imexamine [input [frame]]
input
Optional list of images to be examined. If specified, images are examined
in turn, displaying them automatically. If no images are specified the
images currently loaded into the image display are examined.
frame = 1
During program execution, a query parameter specifiying the frame to be loaded.
May also be specified on the command line when imexamine is used as a
task to display a new image, to specify the frame to be loaded.
image
Query parameter for selecting images to be loaded.
logfile =
Logfile filename in which to record output of the commands producing text.
If no filename is given then no logfile will be kept.
keeplog = no
Log output results initially? Logging can be toggled interactively during
program execution.
defkey = a
Default key for cursor x-y input list. This key is applied to input
cursor lists which do not have a cursor key specified. It is used
to repetitively apply a cursor command to a list of positions typically
obtained from another task.
autoredraw = yes
Automatically redraw graphs after a parameter change? If no then graphs
are only drawn when a graph or redraw command is given.
If yes then colon commands which modify a parameter of the last graph
will automatically redraw the graph. A common example of this would
be changing the graph limits.
allframes = yes
Use all frames for displaying images? If set, images from the input list
are loaded cycling through the available frames. If not set the last frame
loaded is reused.
nframes = 0
Number of display frames. When automatically loading images from the input
list only this number of frames will be used. This should, of course,
not exceed the number of frames provided by the display device.
If the number of frames is set to 0 then the task will query the display
device to determine how many frames are currently allocated. New frames may
be allocated during program execution by displaying images with the 'd' key.
ncstat = 5, nlstat = 5
The statistics command computes values from a box centered on the
specified cursor position with the number of columns and lines
given by these parameters.
graphcur =
Graphics cursor input. If null the standard graphics cursor is used whenever
graphics cursor input is requested. A cursor file in the appropriate
format may be substituted by specifying the name of the file.
imagecur =
Image display cursor input. If null the standard image display cursor is
used whenever image cursor input is requested. A cursor file in the
appropriate format may be substituted by specifying the name of the file.
Also the image cursor may be changed to query the graphics device or
the terminal by setting the environment parameter "stdimcur"
to "stdgraph" or "text" respectively.
wcs = logical
The world coordinate system (wcs) to be used for axis labeling when
input is from images.
The following standard world systems are predefined.
logical
Logical coordinates are image pixel coordinates relative to the image currently
being displayed.
physical
The physical coordinate system is invariant with respect to linear
transformations of the physical image matrix. For example, if the reference
image was created by extracting a section of another image, the physical
coordinates of an object in the reference image will be the pixel coordinates
of the same object in the original image. The physical coordinate system
thus provides a consistent coordinate system (a given object always has the
same coordinates) for all images, regardless of whether any user world
coordinate systems have been defined.
world
The "world" coordinate system is the current default WCS.
The default world system is the system named by the environment variable
defwcs if defined in the user environment and present in the reference
image WCS description, else it is the first user WCS defined for the image
(if any), else physical coordinates are returned.
xformat = wcsformat , yformat =
The numerical format for the world coordinate labels in the line and column
plots and the format for printing world coordinates. The values may be ""
(an empty string), %f for decimal format, %h and %H for xx:xx:xx format, and
%m and %M for xx:xx.x format. The upper case %H and %M convert degrees
to hours. Images sometimes include recommended coordinate formats as
WCS attributes. These are used if the format specified by these parameters
is "". Any other value will override the image attribute.
In addition to these three reserved WCS names, the name of any user WCS defined for the reference image may be given. A user world coordinate system may be any linear or nonlinear world system.
graphics = stdgraph
Graphics output device. Normally this is the standard graphics device
specified by the environment variable "stdgraph".
display = display(image='$1',frame=$2)
Command template used to display an image. The image to be displayed is
substituted for argument $1 and the frame for argument $2. Any display task
may be used for image display by modifying this template.
use_display = yes
Use the image display? Set to no to disable all interaction with the
display device, e.g., when working at a terminal that does not provide image
display capabilities.
The various graphs and the aperture sum command have parameters defined in additional parameter sets. The parameter sets are hidden tasks with the first character being the cursor command graph key that uses the parameters followed by "imexam". The parameter sets are:
cimexam Parameters for column plots
eimexam Parameters for contour plots
himexam Parameters for histogram plots
jimexam Parameters for line 1D gaussian fit plots
kimexam Parameters for column 1D gaussian fit plots
limexam Parameters for line plots
rimexam Parameters for radial profile plots and aperture sums
simexam Parameters for surface plots
vimexam Parameters for vector plots (centered and endpoint)
The same parameters dealing with graph formats occur in many of the parameter sets while some are specific only to one parameter set. In the summary below those common to more than one parameter set are shown only once. The characters in parenthesis are the graph key prefixes for the paraemter sets in which the parameter occurs.
angh = -33., angv = 25. (s)
Horizontal and vertical viewing angles (degrees) for surface plots.
autoscale = yes (h)
In the case of integer data, automatically adjust nbins and
z2 to avoid aliasing effects.
axes = yes (s)
Draw axes along edge of surface plots?
background = yes (jkr)
Fit and subtract a background for aperture sums, 1D gaussian fits, and
radial profile plots?
banner = yes (cehjklrsv)
Add a standard banner to a graph? The standard banner includes the
IRAF user and host identification and time, the image name and title,
and graph specific parameters.
boundary = constant (v)
Boundary extension for vector plots in which the averaging width might
go outside of the image.
box = yes (cehjklrv)
Draw graph box and axes?
buffer = 1. (r)
Buffer distance from object aperture of background annulus for aperture sums
and radial profile plots.
ceiling = INDEF (es)
Ceiling data value for contour and surface plots. A value of INDEF does
not apply a ceiling. (In contour plots a value of 0. also does not
apply a ceiling.)
center = yes (jkr)
Apply a centering algorithm for doing aperture sums, 1D guassian fits,
and radial profile plots?
constant = 0. (v)
Boundary extension constant for vector plots in which the averaging width
might go outside of the image.
dashpat = 528 (e)
Dash pattern for negative contours.
fill = no (e)
Fill the output viewport regardless of the device aspect ratio?
fitplot = yes (r)
Overplot the gaussian fit on the radial profile data?
floor = INDEF (es)
Floor data value for contour and surface plots. A value of INDEF does
not apply a floor. (In contour plots a value of 0. also does not
apply a floor.)
interval = 0 (e)
Contour interval. If 0, a contour interval is chosen which places 20 to 30
contours spanning the intensity range of the image.
label= no (e)
Label the major contours in the contour plot?
logx = no, logy = no (chjklrv)
Plot the x or y axis logarithmically? The default for histogram plots is
to plot the y axis logarithmically.
magzero = 30. (r)
Magnitude zero point for aperture sums.
majrx=5, minrx=5, majry=5, minry=5 (cehjklrv)
Maximum number of major tick marks on each axis and number of minor tick marks
between major tick marks.
marker = box (chjklrv)
Marker to be drawn if pointmode = yes. Markers are "point", "box",
"cross", "plus", "circle", "hebar", "vebar", "hline", "vline" or "diamond".
naverage = 1 (cjklv)
Number of lines, columns, or width perpendicular to a vector to be averaged.
nbins = 512 (h)
The number of bins in, or resolution of, histogram plots.
ncolumns = 21, nlines = 21 (ehs)
Number of columns and lines used in contour, histogram, and surface plots.
ncontours = 5 (e)
Number of contours to be drawn. If 0, the contour interval may be specified,
otherwise 20-30 nicely spaced contours are drawn. A maximum of 40 contours
can be drawn.
nhi = -1 (e)
If -1, highs and lows are not marked. If 0, highs and lows are marked
on the plot. If 1, the intensity of each pixel is marked on the plot.
pointmode = no (chlv)
Plot points or marks instead of lines?
pointmode = yes (jkr)
Plot points or marks instead of lines? For radial profile plots point
mode should always be yes.
radius = 5. (r)
Radius of aperture for aperture sums and centering.
round = no (cehjklrv)
Extend the axes up to "nice" values?
rplot = 8. (jkr)
Radius to which the radial profile or 1D gaussian fits are plotted.
sigma = 2. (jk)
Initial guess for 1D gaussian fits. This must be close to the true value
for convergence. Also the four times the initial sigma is used to define
the distance to the background region for the initial background estimate.
szmarker = 1 (chjklrv)
Size of mark (except for points). A positive size less than 1 specifies
a fraction of the device size. Values of 1, 2, 3, and 4 signify
default sizes of increasing size.
ticklabels = yes (cehjklrv)
Label the tick marks?
title = (cehjklrsv)
User title. This is independent of the the standard banner title.
top_closed = no (h)
Include z2 in the top histogram bin? Each bin of the histogram is a
subinterval that is half open at the top. Top_closed decides whether
those pixels with values equal to z2 are to be counted in the histogram. If
top_closed is yes, the top bin will be larger than the other bins.
width = 2. (jkr)
Width of background region for background subtraction in aperture sums,
1D gaussin fits, and radial profile plots.
wcs = physical
World coordinate system for axis labeling and coordinate readback.
x1 = INDEF, x2 = INDEF, y1 = INDEF, y2 = INDEF (chjklrv)
Range of graph along each axis. If INDEF the range is determined from
the data range plus a buffer. The default y1 for histogram plots is 0.
xformat, yformat
Set world image coordinate formats. Any format changes take effect on the next
usage; i.e. there is no automatic redrawing.
xlabel, ylabel (cehjklrv)
Axis labels. Each graph type has an appropriate default. If the label
value is "wcslabel" then the coordinate label from the image WCS
will be used if defined.
xorder = 0 (jk)
Order for 1D gaussian background. If 0 then a median is computed. If
1 then a constant background is fit simultaneously with the other gaussian
parameters. If 2 then a linear background is fit simultaneously with the
other gaussian parameters.
xorder = 0, yorder = 0 (r)
If either parameter is zero then the median value of the
background annulus is used for background subtraction in aperture sums and
radial profile plots. Values greater than zero define polynomial
surface orders for background subtraction. The orders are actually the
number of polynomial terms. An order of 1 is a constant an order of 2
is a plane.
zero = 0. (e)
Greyscale value of the zero contour, i.e., the value of a zero point shift
to be applied to the image data before plotting. Does not affect the values
of the floor and ceiling parameters.
z1 = INDEF, z2 = INDEF (h)
Range of pixel values to be used in histogram. INDEF values default to
the range in the region being histogramed.
Images are examined using an image display, various types of plots, and text output. Commands are given using the image display cursor and/or graphics cursor. This task brings together many of the features of the IRAF image display and graphics facilities with some simple image analysis capabilities.
IMAGE DISPLAY
If use_display is yes the image display is used to examine images. When no input list is specified images may be loaded with the 'd' key, frames selected with 'n', 'p', and ":select", and the scaled contents of the display frame buffer examined if the image itself is not available.
When an input list is specified the 'n', 'p', and ":select" allow moving about the list and new images may be added to the end of the list with 'd'. Images are automatically loaded as they are selected if not currently loaded. Two parameters control how the frames are loaded. The nframes parameter determines which frames are available. Within the available frames images may be loaded by cycling through them if allframes is yes or in the last loaded frame (initially frame 1) if it is no.
When reading the image cursor the frame and the name of the image in the frame are determined. Therefore images may also be selected by changing the frame externally or if the image cursor input is changed from the standard image display to text or file input.
The 'd' command displays an image using the template CL command given by parameter display. Usually this is the standard IRAF tv.display command though in some cirmcumstances other commands like plot.contour may be used. This command may be used to display an image even if use_display is no.
This task is generally intended for interactive use with an image display. However it is possible to disable use of the image display and change the image cursor input to a graphics cursor, a file, or typed in by the user. In this case an input image list is most appropriate but if one is missing, a query will be issued each time a command requiring an image is given.
CURSOR INPUT
Commands are given using cursor input. Generally the image cursor is used to select points in the images to be examined and the key typed selects a particular operation. In addition to the image cursor the graphics cursor is sometimes useful. First, it gives access to the graphics cursor mode commands (see cursors) such as annotating, saving or printing a graph, expanding and roaming, and printing cursor positions. Second, it can give a better perspective on the data for cursor positions than the image cursor. And lastly, it may be needed when an image display is not available. The commands 'g' and 'i' select between the graphics and image cursors. Initially the image cursor is read.
Interpretation of the graph coordinate in terms of an image coordinate depends on the type of graph as described below.
contour plot
This gives image coordinates directly and both the x and y cursor values
are used.
column plot
The x cursor position gives the line coordinate and the column coordinate
used for the plot (that specified before averaging) gives the column
coordinate.
line plot
The x cursor position gives the column coordinate and the line coordinate
used for the plot (that specified before averaging) gives the line
coordinate.
vector plot
The x cursor position defines a column and line coordinate along the vector
plotted.
surface plot
No cursor information is available in this plot and the cursor position
used to make the surface plot (the center of the surface) is used again.
histogram plot
No cursor information is available in this plot and the cursor position
used to make the histogram (the center of the box) is used again.
radial profile plot
No cursor information is available in this plot and the cursor position
used to define the center is used again.
There are some special features associated with cursor input in IRAF which might be useful in some circumstances. The image display cursor can be reset to be a text cursor, graphics cursor, or image cursor by setting the environment variable "stdimcur" to "text", "stdgraph", or "stdimage" respectively. Text cursor input consists of the x and y coordinates, a frame number, and the key or colon command. Another form of text input is to set the value of the cursor input parameter to a file containing cursor commands. There are two special features dealing with text cursor input. If only x and y are entered the default key parameter defkey determines the command. This is particularly useful if one has a list of pixel positions prepared by some other program. The second feature is that for commands not requiring coordinates they may be left out and the command key or colon command entered.
TEXT OUTPUT
The following commands produce text output which may also be appended to a logfile.
a
Circular aperture photometry is performed at the position of the cursor.
If the centering option is selected the cursor position is used as the
initial point for computing the central moments of the marginal distributions
in x and y. The marginal distributions
are obtained from a square aperture with edge dimensions of twice the
aperture radius parameter. Only the pixels above the mean are used in
computing the central moments. If the central moments are in a different
pixel than that used for extracting the marginal distributions the
computation is repeated using the new center.
If the background subtraction option is selected a concentric circular annulus is defined. The inner edge is separated from the object aperture by a specified buffer distance and the outer edge is defined by a width for the annulus. The type of background used is determined by the parameters xorder and yorder. If either parameter is zero then a median of the background annulus is determined. If 1 or greater a polynomial surface of the specified number of terms is fit. Typically the orders are 1 for a constant or 2 for a plane. The median or fitted surface values within the object aperture are then subtracted.
The flux within the circular aperture is computed by simply summing the pixel values with centers within the specified radius of the center position. No partial pixel adjustments are made. If the flux is positive a magnitude is computed as
magnitude = magzero - 2.5 * log10 (flux)
where the magnitude zero point is a user defined parameter.
In addition to the flux, the second intensity momemnts are computed within the aperture. The moments are output as a size, ellipticity, and position angle. The equations defining the moments and related parameters are:
Mxx = sum (x * x * I) / sum (I) Myy = sum (y * y * I) / sum (I) Mxy = sum (x * y * I) / sum (I) r = 2 * sqrt (ln (2) * (Mxx + Myy)) e = sqrt ((Mxx - Myy) ** 2 + (2 * Myy) ** 2) pa = 0.5 * atan (2 * Mxy / (Mxx - Myy))
The size is scaled so that a gaussian intensity distribution gives a value of r equal to the full width at half maximum (FWHM).
Finally, a nonlinear least squares gaussian of fixed center and zero background is fit for a peak intensity and FWHM. Weights which are the inverse square of the pixel radius are used. This has the effect of giving equal weight to all parts of the profile instead of being overwhelmed by the larger number of pixels are larger radii.
The output consists of the x-y coordinates, magnitude, flux, number of pixels within the aperture, mean background, r (FWHM), e, pa (in degrees between -90 and +90 with 0 along the x axis), gaussian peak, and gaussian FWHM. If a quantity is numerically undefined then INDEF is printed.
This aperture photometry tool is intended only for general image analysis and quick look photometry. The background fitting and photometry techniques used are not intended for serious astronomical photometry; other packages, e.g., noao.digiphot.apphot, should be used if precise results are required.
b
The integer pixel coordinates defining a region of the image are printed.
Two cursor positions are used to select sthe range of columns and lines.
The output format consists of the starting and ending column
coordinates and the starting and ending line coordinates. This format is
used as input by some tasks and can be used to generate image sections if
desired.
j, k
The fitted gaussian center, peak, sigma, full width at half maximum, and
background at the center is computed and printed.
m
Statistics of a rectangular region centered on the cursor position are
computed and printed. The size of the statistics box is set by the
parameters ncstat and nlstat. The output format consists
of the image section, the number of pixels, the mean, the median, the
standard deviation, the minimum, and the maximum.
x, y
The cursor x and y coordinates and the pixel value nearest this position
are printed. The 'y' key may be used define a relative origin. If
an origin is defined (is not 0,0) then additional quantities are printed.
These quantities are origin coordinates, the delta x and delta y distances,
the radial distance, and the position angle (in degrees counterclockwise from
the x axis).
z
A 10x10 grid of pixel values is printed. The integer coordinates are
also printed around the grid.
GRAPHICS OUTPUT
The following commands produce graphics output to the specified graphics device (normally the graphics terminal).
c
A plot of a column or average of columns is made with the line number as
the ordinate and the pixel value as the abscissa. The averaging number
and various graph options are specified by the parameters from the
cimexam parameter set.
e
A contour plot of a region centered on the cursor is made. The
size of the region and various contouring and labeling options are
specified by the parameters from the eimexam parameter set.
h
A histogram of a region centered on the cursor is made. The size
of the region and various binning parameters are specified by
the parameters from the himexam parameter set.
l
A plot of a line or average of lines is made with the column number as
the ordinate and the pixel value as the abscissa. The averaging number
and various graph options are specified by the parameters from the
limexam parameter set.
r
A radial profile plot is made. There are options for centering and
background subtraction and aperture sum output is printed as described
for the 'a' aperture sum command.
If the guassian fit parameters are determined and the fitplot
parameter is set the fit
is overplotted. The aperture sum and graph options are specified by the
parameters from the rimexam parameter set.
s
A surface plot of a region centered on the cursor is made. The size
of the region and various surface and labeling options are
specified by the parameters from the simexam parameter set.
u, v
A plot of a vector defined by two cursor positions is made. The 'u'
plot uses the first cursor position to define the center of the vector
and the second position to define the endpoint. The vector is extended
an equal distance in the opposite direction and the graph x coordinates
are the radial distance from the center position. The 'v' plot
uses the two cursor positions as endpoints and the coordinates are
the radial distance from the first cursor position. The vector may
be averaged over a specified number of parallel vectors. The
averaging number and various graph options are specified by the parameters
from the vimexam parameter set.
MISCELLANEOUS COMMANDS
The following commands control useful features of the task.
d
The display command given by the parameter display is given
with appropriate image name. By default this loads the image
display using the tv.display task. When using an input image
list this operation also appends new images to the list for subsequent
'n' and 'p' commands.
f
Redraw the last graph. If the autoredraw parameter is no then
this is used to redraw a graph after making parameter changes with
colon commands. If the parameter is yes then any colon command which
affects the current plot will execute a redraw automatically.
g, i
Cursor input may be selected to be from the graphics cursor (g) or
image display cursor (i).
n, p
Go to the next or previous image in the image list or display frames.
o
Overplot the next graph. This generally only makes sense with the
line, column, and histogram plots.
q
Quit the task.
w
Toggle output to the logfile. If no logfile is specified this has no
effect except to print a message. If the logfile is specified a message
is printed indicating that the logfile has been opened or closed.
Everytime the logfile is opened the current image name and title is
entered as well as when the image is changed. The logfile name may
be set or changed by a colon command.
:select
Select an image. If an input image list is used the specified index
number selects an image from the list. If an input image list is not
used and the image display is used then the specified display frame
is selected. If the new image is different from the previous image
an identification line is inserted in the logfile if it is open.
:eparam, :unlearn
These colon commands manipulate the various parameter sets as
described below.
,> :c<#>, :l<#>
Special colon commands to plot specific columns or lines, symbolically
shown as <#>, rather than use a cusor position.
> :
Special colon command syntax to explicitly give image coordinates for
a cursor command key.
COLON COMMANDS
Sometimes one wants to explicitly enter the coordinates for a command. This may be done with a colon command having the following syntax:
:
where column and line are the coordinates and key is the command.
If the line is not given then
with no space, e.g., ":l64".
Every parameter except the input image list and the display command
may be queried or set by a
colon command. In addition the parameter sets for the various graphs
and aperture sum algorithm may be edited using the eparam editor
and reinitialized to default values using the unlearn command.
There are a large number of parameters as well as many graph types /
parameter sets. To achieve some consistency and order as well as
simplify the colon commands several things have been done.
Many parameters occur in more than one graph type. This includes things
like graph labeling, tickmarks, and so forth. When issuing a colon
command for one of these parameters the current graph type is assumed
to be the one affected. If the graph type is wrong or no graph has
been made then a warning is given.
If the parameter only occurs in one parameter set then the colon command
may be used with any current graph. However, if the parameter affects the
current graph and the automatic redraw option is set then the graph will
be redrawn.
The eparam and unlearn commands also apply by default to the parameters
for the current graph. However, they may take the keystroke character
for the graph as an argument to override this. If the current graph
parameters are changed and the automatic redraw option is set then
the graph will be redrawn.
The important colon commands 'x' and 'y' affect the x1, y1, x2, y2
parameters in most of the graphs. They are frequently used to override
the automatic graph scaling. If no arguments are given the window
limits are set to INDEF resulting in plotting the full range of the
data plus a buffer. If two values are given then only that range of
the data will be plotted.
Explicit image coordinates may be entered using the colon command syntax:
:
where column and line are the image coordinates and the key is one
of the cursor keys. A special syntax for line or column plots is also
available as :c# or :l# where # is a column or line and no space is
allowed.
Other colon commands set or show parameters governing the plots and other
features of the task. Each graph type has it's own set of parameters.
When a parameter applies to more than one graph the current graph is assumed.
If the current graph is not applicable then a warning is given. The
"eparam" and "unlearn" commands may be used to change many parameters and
without an argument the current graph parameters are modified while with
the graph key as an argument the appropriate parameter set is modified.
In the list below the graph key(s) to which a parameter applies are shown.
EXAMPLES
The following example illustrates many of the features in a descriptive
way using the standard image dev$pix.
BUGS
If an operation is interrupted, e.g., an image display or surface plot,
imexamine is terminated rather than the operation in progress.
When used on a workstation imexamine attempts to always position the
cursor to the window (text, image, or graphics) from which input is being
taken. Moving the mouse manually while the program is also trying to move
it can cause the mouse to be positioned to the wrong window, requiring that
it be manually moved to the window from which input is currently being taken.
When entering a colon command in image cursor mode, if one types too fast
the characters typed before the mouse is moved to the input window
will be lost. To avoid this, pause a moment after typing the colon, before
entering the command, and verify that the mouse has been moved to the correct
window. In the future colon command input will be entered without moving
the mouse out of the image window, which will avoid the problem.
cursors,
eparam,
unlearn,
plot.,
tvmark,
digiphot.,
apphot.,
,
implot,
splot,
imedit,
radplt,
imcntr,
imhistogram,
imstatistics,
display,
:c
COMMANDS
Cursor Keys
? Print help
a Aperture sum, moment parameters, and gaussian fit
col line mag flux sky npixels rmom ellip pa peak fwhm
b Box coordinates for two cursor positions - c1 c2 l1 l2
c Column plot
d Load the image display
e Contour plot
f Redraw the last graph
g Graphics cursor
h Histogram plot
i Image cursor
j Fit 1D gaussian to image lines
k Fit 1D gaussian to image columns
l Line plot
m Statistics
image[section] npixels mean median stddev min max
n Next frame or image
o Overplot
p Previous frame or image
q Quit
r Radial profile plot with gaussian fit and aperture sum values
s Surface plot
u Centered vector plot from two cursor positions
v Vector plot between two cursor positions
w Toggle write to logfile
x Print coordinates
col line pixval [xorign yorigin dx dy r theta]
y Set origin for relative positions
z Print grid of pixel values - 10 x 10 grid
Colon Commands
allframes Cycle through all display frames to display images
angh s Horizontal angle for surface plot
angv s Vertical angle for surface plot
autoredraw cehlrsuv Automatically redraw graph after colon command?
autoscale h Adjust number of histogram bins to avoid aliasing
background jkr Subtract background for radial plot and photometry?
banner cehjklrsuv Include standard banner on plots?
boundary uv Boundary extension type for vector plots
box cehjklruv Draw box around graph?
buffer r Buffer distance for background subtraction
ceiling es Data ceiling for contour and surface plots
center jkr Find center for radial plot and photometry?
constant uv Constant value for boundry extension in vector plots
dashpat e Dash pattern for contour plot
eparam cehjklrsuv Edit parameters
fill e Fill viewport vs enforce unity aspect ratio?
fitplot r Overplot gaussian fit on data?
floor es Data floor for contour and surface plots
interval e Contour interval (0 for default)
label s Draw axis labels for surface plot?
logfile Log file name
logx chjklruv Plot x axis logrithmically?
logy chjklruv Plot y axis logrithmically?
magzero r Magnitude zero for photometry
majrx cehjklruv Number of major tick marks on x axis
majry cehjklruv Number of major tick marks on y axis
marker chjklruv Marker type for graph
minrx cehjklruv Number of minor tick marks on x axis
minry cehjklruv Number of minor tick marks on y axis
naverage cjkluv Number of columns, lines, vectors to average
nbins h Number of histogram bins
ncolumns ehs Number of columns in contour, histogram, or surface plot
ncontours e Number of contours (0 for default)
ncstat Number of columns in statistics box
nhi e hi/low marking option for contours
nlines ehs Number of lines in contour, histogram, or surface plot
nlstat Number of lines in statistics box
pointmode chjkluv Plot points instead of lines?
radius r Radius of object aperture for radial plot and photmetry
round cehjklruv Round axes to nice values?
rplot jkr Radius to plot in 1D and radial profile plots
select Select image or display frame
sigma jk Initial sigma for 1D gaussian fits
szmarker chjklruv Size of marks for point mode
ticklabels cehjklruv Label ticks?
title cehjklrsuv Optional title for graph
top_closed h Close last bin of histogram
unlearn cehjklrsuv Unlearn parameters to default values
wcs World coordinate system for axis labels and readback
width jkr Width of background region
x [min max] chjklruv Range of x to be plotted (no values for autoscaling)
xlabel cehjklrsuv Optional label for x axis
xorder jkr X order of surface for background subtraction
y [min max] chjklruv Range of y to be plotted (no values for autoscaling)
ylabel cehjklrsuv Optional label for y axis
yorder r Y order of surface for background subtraction
z1 h Lower intensity value limit of histogram
z2 h Upper intensity value limit of histogram
zero e Zero level for contour plot
EXAMPLES
cl> imexam dev$pix nframes=2
[The image is loaded in the display if not already loaded]
BUGS
SEE ALSO
This page automatically generated from the iraf .hlp file. If you
would like your local iraf package .hlp files converted into HTML
please contact Dave Mills at NOAO.dmills@noao.edu