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diff --git a/pkg/plot/doc/implot.hlp b/pkg/plot/doc/implot.hlp new file mode 100644 index 00000000..4d97e0e7 --- /dev/null +++ b/pkg/plot/doc/implot.hlp @@ -0,0 +1,231 @@ +.help implot Feb94 plot +.ih +NAME +implot -- plot lines and columns of images +.ih +USAGE +implot image [line] +.ih +PARAMETERS +.ls image +List of images to be plotted. If more than one image is in the list then +the 'm' and 'n' keys are used proceed to the previous and next image. +.le +.ls line +If given, the number of the image line to be plotted, otherwise the central +line is plotted. +.le +.ls wcs = "logical" +The world coordinate system (\fIwcs\fR) to be used for axis labeling. +The following standard world systems are predefined. +.ls logical +Logical coordinates are image pixel coordinates relative to the image currently +being displayed. +.le +.ls 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. +.le +.ls world +The "world" coordinate system is the \fIcurrent default WCS\fR. +The default world system is the system named by the environment variable +\fIdefwcs\fR 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. +.le + +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. +.le +.ls step = 0 +Step size for stepping through lines or columns in an image with the +'j' and 'k' keys. If zero or INDEF the step defaults to ~10% of the +image axis length. This parameter may be changed interactively with +a colon command. +.le +.ih +DESCRIPTION +Implot is an interactive, cursor driven task for examining images by plotting +the lines and columns or the averages of lines and columns. An image +line is plotted when the task is first run, then cursor mode is entered and +keystrokes may be used to generate additional line and column plots. 'q' +is typed to exit cursor mode and implot and 'n' is typed to proceed to +the next image in the input image list. + +The following single character keystrokes are recognized by Implot. Note that +numerous additional keystrokes are provided by "cursor mode" itself, i.e., +by the graphics system. These additional keystrokes provide such standard +facilities as stepwise cursor motion, plot expansion, movies, disposal to a +batch plotter or metafile, and plot annotation facilities. Cursor mode is +documented elsewhere. + + +.ks +.nf + ? print help and other info + a plot the average of a range of lines or columns + c plot a column + e expand plot by marking corners of viewport + j move down within image (moving section) + k move up within image (moving section) + l plot a line + m proceed to the previous image in the list + n proceed to the next image in the list + o overplot next vector + p measure profile (mark region and bkg with 2 pos) + q quit + s print statistics on a region + w change world coordinate system + / scroll status line + <space> print coordinates and pixel value +.fi +.ke + + +The single character keystroke commands use the position to the cursor to +determine what region of the image to plot. If the plot is examined carefully +one will note an extra scale on the right hand edge. This scale gives the +"other" axis of the image in units of pixels. For example, if the current +plot is a line plot (rather than a column plot), the X axis of the plot +will correspond to the X axis of the image, and the right Y axis of the plot +will correspond to the Y axis of the image. Both axes will be scaled +linearly in units of pixels. The left Y axis is scaled in either linear or +logarithmic pixel intensity units. In the case of a column plot the bottom +axis will correspond to image Y and the right axis to image X. + +The 'l' and 'c' keystrokes, used to plot lines and columns, take image +coordinates from the bottom and right axes of the plot. In the case of a +lineplot, the cursor would be positioned in Y and the key 'l' typed to +plot a new line. Extrapolation of this convention to the other cases and +keystrokes is self evident. The 'a' keystroke is used to mark an X or Y +region to be averaged and plotted. This mode of averaging is independent +of the ':a' command discussed below. + +Successive vectors may be overplotted by typing an 'o' and then any other +command. A range of linetypes are used if the device supports them to +make the curves easier to distinguish. The position of each line is marked +on the right axis with a small tick to document the coordinates of the +curves. + +The 'j' and 'k' commands are used to step through an image in either the +upward (k) or downward (j) directions, relative to the current line or +column plot. Each new vector is plotted in place of the previous one +without clearing the screen, making it easy to compare successive vectors. +The step between vectors may be defined by a task parameter and +changed by a colon command. + +The 'm' and 'n' commands are used to step through the input image list. +This is the same as using the 'i' key to switch images and the 'l' key +to plot the same line or column as the previous image. + +There are three keys which print various quantities of interest. +The space bar key will read the cursor position, find the nearest pixel, +and report the image line and column, the coordinate along the current +axis, and the pixel value. The line and column are in logical pixels +(that is the coordinates in the current image section) and the +coordinates are in the selected world coordinate system and printed +in the current coordinate format. If the selected world coordinate +system is "logical" then the coordinate will be the same as the line +or column. + +The 's' key requires two cursor positions and then computes statistics of +the region. The values are the median, mean, sigma, sum, and number of +pixels. The 'p' key also requires two cursor positions with the x +positions defining a region and the y positions defining a linear +background. Within the defined region the peak departure from the +background (either above or below the background) is found and the full +width at half maximum of this peak is measured. The linear background, the +peak position and distance from the background and the widths at half the +peak value are overplotted on the data. In addition to the profile +quantities the moments of the background subtracted data are measured. The +moments computed are the centroid, the integral (or flux), the width, and +the normalized asymmetry. The width reported is the square root of the +second central moment multiplied by 2.35482. For a gaussian profile this +corresponds to the full width at half maximum which can be compared with +the direct measure of the profile width. The normalized asymmetry is the +third central moment divided by the 3/2 power of the second central +moment. The various measurements are printed on the status line. There +are multiple lines of results which are scrolled using the '/' key. + +In addition to the single keystroke commands, the following : escape +commands are provided: + + +.ks +.nf + :a N set number of lines or columns to average + :c N [M] plot column N [average of columns N to M] + :f format set the x coordinate numerical format + :i imagename open a new image for input + :l N [M] plot line N [average of lines N to M] + :o overplot + :log+ log scale in Y + :log- turn off log scale in Y + :step N set step size for j,k + :solid overplot with solid, not dashed, lines + :w wcsname change world coordinate systems + :x x1 x2 fix range in X (call with no args to unfix) + :y y1 y2 fix range in Y (call with no args to unfix) +.fi +.ke + + +The 'c' and 'l' commands are identical to the keystroke commands except +that the column or line position is explicitly entered rather than taken +from the cursor. An averaging factor entered with 'a' will apply to all +subsequent line and column plots, as well as plots generated by 'j' and 'k'. +The input image may be changed at any time using the 'i' command; only one +image may be open at a time. Log scaling on the Y axis may be turned on +and off with the 'log' commands. The default step size of 1/10 the height +of the image may be changed with the 'step' command. Finally, the 'solid' +command may be used to draw all overplotted curves using solid, rather than +dashed, line segments. + +The 'x' and 'y' commands may be used to fix the plotting scale in either +X or Y, i.e., to disable autoscaling. Once the scale is fixed on an axis +it remains fixed until either the fix scale command is repeated without +any arguments, or the 'e' option is used to expand the plot (this causes +the fixed scale to be lost). Plotting different lines or columns or even +changing images does not cause loss of fixed scaling. If the X scale is +fixed to a range less than an entire line or column Y autoscaling, if enabled, +will only pertain to the displayed range in X. + +The numerical format for the coordinate labels are set with the 'f' +command. 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. Some images have a recommended x +coordinate format defined as a WCS attribute. If the format value is "" +(the default) the WCS attribute format will be used. Any other value will +override the image attribute. +.ih +EXAMPLES +1. Enter cursor mode, plotting line 240 of the 300x480 image 'crab': + +.nf + cl> implot crab + (plot appears) +.fi + +Type '?' to get the list of recognized keystrokes. Move the cursor and +type 'l' to plot the line at the Y position of the cursor. Try typing 'c' +to plot a column (note that a column plot will take longer than a line +plot since the entire image must be read). Go back to a line plot and +try several 'k' keystrokes to step up through the image. Try a cursor +mode 'E' to playback a movie of a small region, then type 0 (zero) to +restore the original plot. +.ih +BUGS +It should be possible to use the image display cursor to mark the lines or +columns to be plotted. This capability will be added when the image display +is interfaced to GIO (the IRAF graphics subsystem). +.ih +SEE ALSO +imexamine, cursor +.endhelp |