Instructions for the MIIPS Package for Unix This file explains how to compile, link, and use the routines in the MIIPS Package on a Unix machine. Both Linux and Mac OS X are supported. The package supports FITS files with NAXIS=2 or 3 and of extension type IMAGE. If other extension types such as TABLE are contained in a FITS file, they are at present, ignored. In the terminology used in the package, image extensions are referred to as "maps". Currently, a maximum of 256 maps are allowed in a FITS file. Also included with the MIIPS pacage are the plot package programs plotcom.exe, xyplot_ascii.exe which are used for directing a plot file to any supported plot device, for plotting data from an ASCII file on any supported plot device, and for plotting data from one ASCII file against another, respectively. Once you have miips_unix.tar-gz available on your Unix machine, just enter gzip -d miips_unix.tar.gz tar -xf miips_unix.tar from a desired directory location. The top level of the package, which contains the executables, is MIIPS, the make files and the source code for the options are in MIIPS/miips, and all other source, include files, documentation, and sample files are in lower level directories. After the executables are on your system, you should define some aliases which are described further below. If you wish or need to recompile, proceed as folows: For Linux on Intel processors, and for Mac OS X on Intel processors, you will need to have installed on your system the Portland Group f77 compiler (http://www.pgroup.com). A free 15-day trial version of their compiler is available from their website. Their compiler also works for Solaris on Intel processors, but I have not tested this. Presumably, the Linux makefile should work for their compiler on Solaris as well. Their compiler from a few years ago was 32-bit, whereas their latest compiler is 64-bit. However I did experience some difficulties compiling in 64-bit mode, so the make files specify 32-bits. The executables compiled in 32-bit mode will run on either 32- bit or 64-bit computers. For Linux, with the earlier 32-bit Portland Group compiler from a few years ago, just enter make linux from the MIIPS/miips directory. For Linux with the later 64-bit Portland Group compiler enter make linux32 from the MIIPS/miips directory. For Mac OS X, enter make macosintel For whichever method you use to install the executable files, you may wish to create the aliases: alias a 'transparent_mode.exe' alias ax 'transparent_mode_x.exe' alias axn 'transparent_mode_xn.exe' alias plot 'plotcom.exe' alias xyplot 'xyplot_ascii.exe' "a" will change from the Tektronix window to the text window in a graphics terminal. "ax" will change from the Tektronix window to the text window in xterm, and erase the screen. "axn" will change from the Tektronix window to the text window in xterm, without erasing the screen. "plot" will operate the plot command on the standard plot files (see below) "xyplot" will produce an XY plot of columnar data from one or more ASCII files. These definitions can be placed in a login file if desired. Finally, edit display-plotting_availability.dat to match the display and plotting devices availabile on your system. If you don't wish to compile, executable versions of miips and the plotting software for Linux and Mac OS X are included in the downloaded files. Running miips.exe If you will be displaying FITS files, you should first start the enhanced version of SAOimage which is available from the MIIPS website. Note that the current code for enhanced SAOimage currently only runs on 32-bit Unix systems. If you will be displaying plots, be sure to use xterm or xgterm, also available from the MIIPS website on the plot download page. After launching the miips program you will be presented with the following prompt: Enter an option: OPTION= One can enter HE or he for help, in which case the following is displayed: MIIPS There are three help levels: 1) Entering HE will give the present listing. 2) Entering HE SU, where SU represents the first two letters of one of the subdivisions listed below, will give a list of the options available within that subdivision category, e.g., enter HE AR to see a list of the ARithmetic commands. HE * gives all of the commands. Lower case letters will work also. 3) Entering HE DOC OP where OP represents the first two letters of the selected option will give a detailed description of that option. The information can be printed or displayed on the monitor, e.g., enter HE DOC NI to see a detailed description of option NI. SUBDIVISIONS: AR Arithmetic (real, complex, and flatfields) CA Calibration (flux, photographic, wavelength) CO Coordinates, Transforms (XY, RA and DEC) and Velocities DI Display (line plots and images) ED Edit (headers and data) FI Filter (1D, 2D, real or complex) PH Photometry (stellar, surface, or spectral) TO Topology (rotate or move maps,lines, or bits) UT Utilities (statistics, curve fits, etc.) **************** The list of options for each category or subdivision is more than is currently implemented in this version of MIIPS. Of the approximately 100 options available in the VMS version, only about 26 are presently available. They are: AC Dispays contour plots of FITS maps AR Performs simple arithmetic on FITS maps AV Computes column averages of FITS maps CR Crops a FITS file DA Displays the output from option EA EA Calculates a surface brightness distribution in a simple way EC Edits pixel values in circles EP Edits single pixel values ER Edits pixel values in rectangular areas EX Exits MIIPS FI Finds the locations of objects in a FITS map FA Creates artificial star images FG Creates artificial galaxy images FM Flips a map horizontally or vertically FS Flattens a spectrum HE Gives help IP Does simple image processing and SAOimage control MA Operates on a FITS map with a mask file NI Creates artificial noise for a FITS map PH Prints a FITS header PL Plots a cut through a FITS map PT Prints pixel values on the terminal RG Computes the parameters of a surface brightness distribution RO Rotates a FITS map by an arbitrary angle ST Computes various statistics of a selected area in a FITS map TV Does simple initialization of SAOimage Note that an option can be entered as either upper case or lower case. Every time an option is executed, a file with the name XX.sve, containing the keywords associated with the user prompts, and their corresponding paramater values, is written to disk. This file is different than the log file, and is known as a save file. "XX" stands for the two-letter option just run. By simply entering .xx or .XX the option will be rerun without the user having to respond to any prompts. If you desire to reun the option with different input values, proceed as follow: If the first option was PH with a file name of "miips/samples/tst0001.fits", and you wish toe rerun it with file tst0002.fits, then enter .PH(FILE=miips/samples/tst002.fits) Both the two-letter option, and the keyword "FILE" can be upper or lower case. Working with the Plot Programs Plotting is built into testfits.exe. A plot can be sent to one or more plot devices and plot file simultaneously. The plot devices that appear in the list presented to the user are determined by settings in the file display-plotting_availability.dat. Simply uncomment or comment those devices you wish to be or not be shown. When the plot first appears on the selected device(s), help can be obtained by typing (not entering) the letter h or H. The following will then appear (note that ^ denotes that the control key is to be pressed as well): A = Turns on the crosshairs and by pressing the at chosen X limits, the mean Y value will be calculated for each plot. a = Allows the user to enter annotation at the location of the crosshairs with the color most recently selected. ^I (^L on Mac OS X) toggles to the Greek alphabet and special symbols, and back to English ^H (^B on Mac Os X) gives a backspace ^K toggles to subscript, superscript, and back to normal ^A = Prompts user for the height of the annotation. B = Defines a box with the crosshairs placed at the lower left and upper right. Will replot with this scaling. b = Allows the user to be prompted for the background color on Enhanced SAOimage. C = Turns on the crosshairs and by pressing the , prints the values at that location and puts the values in a common block; typing - deletes the last pair of values from the common block; and typing Q turns off the crosshairs. c = Allows the user to be prompted for the color, e.g., on Enhanced SAOimage. F = Allows the user to alter the scaling factor on the current plot device(s). f = Allows the user to change the fill style for each plot. H = Gives help. h = Gives help. I = Allows the user to be prompted for several of the plotting parameters before a replot is done. This command is typically used when preparing a plot for publication. The following operations are available: 1) Inverting the X axis and/or Y axis 2) Labeling the X and Y axes in the following ways: Linear automatic, Linear manual, Antilog automatic, Antilog manual (antilog refers to the fact that the labeling is the antilog of the plotted values which are logs) a) In the Linear manual mode one can specify for the X and Y axes, the lowest labeled physical value, the physical value/interval, and the number of intervals (coded as nn.llrr where nn is the integer part, .ll represents the left (or bottom) fractional part, and .rr represents the right (or top) fractional part of an interval). b) In the Antilog manual mode one can specify for the X and Y axes, the lowest displayed tick mark (coded as log.antilog where log is the integer part of the plotted value (which is a log), and antilog represents the first displayed tick mark of that decade (which is an antilog)). The antilog of the physical value at the first tick mark may or may not be printed byu the program. One can also specify the number of displayed decades (coded as n.antilog where n is the integer part of the number of decades, and antilog represents the rightmost displayed tick mark of an additional decade. For example, if one enters -1.5 for the lowest value and 3.2 for the number of decades, then the first tick mark will be at X=0.5 (log = -0.301 = -1 + 0.699) and the last tick mark will be at X=200 (log = 2.301). Note that fractional parts of .0 and .1 behave the same way. Note: If the original plot was linear, then the log of the data should be taken first (with the L command) for the antilog labeling to make sense. 3) Specifying symbol heights 4) Specifying labels for the X and Y axes 5) Specifying a title 6) Specifying one or more print devices L = Allows the user to take log(X) and log(Y). l = Allows the user to take ln(X) and ln(Y). M = Allows the user to modify the X and Y values by adding increments and adjusting by scaling factors. m = Allows the user to modify the X and Y values by adding increments and adjusting by scaling factors for a selected plot. O = Redoes the original plot with any new axes, colors, and symbols. o = Redoes the original plot without any new axes or symbols. P = Allows the user to take powers. p = Allows the user to specify the color of each plot. Q = Returns. q = Returns. R = Turns on the crosshairs and by pressing the at chosen X limits, replotting with automatic scaling will be done. S = Allows the user to specify the style of vector. s = Allows the user to specify the symbol for a set of points. V = Draws a vector of the color and vector style most recently selected. v = Allows the user to be prompted for the starting and ending physical values of a vector. X = Allows plotting an additional X axis in different linear units. x = Allows plotting an additional X axis in different antilog units. Y = Allows plotting an additional Y axis in different linear units. y = Allows plotting an additional Y axis in different antilog units. On SAOimage and xgterm, user prompts appear on the text terminal whereas on all other devices the prompts will appear on the Tek window. Note that a plot can be sent to more than one device at a time. Xgterm, a color xterm, behaves mostly like xterm. One difference between the two is that xterm allows one to use the left mouse button to interact with the plot whereas xgterm requires a press. SAOimage also requires a press for plot interaction. SAOimage on Mac OS also requires that it be given focus by clicking in the frame before any interaction is attempted. Following that, the cross cursor should be positioned within the SAOimage desktop area before and commands are given. The version of SAOimage available from most sources will not work with plotting; the version that is required is "Enhanced SAOimage, v. 1.24", available at the MIIPS website. The plot device xgterm is a color xterm-like graphics terminal emulator which runs on Unix. Copies for various operating systems can be found on the website. Xgterm needs to have its colors defined in the user's .Xdefaults file. The following entries will ensure that the correct colors are displayed: Xgterm*gterm*color0: black Xgterm*gterm*color1: ivory1 Xgterm*gterm*color2: red Xgterm*gterm*color3: green Xgterm*gterm*color4: blue Xgterm*gterm*color5: cyan Xgterm*gterm*color6: yellow Xgterm*gterm*color7: magenta Xgterm*gterm*color8: gold1 Xgterm*gterm*color9: DarkSlateGray3 Xgterm*gterm*height: 601 Xgterm*gterm*width: 801 If a plot file is being created it is possible to add annotation that will be written to the file. For example, if one selects DEVICES=X F the plot will appear on an xterm and be written to a file. Pressing "a" while the plot is displayed on an xterm will then bring up a cursor. Position the cursor on the plot and then click the left mouse button (or press the for xgterm and SAOimage). You are then prompted to enter some annotation. You can enter either English text, Greek letters, special symbols, or some combination of them. Typing ^I (^L on Mac OS X) at this time, toggles to the Greek alphabet and special symbols, and back to English. In the Greek mode, the numbers 0 to 9 produce the symbols 0 to 9. One could for example use special symbol 1 (a circle) to denote the position of the primary in a plot of a relative orbit. Note however, that the cursor center currently corresponds to the lower left corner of the initial character. The Plot Command After a plot file has been created, the plot can at any time be directed to any of the available plot devices by using the plotcom.exe program. Since the plot file's default name is plot.plt, be sure to change this to some other name to avoid having it be overwritten by another plot file. To plot a plot file, first be sure that you have set up the alias 'plot' as described above. Enter: plot device=P xoff=X yoff=Y scale=S rotate=R number=N input_plot_file where 1) Each optional keyword, and in the case of "device", its value, can be shortened to an unambiguous abbreviation 2) If no device is specified, the default is xterm 3) If no plot_file is specified, the default is plot.plt 4) An optional / delimiter can be used between keywords (but not before the first one) 5) The keywords have the following meaning: device is the plot device, with values, P, equal to TEKTRONIX = Graphics terminal (VT100/Retrographics and Visual 550) GRAPHON = Graphon graphics terminal CODONICS = Codonocs graphics terminal MICROTERM = Microterm graphics terminal VERSATERM = Versaterm graphics terminal emulator for Macintosh XTERM = Xterm graphics terminal emulator for OpenVMS and Unix XGTERM = Xgterm grpahics terminal emulator for Unix SAOIMAGE = Enhanced SAOimage _SAOIMAGE = Enhanced SAOimage with not erasure of the previous image POSTSCRIPT = Postscript output file (default name is plot.ps) EPS = Encapsulated postscript output file (default name is plot.eps) (each device can be shortened to an unambiguous abbreviation, e.g. pos or POS for POSTSCRIPT) xoff is the horizontal offset, X, of the plot in inches yoff is the vertical offset, Y, of the plot in inches scale is the magnification, S, of the plot in terms of a factor. rotate is the counterclockwise rotation, R, of the plot in degrees number is the number, N, of the complete plot within the plot file. Because the plot file is not closed until testfits quits, all plots are written to the same file, and the "number" keyword must be used to select the plot. 6) The keywords and their values can be upper- or lowercase 7) When both rotation and offsets are given, the operation can be thought of as either 1) rotation about the lower left corner of the plot followed by translation in the rotated coordinate system, or 2) translation followed by rotation about the old location of the corner. Thus a plot on xterm can be viewed rotated 90 counterclockwise with a command such as: plot yof=-6 rot=90 sca=0.75 myplot.plt 8) Postscript files created by the plot command are by default matched to a printed sheet viewed in landscape orientation. Thus when such a file is viewed with ghostview or another postscript viewer, they will appear to be rotated by 90 degrees counterclockwise. To create a postscript file without the prerotation, use a command such as: plot dev=pos xof=-8.0 rot=-90 myplot.plt 9) Encapsulated postscript files are by default not prerotated and will appear in the correct orientation in ghostview. In addition, encapsulated postscript files are by default created with a bounding box size just slightly larger than the default XY plot size (X axis = 6 inches, Y axis = 5 inches). If your plot size is larger or smaller than the default size just use an editor such as vi to change the dimensions in the *.eps file. The BoundingBox line is 5th from the top. The encapsulated postscript files will not ordinarily produce output on a printer because because they do not contain the 'showpage' command. If you wish to see a printed version of your eps file, just add 'showpage' after the last 'stroke' command on the third line from the end. 10) The keyword, number, selects the number of the plot within a multi-plot file. If the number keyword is not given, by default the first plot is displayed on devices such as graphic terminals, xterm, xgterm, and SAOimage. If a postscript file is created and no number keyword is given, all plots are written to the file. For an eps file, only the first file is written. If the value given for the number keywords is -1, then all plots are displayed overlapped on all devices, postscript files, and eps files. Plotting from an ASCII File One or more ASCII files of data can be plotted with the program xyplot_ascii.exe, a general purpose interface for the xyplot.for. Three cases can be handled. In the first case, the data for the abscissa and ordinate are contained in one file having an arbitrary number of header lines, an arbitrary number of columns, and an arbitrary number of rows of data. All columns must have the same number of rows however. Multiple plots are possible by selecting more than one column for the abscissa and ordinate. The number of columns chosen for the abscissa and ordinate must match. In the second case, the data for the abscissa are contained in a first file and the data for the ordinate are contained in a second file. The number of rows in both files, other than header rows, must match. Multiple plots are again possible. In the third case, the abscissa and ordinate data for the first plot are contained in the first of several files, and the abscissa and ordinate data for additional plots are contained in additional files up to a maximum of fifteen plots. This is the most general case because the numbers of rows do not have to match between files. In all three cases the data can be in the form of decimal or integer values. A setup file needs to be opened which sets up the line dashing, pen width, line style, symbols, and colors. By editing this setup file, many different graphs can be produced. In the setup file, the name of the control parameter is followed on successive lines by the values desired for each plot. The control parameters may be in any order. The number of values can be less than, equal to, or greater than the number of plots desired. The program will simply use the values up to the last one available, and then roll the values over. The file xyplot_setup1.dat, shown below, is an example of this format: LINE VECTOR STYLE 0 0 0 0 0 0 0 1 2 3 4 5 PEN WIDTH 20 LINE TYPE -1 0 997 997 -1 997 997 SYMBOL 0 1 100 100 327681 100 100 5 6 7 8 9 10 INVERT X NO INVERT Y NO COLOR 16776960 Yellow 16711935 Magenta 65280 Green 65280 Green 16711680 Red 8388564 Aquamarine 8388564 Aquamarine 255 Blue 16766720 Gold1 65535 Cyan 7982541 DarkSlateGray3 16777200 Ivory1 10824234 Brown 16716947 Deep pink 5597999 Dark olive greem 15631086 Violet 16766720 Gold 16770229 Moccasin X LABEL X Axis Y LABEL Y Axis TITLE Anonymous 1) Each keyword is followed, on successive lines, by the values for a single plot within the complete plot. If there are more plots than values, rollover will occur. If there are fewer plots than values, the extra ones will not be used. 2) The keywords may be in any order 3) Comments are allowed to the right of a value, however it is very important that there be no tabs in the line. 4) The LINE TYPE (as explained in line.for) controls the plot lines and the type of plot, where: a) The magnitude of the value controls the frequency of plotted symbols, e.g. zero gives no symbols, and 4 gives a symbol every 4th data point b) Positive values give a straight line connecting every data point c) Negative values give no connecting straight lines d) If the value is 997 error bars are drawn (two plots are required) e) If the value is 998 a histogram is drawn with the bars stacked vertically if multiple plots are made f) If the valud is 999 a histogram is drawn with the bars placed next to each other is multiple plots are made 5) The SYMBOL controls the type of symbol where a) values from 0 to 13 in the first byte give the built-in symbols b) a character may be plotted if the ASCII code is placed in the second byte c) if a histogram is to be drawn, the value in the first byte give the filling style d) if error bars are to be drawn, the value in the first byte give the style of the bar, i.e., 0 give a short tick, 1 gives nothing, 2 gives an arrowhead. If 100 is added to the first byte, the X or Y locations contain the central location and the deviation to the low and high directions, respectively, for the adjacent array locations. Because errorbars require two plots, the values should be repeated. e) the value in the third byte give the symbol height in hundredths of an inch. If the value is not present a default of 0.14 inch is used. In the above example setup file, the values under LINE TYPE and SYMBOL indicate that the first plot will consist of points drawn with symbol number 0 with no connecting lines, and the second plot will have connecting lines between the points with no symbols drawn. The third plot will be error bars drawn with the usual short ticks at the ends. Because error bars require two adjacent plot array locations, the values for each keword are repeated. The fourth plot will consists of points drawn with symbol number 1, but because the symbol is to be drawn with a smaller size of 5/100 inches, 5 is added to the 3rd byte, giving a final value of 1 + 5*256**2 = 327681. A future version of xyplot_ascii will attempt to make this operation more user friendly. The next plot is again error bars, requiring repeated values. Five sample ASCII files are included in this package to demonstrate how xyplot_ascii.exe works. Launch the program, and you will be presented with the following menu: Enter a choice for the input data: 1 = Abscissa and ordinate data for one or more plots in one file (default) 2 = Abscissa data in one file and ordinate data in another file for one or more plots 3 = Abscissa and ordinate data for first plot in first file, additional data for additional plots in successive files, up to a maximum of ten files CHOICE= Enter 1, and the program responds with: Open the file containing the abscissa and ordinate data for one or more plots. Enter the file name: FILE= Enter ascii1.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER_1= Enter 1 or take the default, and the header line will be displayed, along with the counts of the number of columns of data and the number of lines of data. The program then asks: Enter the column(s) to be plotted as abscissa values: COLUMNS_ABSCISSA= Here we are going to plot the data in column 2 against time in column 1, plot the curve in column 6 against time, and plot error bars for the data. Because all abscissa values originate from column 1, and because there are 4 plots (data, curve, and error bars requiring 2 plots) we enter 1 1 1 1. The program then asks: Enter the column(s) to be plotted as ordinate values: COLUMNS_ORDINATE= We enter 2 6 2 3 (column 2 for the data, column 6 for the curve, column 2 for the central location of the error bar, and column 3 for the amplitdue of the error bar). Now the program asks for the name of the setup file: Open the setup file: (default = xyplot_setup.dat) SETUP_FILE= Enter xyplot_setup1.dat (do not take the default) and the program then asks Enter the plot devices: S = SAOimage (Enhanced version) -S = SAOimage, no erasure of screen G = Graphics terminal (VT100/Retrographics and Visual 550) G4 = Graphics terminal emulator (Versaterm) X = Xterm (default) XG = Xgterm F = File Enter the appropriate device name, and you will see the plot. If you enter 1 1 1 1 1 1 1 for the abscissa columns, and 2 6 2 3 4 4 5 for the ordinate columns, you will see an additional set of data points plotted with a different symbol, a different symbol size, a different error bar length, and different colors (if you are using a color display). ************* Launch xyplot_ascii.exe again and this time enter 2 for the choice of input data. In this case, the abscissa data come from one file and the ordinate data from a second file. The program responds with: Open the file containing the abscissa data for one or more plots. Enter the file name: FILE= Enter ascii2.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER_1= Enter 1 or take the default, and the header line will be displayed, along with the counts of the number of columns of data and the number of lines of data. The program then asks: Enter the column(s) to be plotted as abscissa values: COLUMNS_ABSCISSA= Enter 1 1 1 1. The program then asks: Open the file for the ordinate Enter the file name: FILE= Enter ascii1.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER_2= Enter 1 or take the default, and the header line will be displayed, along with the counts of the number of columns of data and the number of lines of data. The program then asks: Enter the column(s) to be plotted as ordinate values: COLUMNS_ORDINATE= Enter 2 6 2 3, as before, and the program asks: Open the setup file: (default = xyplot_setup.dat) SETUP_FILE= Enter xyplot_setup1.dat, as before, and the program then asks Enter the plot devices: S = SAOimage (Enhanced version) -S = SAOimage, no erasure of screen G = Graphics terminal (VT100/Retrographics and Visual 550) G4 = Graphics terminal emulator (Versaterm) X = Xterm (default) XG = Xgterm F = File Enter the appropriate device name, and you will see a plot which differs from the first one in that the abscissa values are larger by a factor of 100. ************* Launch xyplot_ascii.exe again and this time enter 3 for the choice of input data. In this case, the abscissa and ordinate data for the first plot are contained in the first of several files, and the abscissa and ordinate data for additional plots are contained in additional files up to a maximum of fifteen plots. The program responds with: Open the file containing the abscissa and ordinate data for the first plot. Enter the file name: FILE= Enter ascii3.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER= Enter 13, and the program will report the number of columns of data and the number of lines of data, and then ask: Enter the column(s) to be plotted as abscissa values: COLUMNS_ABSCISSA= Enter 1 1 1, (the columns for the x data points and their error bars). Then the program asks: Enter the column(s) to be plotted as ordinate values: COLUMNS_ORDINATE= Enter 2 2 3, (the columns for the y data points and their error bars), and the program responds with: Enter the name of the input file for an additional plot; enter 0 to continue: FILE= Enter ascii4.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER= Enter 13, and the program will report the number of columns of data and the number of lines of data, and then ask: Enter the column(s) to be plotted as abscissa values: COLUMNS_ABSCISSA= Enter 1, (the column for the x data of a single curve). Then the program asks: Enter the column(s) to be plotted as ordinate values: COLUMNS_ORDINATE= Enter 2, (the column for the y data of that curve). The program next asks: Enter the name of the input file for an additional plot; enter 0 to continue: FILE= Enter ascii5.dat, and the program asks: How many lines are in the header? (default = 1) LINES_HEADER= Enter 13, and the program will report the number of columns of data and the number of lines of data, and then ask: Enter the column(s) to be plotted as abscissa values: COLUMNS_ABSCISSA= Enter 1 1 1, (the columns for the x data points and their error bars for another set of data). Then the program asks: Enter the column(s) to be plotted as ordinate values: COLUMNS_ORDINATE= Enter 2 2 3, (the columns for the y data points and their error bars). The program next asks: Enter the name of the input file for an additional plot; enter 0 to continue: FILE= Enter 0, because we are done entering the ascii files of data. Now the will ask: Open the setup file: (default = xyplot_setup.dat) SETUP_FILE= Enter xyplot_setup2.dat (don't take the default). Then you are asked: Enter the plot devices: S = SAOimage (Enhanced version) -S = SAOimage, no erasure of screen G = Graphics terminal (VT100/Retrographics and Visual 550) G4 = Graphics terminal emulator (Versaterm) X = Xterm (default) XG = Xgterm F = File DEVICES= Enter your current graphics device and a plot with two sets of data with error bars, and a curve with a dashed line will be displayed. You can then use the built-in interacive commands of xyplot to rescale, arithmetically tranform the data, add annotation, and send the plot to the same or a different device, or a file. Any questions should be directed to Donald Gudehus at gudehus@chara.gsu.edu.