1 ASTROMETRIC ASTROMETRIC [RAmin RAmax DECmin DECmax] [/MAGNITUDE Mlim] [/EPOCH date] [/OUTPUT File] Search and plots all astrometric stars of magnitude less than Mlim (brighter than Mlim) in the (RA,DEC) box specified by RAmin RAmax DECmin DECmax (if present, and in the current Greg box otherwise, provided that the coordinate system is equatorial). The current marker type is used and the size depends on the current marker size and on the star magnitude. The proper motions are included to represent the sky at the date specified in the /EPOCH option if present, at the current day otherwise. The stars are precessed to current equinox, as defined in variable GEPOCH. If option /OUTPUT is present, star positions, magnitudes, spectral types and names are written in the specified file (which defaults to user terminal). NOTES: - Palomar/SRC Survey Schmidt Plates (POSS#I) are squares of size 35.56 cm (14 inches) with a scale of 67.14 Arcsec. per mm. - ESO Survey Plates are squares of size 30 cm with a scale of 67.6 Arcsec. per mm. If you want to make overlays, do not forget the /EXACT option in command HARDCOPY/PLOT ... 1 FLASH [ALL\]FLASH [Filename] [/PLANE I1 I2] [/SUBSET Imin Imax Jmin Jmax] Displays the GILDAS byte image Filename. The image values must be in the range 0-241 (unsigned bytes) to be immediately displayed on the image processor. This command is intended for quick look to an image. Hence, no scaling occurs, and the byte image is not transmitted to GreG, but will take the place of the image in a PostScript output if no command "PLOT" is given before asking for the OVERLAY command. However, the current Regular-Grid array stills points to the last image defined by command IMAGE, and can be displayed without computations using command PLOT. The /PLANE I1 I2 option allows to define part of a more than 2- Dimensional image as the current image. A file name should not be specified if you want to select a new plane in the current image. The /SUBSET Imin Imax Jmin Jmax option allows to load only a subset of the input image or image plane. Again, a file name should be specified only to change the input image. You can combine /PLANE and /SUBSET options. 1 RGB [ALL\]RGB [RedFilename GreenFilename BlueFilename] [RGB or SHARP or PHOTO] [/PLANE I1 I2] [/SUBSET Imin Imax Jmin Jmax] Displays three GILDAS byte images RedFilename, GreenFilename and BlueFilename, in this order, as a "truecolor" image (see HELP SAVE to know how to make such byte images). The user has the choice between three flavours for displaying on 8-bits what is essentially an 24-bits problem: using either the default (PHOTO) value, that will give more photographic washed-out colors, the "SHARP" option, same as PHOTO but without unsaturated colors, or the simple-minded "RGB" option, that divides the R,G,B cube in (cubic root of the number available colors) parts on each axis. Test it to feel the differences. The corresponding LUT is loaded along with the command, see also HELP LUT. The byte image is not transmitted to GreG, but will take the place of the image in a PostScript output if no command "PLOT" is given before asking for the hardcopy (ALL\OVERLAY command). The current Regular-Grid array stills points to the last image defined by command IMAGE, and will be displayed without computations using command PLOT. The /PLANE I1 I2 option allows to define part of more than 2-Dimensional images as the R,G,B image. The /SUBSET Imin Imax Jmin Jmax option allows to load only a subset of the input images or image planes. You can combine /PLANE and /SUBSET options. 1 HEADER HEADER [Image_Name] /EXTREMA Compute the extrema of the current or specified image, and update the header accordingly. HEADER /UPDATE Update the header of the current image, for example after modifications to the G_* header variables have been made. The header variables are G_NDIM Number of dimensions G_DIM[4] Image dimensions G_CONVRT[3,4] Conversion formula (Ref, Val, Inc for each axis) G_BLANK[2] Blanking and tolerance G_MAX Maximum value G_MIN Minimum value G_EXTREMA Zero (0) if no extrema defined G_WHERE[2,4] Pixel of maximum and minimum G_UNITi Units of axis i G_UNIT Units of map G_COORD System coordinates G_SOURCE Source name G_EPOCH Epoch of coordinates G_RA Right Ascension (of Object) G_DEC Declination (of Object) G_LII Galactic longitude (of Object) G_BII Galactic latitude (of Object) G_PTYP Projection Type (0:none,1:Gnomonic,2:Orthographic, 3:Azimuthal,4:Stereographic,5:Lambert,6:Aitoff,7:Radio). Warning: these codes are subject to change without notice. G_XAXI The first axis of projection (1,2,3 or 4) G_YAXI The second axis of projection (1,2,3 or 4) G_A0 Position of projection center for axis G_XAXI (R.A. or LII) G_D0 Position of projection center for axis G_YAXI (DEC. or BII) G_ANGLE Angle of projection (East of North) G_LINE Line name G_FREQRES Frequency resolution G_RESTFRE Signal rest frequency G_FREQOFF Image rest frequency G_VELRES Velocity resolution G_VELOFF Velocity of reference channel G_PA Position angle of beam G_MINOR Minor axis size of beam G_MAJOR Major axis size of beam G_BEAM Size of RESOLUTION section (0 or 3) HEADER [Image_Name] [/OUTPUT FIle_Name] Give the Header of the current or specified Image, on the screen or in the specified output file. Provided you have write access to the image and nobody else is already using it, the header may be edited on DEC/VMS machines if the terminal is a VT100 compatible. The keys of the VT100 keypad have the same meaning as in DEC's EDT: +--------+--------+--------+--------+ | enter | | | Del L | | edit | | | | +--------+--------+--------+--------+ | print | | | Del W | | header| | | | +--------+--------+--------+--------+ | Advance| Backup | | Del C | | | | | | +--------+--------+--------+--------+ | Word | Eol | Char | | | | | | Enter | +--------+--------+--------+ | | Line | |(Update)| | | | | +-----------------+--------+--------+ To edit a field, press the GOLD (PF1) key. To compute MAXIMA and MINIMA of current image, strike ENTER key. Strike <^Z> to exit. The header will be automatically updated if any modification has been made. 1 IMAGE [ALL\]IMAGE [Filename] [/PLANE I1 I2] [/SUBSET Imin Imax Jmin Jmax] Read the GDF map Filename. The default image extension is .GDF This command defines the image found in given file as the new current image to be used by next PLOT command. The image also becomes the current Regular Grid array in GreG. The box location is reset by this command to match the image boundary. The /PLANE I1 I2 option allows to define part of a more than 2- Dimensional image as the current image. A file name should not be specified if you want to select a new plane in the current image. The /SUBSET Imin Imax Jmin Jmax option allows to load only a subset of the input image or image plane. Again, a file name should be specified only to change the input image. You can combine /PLANE and /SUBSET options. The behaviour of this command depends on the current MODE defined by command SET MODE. In IMAGE MODE, a single plane is mapped. In CUBE MODE, the whole image is mapped. CUBE MODE is still not quite coherent with GreG languages, and should be used only for MOVIES. 1 IRAS [ALL\]IRAS Band [Ramin Ramax Decmin Decmax] [/FLUX Threshold] [/SIZE Flux_value] Plots a marker at the position of all IRAS point sources detected at band Band (specified by its wavelength in microns 12, 25, 60 or 100) in the area defined by Ramin, Ramax (in hours), Decmin, Decmax (in degrees). If the option /FLUX is given, only sources with a flux greater than Threshold will be selected. If the option /SIZE is given, the marker size will be proportional to the logarithm of the flux (sources with a flux equal to Flux_value having the current marker size as specified by SET MARKER command). The current marker type is used. Command IRAS completely ignores the current GreG box to select the IRAS point sources, but the markers will be clipped in this box when plotted. Hence, it is up to the user to ensure that the system is EQUATORIAL and that the projection area (specified by command LIMITS and PROJECTION) reasonably matches the selection area specified in command IRAS. 1 KILL [ALL\]KILL KILL calls the interactive cursor. Recognised keys are: - V to give the value of the pixel - K to give the current blanking value to the pixel - I to interpolate the value from the neighbour pixels. - E to exit from interactive cursor mode Any other key is ignored. 1 Language ALL\ Language Summary ASTROMETRIC : Plots astrometric star positions (for finding charts) FLASH File : Displays a byte image. HEADER [Name] : Give the Header of the current or specified Image. IMAGE [Name] : Read the image Name. Default extension is .GDF IRAS Band : Select and plot IRAS sources of a given band KILL [i j] : Kills pixels LIST : Show current operating modes LOOK : Use the image cursor to look for image values LUT [arg] : Change the color Look-Up-Table MOVIE : Make a movie for a cube PAN [i j] : Move the zooming window around a new pixel OVERLAY File : Make a PostScript hardcopy of image and graphics PLOT : Plot the image and redraw graphics PSC_IRAS : Get characteristics of IRAS point source REGRESSION [Val]: Computes regression lines RGB r g b [mode]: Plots 'truecolor' mix of 3 byte images SAVE File : Saves bitmap in image format. SET Mode : Select some operating mode SPECTRUM : Extract a spectrum from an image (to plot it). ZOOM : Zoom part of the image. 1 LIST [ALL\]SHOW Lists some internal parameters of the OVERLAY program : scaling mode, range, etc... 1 LOOK [ALL\]LOOK Examine pixel values using the mouse pointer. Click central button for examining values, left button to exit. 1 LUT [ALL\]LUT Argum Modify the color look up table. Possibles arguments are - COLOR Load a default color table - WHITE Load a black and white color table (White background, black sources) - BLACK Load a black and white color table (Black background, white sources). - RGB , PHOTO and SHARP load three different LUTs used by the RGB command. - LUT Load the color table defined by the Hue array HUE. Saturation and Value (Brightness) of the HSV model are defined by the variables SATURATION and VALUE respectively. The HUE array can be obtained from the original LUT array using standard SIC mathematic functions. The number of actual colors used by OVERLAY on the display (i.e., the size of the arrays) is given by the SIC variable LUT_SIZE. - Any other : Red Green Blue values are read from the formatted file named "Argum". The default argument is LUT. A convenient value for the HUE array is LET HUE[I] = 256-I a "classical" color table from blue to red as used in AIPS for example. Color contours can be obtained using variations around the following command LET HUE[I] = 16*INT((LUT_SIZE-I)|16) and so on with the most funny functions you may invent. CAUTION : the HUE is a real number between 0 and 360.0 1 MOVIE ALL\MOVIE Start a movie procedure. The button control the movie mode - Left button : Stop movie command - Middle button : Image by image mode - Right button : Start movie Movie speed is controlled by pointer position (left fast, right slow). MOVIE mode must have been selected when mapping the image. 1 OVERLAY ALL\OVERLAY File [Format] Creates a copy of the current image and overlayed graphic in the specified format (only PostScript is available now, others are in development). Default file extension is .PS for PostScript files. The PostScript files may be sent to the LaserPrinter. 1 PAN [ALL]\PAN [Cx Cy] Move the zooming area to center it around the pixel (Cx,Cy) of the current image. The zooming factor is not changed. If no argument is given, use the mouse to point towards the center. 1 PLOT [ALL]\PLOT /GREG "Valid_GreG_Action" /PLANES List_of_Planes Computes the bitmap from the current image and plot it in the GreG window. The range specified by SET RANGE, and the scaling specified by SET SCALE are used. If neither the image, nor the scaling parameters have changed, the last bitmap is replotted without computations. The two options /GREG and /PLANES are restricted to the CUBE mode, where several planes of a data cube are plotted at the same time. They enable you to make a valid GreG action (BOX, RGM, GRID, etc...) for all planes (default) or a list of planes specified in the /PLANES option. The "Valid_GreG_Action" should be put between double quotes if the command is longer than one word. The List of Planes is the number(s) of planes for which the action should be undertaken, the syntax is the same as in the GREG2\LEVELS command: i1 i2 i3 to i4 by i5 i6 i7 i8 to i9 i10 .... Example: SET MODE CUBE IMAGE TOTO /PLANE 8 11 PLOT/GREG "BOX n n n" ! Will draw an unlabeled box around each plotted plane PLOT/GREG "AXIS XL/UNIT S"/PLANES 10 11 ! Will draw a labeled axis for the two lower boxes All graphics commands are replayed. 1 PSC_IRAS [ALL\]PSC_IRAS [Ra.#Dec.] [/OUTPUT Filename] [/LOOK Around] Find IRAS characteristics of point sources around the specified position. If no position is given, it calls the interactive cursor, and uses the returned coordinates to look for all IRAS sources around this point. The value Around (argument of option /LOOK) is the size of the search area in arc minutes (default 1). The result depends whether the full compact catalog is on line or not. - If not, the fluxes of the sources found in the search box are typed on the screen. - If it is on line, full information about the sources is either typed on the screen, or written on the file specified by the argument Filename of option /OUTPUT. In addition, a binary output file (whose name is PSCSUB.TAB) is produced. This binary file is suited for later processing by the Point Source Catalog software. The same files (formatted and binary) are used for multiple use of this command (unless the Filename is explicitely changed). 2 Format The listing produced by PSC_IRAS or the IRAS command has the following format : Right Ascension Sexagesimal notation in Hours Declination Sexagesimal notation in Degrees Lii (Degrees) Bii (Degrees) Semi-Major axis of position uncertainty ellipsis ( Arc Seconds Semi-Minor axis of position uncertainty ellipsis 95 confidence) Position Angle of the uncertainty ellipsis. (Degrees from North) Number of Hour confirmations Number of LRS spectra Type of LRS spectra Variability flag Discrepant flux flag Confusion flux flag Number of nearby hour confirmed point sources Number of nearby week confirmed point sources High source density bin flag CIRR1 Cirrus flag 1 CIRR2 Cirrus flag 2 CIRR3 100 micron sky brightness (MJy/Sr) Number of identifications Type of identifications For each flux (12, 25, 60 100 microns) Flux (Jy) Flux quality (1 upper limit, 2 poor, 3 good) Calibration uncertainty (%) Signal to noise ratio multiplied by 10 Point source correlation coefficient Number of hour confirmed small extended sources Number of week confirmed small extended sources Identifications (one line per identification) Name Catalog dependant informations Catalog name 1 REGRESSION REGRESSION Nmin [/RANGE [X Xmin Xmax] [Y Ymin Ymax]] Computes linear regressions in a image which is the correlation of two coincident images. The regression lines Y = A * X + B and X = A'* Y + B' are computed assuming the weight of any (X,Y) is the value of the pixel at X,Y. Nmin is the minimum pixel value considered as significant. 1 SPECTRUM SPECTRUM I [J [K]] Extract a spectrum from an image according to the following numbering : Spectrum (l) = Image (l,i,j,k) for a 4-dimensional image. The spectrum is loaded into the X,Y buffers of GreG. It can be processed later by the standard commands LIMITS, CONNECT, CURVE and so on. 1 SAVE [ALL\]SAVE File Saves the current displayed bitmap in a GILDAS image in Byte format. The resulting image can be redisplayed quickly using command FLASH. 1 SET [ALL\]SET Item Value Specify some OVERLAY parameters. Available parameters are : - SET RANGE AUTO or SET RANGE LOW_CUT HIGH_CUT specify the range of values to be displayed in the bitmap. - SET SCALING LINEAR or SET SCALING LOGARITHMIC or SET SCALING EQUALIZATION. specify the transformation applied to the image to obtain the bitmap. LINEAR is the fastest, EQUALIZATION the slowest. Moreover, EQUALIZATION scaling requires a large enough map with sufficient dynamic range. The EQUALISATION scaling tries to find the levels in the map that will give more or less the same number of pixels for each color value. The levels thus found are kept in the SIC#VARIABLE "LEVELS", and can be used to assign levels values to GreG (for the RGMAP command). - SET LEVELS nlev modifies the number of different values, i.e., colors (default:241) in which the image is scaled if SET SCALING EQUALIZATION has been chosen. useful for hardcopies on some plotters with few different grey or color levels, and if the image has less than 241 different values. SET SCALING LIN or LOG restores nlev to 241 (the LUT size); The number of levels used is accessible through the SIC#VARIABLE NLS - SET MODE CUBE or SET MODE IMAGE Specify in which mode you want to display the input data cube. IMAGE mode is used to display the cube plane by plane, in CUBE mode, OVERLAY tries to show as much planes as possible on the same image. See Command PLOT for details. CUBE mode is also used to make "movies". - SET X (or Y) INCREASING or DECREASING Specify whether image should be displayed using increasing or decreasing user coordinates along X or Y axis. 1 ZOOM [ALL\]ZOOM [X_blc Y_blc X_trc Y_trc] Display the area specified by its bottom left corner and top right corner in the ZOOM window. If no area is specified, use the mouse pointer to define the corners. The command is chained with a PAN command.