are used for the values you
did not enter.  This may not be a good idea.
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SET WIDTH RANGE
This option allows you to specify the minimum and maximum width (FWHM)
for the components in acceptable solutions.  One range for each of the
NGAUSS components will be used.  Units are pixels.  The REDO ALL and
FLAG ALL operations use these values to test whether a solution should
be redone or flagged, resp.  When the maximum is less than or equal
the minimum the test on component width for the specific Gaussian
component is ignored.  The current values of these parameters are
displayed above the menu.  You may enter fewer than 2 * NGAUSS values.
In this case, the values entered for the first Gaussian are used for
the values that you did not enter.  This may not be a good idea.
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SET MAX ERR WID
This option allows you to specify the maximum uncertainty in component
width for acceptable solutions.  One maximum for each of the NGAUSS
components will be used.  The REDO ALL and FLAG ALL operations use this
value to test whether a solution should be redone or flagged, resp.  A
value of 0 or less will cause the test for the specific Gaussian
component to be ignored.  The current values of these parameters are
displayed above the menu.  You may enter fewer than NGAUSS values.  In
that case, the value entered for the first Gaussian will be used for the
values you did not enter.  This may be okay.
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REDO ALL
This option allows you to try to improve selected solutions.  The
operation examines all pixels for which there is a solution.  If (1)
the absolute value of signal-to-noise ratio in amplitude in any
component is below the minimum for that component, (2) the peak value
of any component is outside the range of peak values for that component,
(3) the center pixel in any component is outside the range of central
pixels for that component, (4) the width of any component is outside
the range of widths for that component, (5) the uncertainty in the width
of any component is greater than the maximum for that component, or (6)
the peak residual after the fit components are subtracted is greater
than the maximum residual, the solution for that row of the input image
is done over.  TV control of the initial guess is allowed even for
single Gaussian fits in the hope of forcing a better solution.
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FLAG ALL
This option allows you to flag selected solutions.  The operation
examines all pixels for which there is a solution.  If (1) the absolute
value of signal-to-noise ratio in amplitude in any component is below
the minimum for that component, (2) the peak value of any component is
outside the range of peak values for that component, (3) the center
pixel in any component is outside the range of central pixels for that
component, (4) the width of any component is outside the range of
widths for that component, (5) the uncertainty in the width of any
component is greater than the maximum for that component, or (6) the
peak residual after the fit components are subtracted is greater than
the maximum residual, the solution for that row of the input image is
marked as failed.
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OFF ZOOM
This option in the main menu allows you to turn off the zoom function
selected with TVZOOM in the image display menu.
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OFF TRANSFER
This option in the main menu turns of any black-and-white enhancements
done by TVTRANSF and any coloring done by TVPSEUDO or TVPHLAME in the
image display menu.
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SET DOOUTPUT
The option cycles the value of the DOOUTPUT adverb from 0 through 3
and back to 0.  The value of DOOUTPUT, displayed at the top of the TV
screen, when the EXIT option is selected determines whether the residual
image is written to disk (DOOUTPUT = 1 or 3) and whether the parameter
images are written to disk (DOOUTPUT = 2 or 3).
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ADD TO LIST
This option prompts you in the terminal window to enter 2 integers which
specify the X, Y pixel coordinates in the output image of a pixel for
which you would like to revisit the fit.  You can prepare a list of
pixels for revisiting using this option or CURVALUE in the image display
menu.  You can list these pixels (SHOW LIST) and you can the repeat the
fitting of them with REDO LIST or simply flag them out with FLAG LIST.
If you want to remove a pixel from the list, enter its pixel coordinates
with negative signs.  Note that the list may include pixels for which
there is not currently a solution.
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SHOW LIST
This option displays in the message window the current list of output
image pixels which will be revisited with the REDO LIST and FLAG LIST
options.  ADD TO LIST may be used to add a pixel to or remove a pixel
from this list.
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REDO LIST
The output image pixels in the current list are revisited to see if it
is possible to improve upon the current solutions (if any).  The usual
options to mark BAD, to REDO, to QUIT, and to turn off the TV
interaction are all offered.  The list is processed in inverse order
and its length reduced as one goes.  Thus a QUIT in the middle will
leave the first part of the list untouched.  Note that turning off the
TV will eliminate any chance to enter better guesses to force a better
fit.
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FLAG LIST
The output pixels in the current list are revisited in the solutions
table and those solutions are marked as failed.  The list is reset
after this operation.
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SWAP LIST 1-
This option allows you to swap the solutions for Gaussian component 1
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 2-
This option allows you to swap the solutions for Gaussian component 2
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 3-
This option allows you to swap the solutions for Gaussian component 3
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 4-
This option allows you to swap the solutions for Gaussian component 4
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 5-
This option allows you to swap the solutions for Gaussian component 5
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 6-
This option allows you to swap the solutions for Gaussian component 6
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SWAP LIST 7-
This option allows you to swap the solutions for Gaussian component 7
with those of Gaussian component  at all of the pixels in the list.
The list is reset after this operation.
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SHOW IMAGE A
These options allow you to enter an image display mode while displaying
an image of the peak value of Gaussian component .  The value range
in the image is displayed on the message terminal in input image units.
The image display mode offers a menu including OFF TRANSF, OFF COLOR,
TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are
the familiar operations except that CURVALUE allows you to add to a
pixel list for later re-examination of the solutions.  You can also
choose to re-load the image to the TV with a selection of transfer
functions.
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SHOW IMAGE EA
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the  peak value of Gaussian component
.  The value range in the image is displayed on the message terminal
in input image units.  The image display mode offers a menu including
OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE,
and RETURN.  All are the familiar operations except that CURVALUE
allows you to add to a pixel list for later re-examination of the
solutions.  You can also choose to re-load the image to the TV with a
selection of transfer functions.
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SHOW IMAGE C
These options allow you to enter an image display mode while displaying
an image of the position of Gaussian component  with respect to the
X axis reference pixel.  The value range in the image is displayed on
the message terminal in X-axis pixels.  The image display mode offers
a menu including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME,
TVZOOM, CURVALUE, and RETURN.  All are the familiar operations except
that CURVALUE allows you to add to a pixel list for later
re-examination of the solutions.  You can also choose to re-load the
image to the TV with a selection of transfer functions.
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SHOW IMAGE EC
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the position of Gaussian component 
with respect to the X axis reference pixel.  The value range in the
image is displayed on the message terminal in X-axis pixels.  The
image display mode offers a menu including OFF TRANSF, OFF COLOR,
TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the
familiar operations except that CURVALUE allows you to add to a pixel
list for later re-examination of the solutions.  You can also choose to
re-load the image to the TV with a selection of transfer functions.
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SHOW IMAGE W
These options allow you to enter an image display mode while displaying
an image of the width of Gaussian component .  The value range in the
image is displayed on the message terminal in X-axis pixels.  The image
display mode offers a menu including OFF TRANSF, OFF COLOR, TVTRANSF,
TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the familiar
operations except that CURVALUE allows you to add to a pixel list for
later re-examination of the solutions.  You can also choose to re-load
the image to the TV with a selection of transfer functions.
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SHOW IMAGE F
These options allow you to enter an image display mode while displaying
an image of the "flux" (peak times width) of Gaussian component .
The value range in the image is displayed on the message terminal in
image units times X-axis pixels.  The image display mode offers a menu
including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM,
CURVALUE, and RETURN.  All are the familiar operations except that
CURVALUE allows you to add to a pixel list for later re-examination of
the solutions.  You can also choose to re-load the image to the TV with
a selection of transfer functions.
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SHOW IMAGE EW
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the width of Gaussian component .  The
value range in the image is displayed on the message terminal in X-axis
pixels.  The image display mode offers a menu including OFF TRANSF,
OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.
All are the familiar operations except that CURVALUE allows you to add
to a pixel list for later re-examination of the solutions.  You can also
choose to re-load the image to the TV with a selection of transfer
functions.
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SHOW IMAGE EF
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the "flux" (peak times width) of Gaussian
component .  The value range in the image is displayed on the message
terminal in image units times X-axis pixels.  The image display mode
offers a menu including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO,
TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the familiar operations
except that CURVALUE allows you to add to a pixel list for later
re-examination of the solutions.  You can also choose to re-load the
image to the TV with a selection of transfer functions.
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IMAGE A
These options allow you to enter an image display mode while displaying
an image of the peak value of Gaussian component .  The value range
in the image is displayed on the message terminal in input image units.
The image display mode offers a menu including OFF TRANSF, OFF COLOR,
TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are
the familiar operations except that CURVALUE allows you to add to a
pixel list for later re-examination of the solutions.  You can also
choose to re-load the image to the TV with a selection of transfer
functions.
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IMAGE EA
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the peak value of Gaussian component .
The value range in the image is displayed on the message terminal in
input image units.  The image display mode offers a menu including
OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE,
and RETURN.  All are the familiar operations except that CURVALUE
allows you to add to a pixel list for later re-examination of the
solutions.  You can also choose to re-load the image to the TV with a
selection of transfer functions.
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IMAGE C
These options allow you to enter an image display mode while displaying
an image of the position of Gaussian component  with respect to the
X axis reference pixel.  The value range in the image is displayed on
the message terminal in X-axis pixels.  The image display mode offers
a menu including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME,
TVZOOM, CURVALUE, and RETURN.  All are the familiar operations except
that CURVALUE allows you to add to a pixel list for later
re-examination of the solutions.  You can also choose to re-load the
image to the TV with a selection of transfer functions.
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IMAGE EC
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the position of Gaussian component 
with respect to the X axis reference pixel.  The value range in the
image is displayed on the message terminal in X-axis pixels.  The
image display mode offers a menu including OFF TRANSF, OFF COLOR,
TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the
familiar operations except that CURVALUE allows you to add to a pixel
list for later re-examination of the solutions.  You can also choose to
re-load the image to the TV with a selection of transfer functions.
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IMAGE W
These options allow you to enter an image display mode while displaying
an image of the width of Gaussian component .  The value range in the
image is displayed on the message terminal in X-axis pixels.  The image
display mode offers a menu including OFF TRANSF, OFF COLOR, TVTRANSF,
TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the familiar
operations except that CURVALUE allows you to add to a pixel list for
later re-examination of the solutions.  You can also choose to re-load
the image to the TV with a selection of transfer functions.
C-----------------------------------------------------------------------
IMAGE F
These options allow you to enter an image display mode while displaying
an image of the "flux" (peak times width) of Gaussian component .
The value range in the image is displayed on the message terminal in
image units times X-axis pixels.  The image display mode offers a menu
including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM,
CURVALUE, and RETURN.  All are the familiar operations except that
CURVALUE allows you to add to a pixel list for later re-examination of
the solutions.  You can also choose to re-load the image to the TV with
a selection of transfer functions.
C-----------------------------------------------------------------------
IMAGE EW
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the width of Gaussian component .  The
value range in the image is displayed on the message terminal in X-axis
pixels.  The image display mode offers a menu including OFF TRANSF,
OFF COLOR, TVTRANSF, TVPSEUDO, TVPHLAME, TVZOOM, CURVALUE, and RETURN.
All are the familiar operations except that CURVALUE allows you to add
to a pixel list for later re-examination of the solutions.  You can also
choose to re-load the image to the TV with a selection of transfer
functions.
C-----------------------------------------------------------------------
IMAGE EF
These options allow you to enter an image display mode while displaying
an image of the uncertainty in the "flux" (peak times width) of Gaussian
component .  The value range in the image is displayed on the message
terminal in image units times X-axis pixels.  The image display mode
offers a menu including OFF TRANSF, OFF COLOR, TVTRANSF, TVPSEUDO,
TVPHLAME, TVZOOM, CURVALUE, and RETURN.  All are the familiar operations
except that CURVALUE allows you to add to a pixel list for later
re-examination of the solutions.  You can also choose to re-load the
image to the TV with a selection of transfer functions.
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RETURN
This option returns from the image display menu to the primary menu to
select a different image to display, to set data selection values, and
to revisit selected solutions in order to modify or flag them.
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LOAD AS LN
This option re-loads the current image using a linear transfer function
from the image minimum to its maximum.  The image you are now viewing
was loaded with the L2 (extreme log) transfer function.
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LOAD AS SQ
This option re-loads the current image using a square root transfer
function from the image minimum to its maximum.  The image you are now
viewing was loaded with the LN (linear) transfer function.
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LOAD AS LG
This option re-loads the current image using a logarithmic transfer
function from the image minimum to its maximum.  The image you are now
viewing was loaded with the SQ (square root) transfer function.
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LOAD AS L2
This option re-loads the current image using a more extreme logarithmic
transfer function from the image minimum to its maximum.  The image you
are now viewing was loaded with the LG (logarithmic) transfer function.
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SET WINDOW
This option turns on a standard TVWINDOW operation to set the lower left
corner and upper right corner of a sub-image that you would like to view
in more detail.  Buttons A and B switch between corners and buttons C
and D set the desired window which is immediately displayed.
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RESET WINDOW
This option returns the image display to the full image.  This option is
available in the edit screen and the image display screen.
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LABEL WEDGE?
Turns on or off the labeling of the step wedge plotted at the bottom
of each image.
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OFF TRANSF
This option turns off any black-and-white enhancements done in TVTRANSF.
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OFF COLOR
This option turns of any color enhancements done in TVPSEUDO or
TVPHLAME.  It has no effect if the image is in black and white.
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TVTRANSF
This option allows you to set the black-and-white transfer function
using the TV cursor to control intercept and slope.  Buttons A and B
turn a plot of the LUT on and off, button C reverses the sign of the
slope, and button D ends the enhancement and returns to the menu.
Instructions appear on the message screen.
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TVPSEUDO
This option allows you to set the color transfer function using the TV
cursor.  Button A loops through all possible RGB triangles, button B
selects a circle in hue (which is very useful for phase displays),
button C selects several color contours, and button D ends the
enhancement and returns to the menu.  As in AIPS, the TV cursor is used
to adjust the colors within the selected function.  Instructions appear
on the message screen.
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TVPHLAME
This option allows you to set the color transfer function using the TV
cursor and a flame-like color scheme.  Buttons A and B cycle through the
sequence of all possible color combinations, while buttons C and D end
the enhancement and return to the menu.  The TV cursor X position
adjusts the image intensity at which the color turns more white, while
the Y position adjusts the way colors add (the gamma).  Instructions
appear on the message screen.
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TVZOOM
This option lets you set the TV zoom magnification factor and to set the
point about which the zoom takes place.  The cursor points at the zoom
center which will be shifted to the center of the screen.  A hit on
buttons A or B increments the magnification factor and on button C
decrements the magnification factor in a circular fashion.  Hit button D
to exit.  Instructions appear on the message screen.
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CURVALUE
To perform an interactive display of the pixel locations and values of
the image visible on the TV.  The X and Y pixel coordinates, the pixel
value, and the units of the pixel value are displayed in TV graphics
channel 1 at the upper left of the display.  The cursor position
determines which pixel is shown.  Unlike other CURVALUEs in AIPS,
buttons A and B allow you to add the selected pixel to a list of pixels
to be flagged or re-fit at a later time.  Buttons C and D end the
display and return to the menu.  Instructions appear on the message
screen.  The pixel values are read from the image in memory and hence
preserve accuracy.
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SWAP 1-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 1 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
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SWAP 2-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 2 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
SWAP 3-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 3 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
SWAP 4-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 4 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
SWAP 5-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 5 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
SWAP 6-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 6 with that of Gaussian component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
SWAP 7-
This option allows you to select polygonal regions for which you wish to
swap the solution for component 7 with that of component .
The interactive polygon setting operation starts in the "set polygon n"
mode where button A selects a vertex in the polygon, B sets the last
vertex in the polygon and gets ready to set polygon n+1, C sets the last
vertex and enters a vertex editing mode, and D sets the last vertex
and exits the polygon setting.  In the vertex editing mode, move the
cursor to a vertex to be moved and press button A or B to reset its
position.  After moving it to the desired point, press button A or B
to fix that point and restart the vertex editing mode.  Press button C
to fix that point and then start creating polygon n+1.  Press button D
to fix that point and exit the polygon setting.  Once button D has
been set, the selected areas of pixels have their solutions swapped.
The images are updated and reloaded automatically.
C-----------------------------------------------------------------------
NEXT WINDOW
Very large images may not be able to fit on your TV.  When the image
exceeds the size of the TV, the top line will show the component
number followed by a subimage number in parentheses and the NEXT
WINDOW option will appear.  The first sub-images displayed is called
number 0 and shows the full image every n'th pixel in X and Y.
Sub-image 1 begins at the lower left, moves right, then back to the
left and up, and so forth until the top right is reached.  Every pixel
is displayed in these sub-images.  Use the NEXT WINDOW option to step
through the sub-images in a circular fashion.
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DO FIT
Selecting this option tells XGAUS to use the current initial guess to
try to fit the model parameters.
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RE-GUESS
Selecting this option tells XGAUS to request the input of a new initial
guess of the model parameters using the TV.  You will be prompted, one
component at a time, to point at the peak position (both Y, the value,
and X, the channel matter) and then the half-power position (only X, the
channel matters).
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BAD
Selecting this option tells XGAUS to mark the current pixel as "bad"
in the model file and then go on to the next pixel.
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QUIT
Selecting this option causes XGAUS to exit cleanly.  It may be
re-started later with the same model file to continue model fitting
and image editing.
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GOOD
Selecting this option tells XGAUS that the fit appears to be good.
The task stores the parameters in the model file and goes on to the
next pixel.
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TVOFF
Selecting this option turns off the TV interaction and tells XGAUS to
ncontinue fitting with its own self-generated initial guesses.  The
interactive mode will be turned back on when the fit parameters are
outside a reasonable range of values, the RMS exceeds RMSLIMIT, or when
XGAUS reaches the image editing stage.
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HAND
Selecting this options tells the task that you wish to enter an initial
guess by typing in values in the AIPS terminal window (after prompting).
In XGAUS, the parameters are the component peak value (Jy/beam usually),
component center in pixels wrt reference pixel, the full width at half
maximum, and 3 flags to control whether these values may be fit or are
held constant.  Flag values <= 0 => hold the parameter fixed and omitted
flags are taken as 1 (fit the parameter).  This fixing of the value
applies only to any fit of the current spectrum using the hand-entered
values.
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Selecting this option tells XGAUS to try the fitting again using only
 Gaussians.
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AIPS