1 GREG1\ GREG1\ Language Summary AXIS : Draws an axis according to its name BOX : Makes a box labelled according to LIMITS and TICKSPACE COLUMN : Reads the data file CONNECT : Connects (X,Y) pairs with line segments CORNERS : Display corners of the plotting surface. CURVE : Connects (X,Y) pairs with a spline interpolation DRAW : Calls the interactive cursor or execute detailed command ERRORBAR : Draws error bars on (X,Y) pairs HISTOGRAM : Connects (X,Y) pairs as an histogram LABEL : Writes a string... according to options given LIMITS : Sets the limits of the plot (no args for auto) LOOK : Calls the cursor and executes a command when pressing key PENCIL : Selects and defines the pen attributes POINTS : Draws markers at the (X,Y) pairs RULE : Makes a grid by joining axis tickmarks SET : Modifies some basic parameters SHOW : Shows basic parameters (SORT) : Obsolete, see HELP SIC\SORT for a replacement TICKSPACE : Sets tick intervals for BOX or AXIS VALUES : Write the Y or Z values at the (X,Y) positions 2 NEWS Oct 1995: Separate text and marker orientation. Text orientation can now also be given in command LABEL and DRAW TEXT. See DRAW, LABEL, SET MARKER, SET ORIENTATION. Jul 1995: RGDATA enhanced: /SUBSET option even with /VARIABLE, simple- minded creating of a grid from X,Y,Z variables, etc. Jun 1995: "true" astronomical labelling. See BOX and SET SEXAGESIMAL. WEDGE command enhanced. Mar 1995: Pie charts possibility with ELLIPSE /ARC. Oct 1994: Support array variables as X \& Y coordinates in DRAW com- mand. CHARACTER array variables are also supported in DRAW TEXT command. Supports CHARACTER arrays for coordinates in the /USER AB- SO option. See DRAW. Sep 1994: Option /FILL to command BOX to have really nice colour plots. See BOX. 1 AXIS [GREG1\]AXIS NAME [A1 A2] [/TICK Orien Small Big] [/LOCATION X Y Len] [/LABEL Value [ONLY]] [/[NO]LOG] [/ABSOLUTE] [/UNIT Valid_Unit] [/[NO]BRIEF] Makes an axis labelled from A1 to A2 at location X, Y, length Len. The current ORIENTATION determines the angle of the axis. The axis scale is LINEAR or LOGARITHMIC according to the option /[NO]LOG. The tick orientation "Orien" may be IN or OUT or NONE with respect to the BOX. Tick spacing can be defined by Small and Big (see HELP TICKSPACE for more information on the tick spacing on linear and logar- ihmic axes). The orientation NONE cancels both ticks and labels. Labels for other "Orien" are drawn according to "Value", which may be N[one], P[arallel] or O[rthogonal] (to the axis). If option /LABEL has the sec- ond argument ONLY, only the labels of the axis are written, not the axis nor the ticks. This feature allows use of different pens for the labels and the axis. AXIS provides default values for all these parameters according to the axis NAME (XLow, XUp, YLeft, YRight) and the current values used by BOX. AXIS creates a graphic segment named "AXIS". 2 /ABSOLUTE The option /ABSOLUTE is used to write (RA,DEC) labels for EQUATORIAL system or (L,B) coordinates for GALACTIC system when a projection is ac- tive, i.e., both a PROJECTION and a SYSTEM are defined. RA (or L) is used for X-like axis, and DEC (or B) for Y-like axis. Note that this should be used only for small fields (size less than 0.2 Radians), and must be used only with the axes at the default position (i.e. no /LOCA- TION option). When SYSTEM is defined but the projection is NONE or has never been defined, the /ABSOLUTE option supports large fields (since PROJECTION NONE makes a non-conformal mapping anyway). The SET SEXAGESI- MAL command (see help) permits some mastering on how UNKNOWN or GALACTIC ABSOLUTE labels are written. See HELP TICKSPACE for more information on how to master the Tick spac- ing with the /ABSOLUTE or the /UNIT options. 2 /BRIEF The options /BRIEF and /NOBRIEF can be used to override the default tick labeling as ruled by the command G\SET AXIS. If /BRIEF is used, the tick labels are abbreviated, if possible. If /NOBRIEF is present, the tick labels are kept entire. The 2 options are exclusive. See HELP G\SET AXIS for details and examples. 2 /UNIT The option /UNIT is used to convert the axis coordinates to the de- sired unit, M for arc minutes, S for arc seconds, R for Radians. This option is valid only if a PROJECTION and a SYSTEM (EQUATORIAL or GALAC- TIC) are both defined. See HELP TICKSPACE for more information on how to master the Tick spacing with the /ABSOLUTE or the /UNIT options. 1 BOX [GREG1\]BOX [Arg1 [Arg2 [Arg3]]] [/ABSOLUTE] [/UNIT valid_unit] [/LABEL Pen] [/FILL pen_num] [/[NO]BRIEF [X|Y]] BOX puts axes around the plot region, labelling the lower and left ones. The first two arguments are used to modify the labelling of the lower and left axes respectively. They may take the values P for Parallel la- bels (default for X axis), O for Orthogonal labels (default for Y axis) or N for No labels. A third argument can be specified to indicate that the ticks are to be IN or OUT of the box, or not drawn at all (NONE). BOX creates a segment named "BOX". The option /LABEL is used to specify a different pen to use for axis la- belling. Creates a supplementary graphic segment "LABEL". The option "/FILL pen_num" will fill the inside of the box with the col- or of the pen pen_num. The last 16 pens (numbered 8-23) can receive ar- bitrary colors with the command LUT /PEN. Creates a supplementary graph- ic segment "FILL". BOX N N N makes a rectangle with the current pen, even if the pen is dashed. 2 /ABSOLUTE The option /ABSOLUTE is used to write (RA,DEC) labels for EQUATORIAL system or (L,B) coordinates for GALACTIC system when a projection is ac- tive, i.e., both a PROJECTION and a SYSTEM are defined. RA (or L) is used for X-like axis, and DEC (or B) for Y-like axis. Note that this should be used only for small fields (size less than 0.2 Radians), and must be used only with the axes at the default position (i.e. no /LOCA- TION option). When SYSTEM is defined but the projection is NONE or has never been defined, the /ABSOLUTE option supports large fields (since PROJECTION NONE makes a non-conformal mapping anyway). The SET SEXAGESI- MAL command (see help) permits some mastering on how UNKNOWN or GALACTIC ABSOLUTE labels are written. See HELP TICKSPACE for more information on how to master the Tick spac- ing with the /ABSOLUTE or the /UNIT options. 2 /BRIEF The options /BRIEF and /NOBRIEF can be used to override the default tick labeling as ruled by the command G\SET AXIS. If /BRIEF is used, the tick labels are abbreviated, if possible. If /NOBRIEF is present, the tick labels are kept entire. If the keyword X or Y is used as argument of the options, it indicates to apply the corresponding mode only to the designated axis. The options /BRIEF and /NOBRIEF are compatible as long as the same axis is not designated twice. See HELP G\SET AXIS for details and examples. 2 /UNIT The option /UNIT is used to convert the axis coordinates to the de- sired unit, M for arc minutes, S for arc seconds, R for Radians. This option is valid only if a PROJECTION and a SYSTEM (EQUATORIAL or GALAC- TIC) are both defined. See HELP TICKSPACE for more information on how to master the Tick spacing with the /ABSOLUTE or the /UNIT options. 1 COLUMN [GREG1\]COLUMN [X Nx] [Y Ny] [Z Nz] [/FILE File_Name] [/LINES L1 [L2]] [/TABLE Table_Name] [/COMMENT "Separator"] [/CLOSE] This command will read X data from column Nx of the current file, Y data from column Ny and Z data from column Nz of the current (or specified) input file or binary table. Any combination of any of three X,Y,Z items is valid in any order, provided the column number immediately follows the column descriptor. The X and Y arrays contain respectively the X and Y coordinates of points to be plotted. The Z array is an additional buffer which is used for ERRORBARS, for RANDOM maps and so on. 2 /COMMENT [GREG1\]COLUMN /COMMENT "Separator" Specify which character is used to indicate the beginning of a comment line in the input file. "Separator" is a single character; typical val- ues are "!", ";", "#", although any single character can be specified. The default is set by command SET COMMENT (default "!"). 2 /CLOSE [GREG1\]COLUMN /CLOSE Closes the file previously opened by command COLUMN /FILE, or frees mem- ory allocated for the table previously opened with command COLUMN /TA- BLE, if any. 2 /FILE [GREG1\]COLUMN /FILE File_Name Indicates in which formatted (list-directed free format) file the data are to be read. If not given, the last input file or table is used. There is no more limit on the number of lines that can be read from a formatted file. However, use wisely this command on extremely large for- matted file because the memory allocated by the COLUMN command is never released before program exit. 2 /LINES [GREG1\]COLUMN /LINES L1 [L2] limits the range of lines read in the input file or table. L1 and L2 re- fer to absolute line numbers. Since comment lines are ignored, number of read lines is at most L2-L1+1, and can be 0 if all lines were comments. This option is useful to avoid non-data lines, or to read by pieces a formatted file which is too long for the column buffers. L1 and L2 are reinitialized for each new input file or table. L2 defaults to end of file if not specified. 2 /TABLE [GREG1\]COLUMN /TABLE Table_Name Indicates that the columns are to be read in a "Table" at the GILDAS format. If not given, the last input file or table is used. "Table" for- mat is typically 100 times more efficient used than the formatted file format. 1 CONNECT [GREG1\]CONNECT [Array_X Array_Y] [/BLANKING Bval Eval] [/FILL] CONNECT draws line segments connecting the coordinates read by COLUMN X and Y, or stored in the variables Array_X Array_Y. The current pencil with its dashed pattern is used. CONNECT uses the current blanking values, which can be overridden by the /BLANKING option. Hence, it does not connect with data points so that abs(Y(i)-Bval) <= Eval. Eval negative means no blanking value, and Bval and Eval values default to those specified in SET BLANKING. 2 /FILL [GREG1\]CONNECT [Array_X Array_Y] [/FILL] The /FILL option indicates to fill the connected line. Blanking is ir- relevant. The connected line is closed by linking together the first and last point, then filled with the colour of the current pen. Use with caution on complex shapes. 1 CORNERS [GREG1\]CORNERS Displays angles in corners indicating the limits of the plotting surface. 1 CURVE [GREG1\]CURVE [Array_X Array_Y] [/ACCURACY A] [/VARIABLE V [Ar- ray_V]] [/PERIODIC] [/BLANKING Bval Eval] Builds the spline interpolation of the (X,Y) pairs read by COLUMN, or stored in the variables Array_X Array_Y, using the selected algorithm and options. The current pen with its dashed pattern is used. Presently the only algorithm available is CUBIC_SPLINE. By default, the command assumes that a curve Y=f(X) is to be plotted ; this can be changed using options to specify the kind of curve to be plotted. 2 /ACCURACY [GREG1\]CURVE /ACCURACY A Controls the accuracy of the spline interpolation. The argument is the desired accuracy (in paper units, i.e. centimeters) and should be set to the plotter resolution. The default value is defined using the SET ACCU- RACY command. 2 /BLANKING [GREG1\]CURVE /BLANKING Bval Eval Does not uses data points such that abs(Y(i)-Bval) < Eval. These points act as separators. Eval negative means no blanking value. Bval and Eval values default to those specified in SET BLANKING. 2 /PERIODIC [GREG1\]CURVE /PERIODIC Specifies that the curve is periodic (and currently closed also). If /VARIABLE X, it expects that y(1)=y(NXY) ; if /VARIABLE Y, that x(1)=x(NXY) ; and in the case of a parametric curve, that x(1)=x(NXY) and y(1)=y(NXY). 2 /VARIABLE [GREG1\]CURVE /VARIABLE V [Array_V] Selects the the interpolation variable V, which may be - X To plot a function Y=F(X) (Default) - Y To plot a function X=F(Y) - Z [Array_V] To plot a curve with an explicit parametrization using the Z array, or the array Array_V if this second argument is present. - POLYGONAL_LENGTH To plot a curve using the polygonal length of the curve as parametrization. It is fast and of general use. - CURVILINEAR_LENGTH Refined and slow version of the parametrization in POLYGONAL_LENGTH. - NUMBERING The parameter is the numbering of points. It is only appropriate if the numbering reflects a reasonable parametriza- tion of the curve. 1 DRAW [GREG1\]DRAW Argument Xc Yc [/CLIP] [/BOX N] [/CHARACTER N] [/USER [code]] This is a powerful command which allows you to make drawings without da- ta either by specifying coordinates (Xc,Yc) and action desired (Argu- ment), or by interactive use of a cursor. The cursor is obtained in the current active window if Xc and Yc are omitted, and the appropriate action is then specified by keys typed at the keyboard: R is for RELOCATE, L for LINE, M for MARKER, A for ARROW, T for TEXT. In addition, C works like T, but prompts for the centering parameter in addition to the text. D can be used to DELETE the last op- eration, and has no action on the operations which were plotted previ- ously to the current DRAW command. E exits from the cursor routine. ^C will exit AND generate an error, which can be trapped (useful to regain control inside of forever SIC loops calling the interactive cursor re- peatedly). Other keys gives you the cursor coordinates (in the current angular unit when a projection is defined), except that keys `0' `1' `2' and `3' tem- porarily (i.e., as long one does not exit from cursor mode) change the current angular unit in which the cursor coordinates are returned. For X11 displays, you may use the mouse buttons for the commands R (left mouse button), L (middle mouse button), and E (right mouse button). The complete command is written to the LOG_FILE so that you can replay it easily. The option allows you to supersede the default value of the coordinate system defined by SET COORDINATE or to keep clipping. The code suboption in the /USER option, if present, can be any of `SECONDS', `MINUTES', `DEGREES', `RADIANS' (in which case the Xc and Yc coordinates are taken to be in the corresponding unit) or `ABSOLUTE' (in which case Xc and Yc are taken as absolute coordinates, usually exprimed in sexa- gesimal format). The presence of the code suboption is valid only if a PROJECTION and a SYSTEM (EQUATORIAL or GALACTIC) are both defined. When using the explicit form, Xc and Yc may be equal to * to use the current pen position. Any "realistic" combination of literal values, 0-d and 1-dimensional variables is accepted for that command. For example, DRAW MARKER A B /USER MINUTES will plot markers at each location given by the two arrays A and B (pro- vided they are of the same size). A and B must be CHARACTER arrays in the case where the "/USER ABSOLUTE" option is used. 2 ARROW [GREG1\]DRAW ARROW Xc Yc Draw an arrow from current location to given location. The arrow size is governed by EXPAND and MARKER size. Cursor form A. 2 LINE [GREG1\]DRAW LINE Xc Yc Move pen down to given location (Xc,Yc). The line will be clipped in the box only if the /CLIP option is present. Cursor form L. 2 MARKER [GREG1\]DRAW MARKER Xc Yc Draw a graphic marker at given location (Xc,Yc). Current marker style and size is used. Cursor form M. 2 RELOCATE [GREG1\]DRAW RELOCATE Xc Yc Move pen up to given location (Xc,Yc). Cursor form R. 2 TEXT [GREG1\]DRAW TEXT Xc Yc "Text" [N [Orien]] Draw a text at location (Xc,Yc) according to the centering parameter N, or to the current centering parameter if N is not specified. Cursor form T, or C to be prompted for the centering. The orientation angle of the text (in degrees, counterclockwise) can be specified after the centering parameter; otherwise the current orientation defined by SET ORIENTATION is used. 2 VALUE [GREG1\]DRAW VALUE Xc Yc Inquires the map value at the location (Xc,Yc). A regular grid array must be present to use this, (Xc,Yc) must be within the Regular Grid ar- ray limits; otherwise the command is ignored. Cursor form V. 2 /BOX [GREG1\]DRAW [Action Xc Yc] /BOX N Specifies that coordinates Xc Yc are physical units relative to point number N of the current BOX. The 9 most remarkable points of the box (corners, middle of the sides, and box center) are numbered according to a VT100 numeric keypad notation (see HELP GREG1\LABEL /CENTERING ). 2 /CHARACTER [GREG1\]DRAW [Action Xc Yc] /CHARACTER N Specifies that coordinates Xc Yc are units of character size, and rela- tive to point number N of the current BOX. The 9 most remarkable points of the box (corners, middle of the sides, and box center) are numbered according to a VT100 numeric keypad notation (see HELP GREG1\LABEL /CEN- TERING ). 2 /CLIP [GREG1\]DRAW [Action Xc Yc] /CLIP Keeps clipping in the box for all drawing actions (except for labels which are never clipped). 2 /USER [GREG1\]DRAW [Action Xc Yc] /USER Specifies that coordinates are user coordinates. 1 ERRORBAR [GREG1\]ERRORBAR Argument [Array_X Array_Y Array_Z [Orientation]] This command draws error bars on all (X,Y) points (read by COLUMN X and Y, or specified in Array_X Array_Y) of length read by COLUMN Z or speci- fied by Array_Z. Argument may be +X X -X +Y Y or -Y. Symmetric error- bars are drawn if you do not specify the sign, while only the errorbar of the given sign is drawn if you do so. This allows independent error- bars in opposite directions. The size of the line at the end of the er- rorbar is the Marker size and can therefore be adjusted with SET MARKER. Errorbars with arbitrary orientation can be obtained by specifying code +O, O or -O. The orientation (in degrees) is then either read from a fourth array if one is specified on the command line, or otherwise taken from the current marker orientation (as specified in SET ORIENTATION). 1 HISTOGRAM [GREG1\]HISTOGRAM [Array_X Array_Y] [/BASE [Ybase]] [/BLANKING Bval Eval] [/FILL [Icolor]] [/HATCH [Ipen] [Angle] [Separ] [Phase]] Connects the coordinates read by COLUMN X and Y, or stored in the vari- ables Array_X Array_Y as a histogram. The /BASE option specifies a "true" histogram, connected to a base level (Default Ybase=0). The /BLANKING option will supersede the current blanking values (as defined by SET BLANKING command) so that data points with abs(Y(i)-Bval) < Eval are not plotted. Eval negative means no blanking value. Filled Histogram is created by the options /FILL + /BASE. 2 /FILL [GREG1\]HISTOGRAM [Array_X Array_Y] /FILL [Icol] [/BASE Ybase] The /FILL option indicates to fill the histogram with the colour of the current pen. Blanking is handled as for other histograms. Usually needs to be done in conjunction with the BASE option to properly fill the his- togram. Icol is the number (0-23) of the color used to fill. The colors of the last 16 pens (8-23) can be changed by the user (See HELP LUT /PEN). 2 /HATCH [GREG1\]HISTOGRAM [Array_X Array_Y] /HATCH [Ipen] [Angle] [Separ] [Phase] [/FILL Icolor] [/BASE Ybase] Fill the histogram with parallel lines. The pen (default current), the line orientation in degrees (default 45), separation in physical units (default 0.25 cm), and phase between 0. and 1. (default 0.) can be cus- tomized. The phase indicate to displace the hatch lines by this fraction of the separation from a fixed reference. The histogram is filled down to the base Ybase (default 0.). The option /FILL can be combined with /HATCH. The histogram contour is not drawn, if desired this must be done with other call(s) to the command. 1 LABEL [GREG1\]LABEL "Character String" [Orientation] [/APPEND] [/CENTER- ING N] [/X [Offset]] [/Y [Offset]] Writes the string Character String (included between double quotes) at current pen position or location specified by option, and with current or requested centering. The label is written according to the current or specified Orientation and EXPAND factors. Within a string, the char- acter "\" is an escape character and causes the following action : \\X - set mode X \X - set mode X for next char \N - Default character set \1 - Simplex character set \2 - Duplex character set \R - Roman font \G - Greek font \S - Script font \I - toggle italics \U - superscript \D - subscript \B - backspace over previous char 2 /APPEND [GREG1\]LABEL /APPEND Append the label at current pen location. This corresponds to /CENTER- ING 6. 2 /CENTERING [GREG1\]LABEL /CENTERING N The label is oriented with respect to the current location according to the argument N which can be 1 - 9 for : right center left justified label above 7 8 9 centered 4 5 6 below 1 2 3 These conventions follow the standard numeric keypads notation. 2 /X [GREG1\]LABEL /X [Offset] Put the label centered below the X axis made by BOX. Offset is an op- tional argument to indicate the separation between the label and the ax- is (in character size, default set by SET LABEL). 2 /Y [GREG1\]LABEL /Y [Offset] Put the label centered left of the Y axis made by BOX. Offset is an op- tional argument to indicate the separation between the label and the ax- is (in character size, default set by SET LABEL). 1 LIMITS [GREG1\]LIMITS [X1 X2 Y1 Y2 [Unit]] [/XLOG] [/YLOG] [/RGDATA] [/BLANKING Bval Eval] [/REVERSE [X] [Y]] [/VARIABLES Array_X Array_Y] Sets the coordinates of the plot region. The limits are the user coordi- nates of the BOX corners, and in conjunction with the BOX_LOCATION, specifies the conversion formula between USER and PLOT coordinates. If LIMITS has no arguments, it will compute automatic limits. The data from the most recent COLUMN X and Y are used to set the limits, except if the /RGDATA option is present, in which case the last read regular grid map is used. Some special characters are allowed instead of numerical values for the limits : * Compute automatic limit for this argument < Compute automatic limit for this argument, and take the minimum of this value and the precedent limit. > Same as above, but take the maximum. = Keep the precedent value for this limit. An additional argument can be used when a projection and a system are defined. It may take values - RADIAN : The values are assumed to be normal projected coordinates from the projection center. - SECOND, MINUTE or DEGREE : The values are converted from the speci- fied angular unit to radians. They still represent offsets from the projection center. - ABSOLUTE : The values are assumed to be absolute coordinates on the sphere. APPROXIMATE corresponding projected coordinates are computed from these values (the projected coordinates are necessarily approx- imate since in general e.g. the upper left and lower left corner of the box correspond to different absolute Right ascension for Equato- rial system). The default value is the current angle unit as defined by SET ANGLE. 2 /BLANKING [GREG1\]LIMITS [Args . . .] /BLANKING Bval Eval Does not use data points such that abs(Y(i)-Bval) < Eval. These points act as separators. Eval negative means no blanking value. Bval and Eval values default to those specified in SET BLANKING. Note that blanking applies to the intensities (Y) array only, but that the blanked values in the Y array are used as a mask to compute the X limits. This option can not be used with /RGDATA. 2 /REVERSE [GREG1\]LIMITS [Args . . .] /REVERSE [X] [Y] Exchange the left and right limits for X axis, and/or top and bottom limits for Y axis. 2 /RGDATA [GREG1\]LIMITS [Args . . .] /RGDATA Specifies that the current Regular Grid array should be used to compute the (non-specified) limits, instead of the current column arrays. Loga- rithmic conversion formulae are not allowed in this case. The /BLANKING and /VARIABLES options are incompatible with /RGDATA. 2 /VARIABLES [GREG1\]LIMITS [Args . . .] /VARIABLES Array_X Array_Y Use SIC variables Array_X Array_Y to compute the limits, instead of the X and Y buffers. Cannot be used with the /RGDATA option. 2 /XLOG [GREG1\]LIMITS [Args . . .] /XLOG Specifies that the X conversion formula should be logarithmic. Cannot be used with the /RGDATA option. 2 /YLOG [GREG1\]LIMITS [Args . . .] /YLOG Specifies that the Y conversion formula should be logarithmic. Cannot be used with the /RGDATA option. 1 LOOK [GREG1\]LOOK "Command" Calls the cursor, and executes the specified command each time it is pressed. The command can be a procedure (e.g. @my_look) and can test the pressed character which is added at the end as first argument. Usual exit keys ("E", right-clic, ...) or "*" can be used to exit. For exam- ple, a calling session may look like: GREG-PROMPT> LOOK "SAY You pressed " You pressed Q GREG-PROMPT> if "Q" and then "E" have been pressed. 1 PENCIL [GREG1\]PENCIL [N] [/COLOUR C] [/DASHED D] [/WEIGHT W] [/DEFAULT] Selects virtual pen N and defines its attributes in terms of colour (if supported by the device), dashed pattern and weight (thickness). Up to 16 pens can be defined (0-15). Most plotting commands uses the current pen. The major exception is RGMAP which uses the pen 0 (solid and fore- ground color by default) and 15 (dotted and blue by default). Some com- mands also ignore the dashed patterns, in particular all labels and the BOX command. - The dashed pattern D must be in range 1 to 7, 1 means solid lines. - The weight factor W must be in range 1 to 5. - The colour index C is an integer in range -1 to 23. The colors 0 to 7 are FIXED, the last 16 are user-definable, the color -1 means in- version. See the topic COLORS for more information on pen colors. PENCIL N /DEFAULT reset default attributes to Pen number N. PENCIL /DE- FAULT reset default attributes for all Pens, as defined at program ini- tialization. 2 COLORS There are 25 colors available for PENS. Colors -1, 0 and 7 are SPE- CIAL, colors 1 to 6 are FIXED (named colors or their equivalent shade of grey on grayscale terminals). The last 16 are user-defined. Color 0 (the default for the default PEN 0) is ALWAYS the foreground color (i.e., always visible whatever the background color of the graphic window is), and becomes BLACK on the paper hardcopy. Color 7 is ALWAYS the background color, useful for text written on an grey-scale image for example. Colors 1 to 6 are defined as follows for a standard display with suffi- cient colors available in its colormap: "red","green","blue","cyan","yellow" and "magenta" For grey-scale displays, it becomes: "grey42","grey70","grey14","grey28","grey56" and "grey84" This may vary depending on the number of available colors on your dis- play. The last 16 colors are user-definable (see HELP LUT) and correspond to the 16 'FILL PENS' used as fill colors in various commands, like RGMAP /GREY or POLYGON /FILL. Finally, the color -1 is negative, which means it will have an inverse color of what is behind. It is useful to draw segments which are always visible, whatever the context. This special color is available only un- der X and PNG devices. For the others, the foreground color (0) is used. 1 POINTS [GREG1\]POINTS [Xarray Yarray] [/BLANKING Bval [Eval]] [/SIZE Zvalue [Zarray [Exponent]]] [/MARKER SidesArray StyleArray] Makes points of the current style (MARKER), size (MARKER and EXPAND), and orientation (ORIENTATION) at the X and Y coordinates read by COLUMN, or in the variables Xarray and Yarray. With the option /SIZE, followed by a real value Zvalue, POINTS will draw markers of sizes governed by the values of the Z array (or of the Zarray if specified). Points with Z value equal to Zvalue will have a marker of size the current marker size. All other markers will have an AREA pro- portional to the Z value at each point (i.e. marker radius at X(i) Y(i) proportional to the square root of Z(i); this power law exponent can be changed by specifying an additional argument to option /SIZE). If Zval- ue is equal to zero, the program uses the maximum absolute value of the Z array instead. The /BLANKING option can be used to override the current blanking be- haviour, as defined by SET BLANKING command. If Eval (defined by /BLANK- ING or SET BLANKING) is null or positive, blanking is enabled. If /SIZE is used, blanking applies to the Z (or Zarray) values, e.g. in a context of a (coordinate,coordinate,intensity) map. If /SIZE is not used, blank- ing applies to the Y (or Yarray) values, e.g. in a context of a (abscis- sa,intensity) profile. The /MARKER option can be used to specify a different marker sidedness and style for each data point. 1 RULE [GREG1\]RULE [X] [Y] [/MAJOR] [/MINOR] Without an argument, or with both X and Y arguments, RULE makes a grid within the BOX using the current pen. Major or minor ticks or both are selected according to the options. With the argument X or Y, the grid is restricted to X or Y ticks respectively. The /MAJOR and /MINOR op- tions can be combined in the same command. 2 /MAJOR [GREG1\]RULE [X] [Y] /MAJOR Makes a grid at major ticks (This is the default if no option is given). 2 /MINOR [GREG1\]RULE [X] [Y] /MINOR Makes a grid at minor ticks. 1 SET [GREG1\]SET Argument [Value [...]] [/DEFAULT] Specify or reset some default value for a parameter used by GreG. These values may sometimes be overridden for a single command by the appropri- ate option (e.g. /BLANKING and SET BLANKING). SET Argument /DEFAULT re- set the default values for the given key. SET /DEFAULT reset all default values of SET including the FONT and the PLOT_PAGE ; thus the plot cleared. Use PENCIL /DEFAULT to reset the PEN- CIL definitions, and TICKSPACE 0 0 0 0 to reset tick spacing parameters. You can use GREG1\SHOW to see the current value of one or all items. 2 ANGLE_UNIT [GREG1\]SET ANGLE_UNIT D Sets the angle unit for the projection limits. This will become effec- tive only when a projection is effective, and only affects the way lim- its are given and labels written (not internally stored). D may have the values SECOND, MINUTE, DEGREE, RADIAN. 2 ACCURACY [GREG1\]SET ACCURACY D Sets the default accuracy (in paper units, i.e. centimeters) used by the command GREG1\CURVE. It should be set to the plotter resolution, and must be in range 0.0001 to 1. Default value is 0.01. 2 AXIS [GREG1\]SET AXIS EXPO|NOEXPO [X|Y|Z] [GREG1\]SET AXIS BRIEF|NOBRIEF [XDECIMAL|YDECIMAL|XSEXAGESIMAL|YSEX- AGESIMAL] SET AXIS EXPO forces the use of exponential notation for tick la- bels. By default (NOEXPO mode), Greg labels the ticks with plain integers (if abs(value)>=1) or decimal floats (if abs(value)<1) as long as the label is 6 characters or less. For larger labels, Greg switches to the expo- nential notation. This default mode can lead to inhomogeneous labels, some as plain inte- gers, others in exponential format. The mode EXPO forces the use the latter format for all labels. The labelling rule can be customized for X, Y, or Z (intensities i.e. wedge labelling). With no argument, the command applies to those three. The plain integer/decimal versus exponential formats apply to decimal and logarithmic axes. Sexagesimal axes have their own labelling rules. SET AXIS BRIEF|NOBRIEF [XDECIMAL|YDECIMAL|XSEXAGESIMAL|YSEXAGESIMAL] The BRIEF keyword indicates to the commands G\AXIS and G\BOX to abbrevi- ate the major tick labels, if possible. Abbreviating means dropping off leading digits which are common to all tick labels of one axis, in order to make the relevant information (the variable digits) easier to read. This is particularly suited to axes showing a small range of values around a large one. This can also help saving place depending on the ax- is and its tick labels orientation. Note that the first tick label is kept entire while the other are abbreviated, and sign is preserved. The NOBRIEF keyword indicate not to attempt the abbreviation. A complementary argument can indicate which kind of axes should be af- fected. X and Y refer respectively to horizontal and vertical axes. The suffix DECIMAL refers to standard linear numbering, while SEXAGESIMAL refers to sexagesimal notations of any kind. Logarithmic axes are not affected. By default the command modifies the behavior of both axes in both supported modes. Defaults are: XDECIMAL NOBRIEF YDECIMAL NOBRIEF XSEXAGESIMAL BRIEF YSEXAGESIMAL NOBRIEF Here are several examples for axes with 3 major ticks: * NOBRIEF mode: 123456 123457 123458 -123456.7 -123456.75 -123456.8 1000 2000 3000 -1 0 1 12h34m56s 12h34m57s 12h34m58s 12h34m00s 12h36m00s 12h38m00s * Same in BRIEF mode: 123546 7 8 -123546.7 -.75 -.8 1000 2000 3000 -1 0 1 12h34m56s 57s 58s 12h34m00s 36m00s 38m00s 2 BLANKING [GREG1\]SET BLANKING Bval Eval Define a blanking value Bval with tolerance Eval. Default is no blanking (i.e. Eval negative). The blanking is used by most curve plotting com- mands such as CURVE, CONNECT, POINTS to ignore data points which verify ABS(Y-Bval) less or equal to Eval. The blanking value is also used for contours (RGMAP), to avoid plotting contours in pixels whose value veri- fy the same relation as above. And finally, some commands require a blanking value to attribute when they are unable to define a real val- ue ; this include RANDOM and MASK. 2 BOX_LOCATION [GREG1\]SET BOX_LOCATION Argument_List Define the position of the box. The argument list specifies various op- tions for the box position : - PORTRAIT Define a default Portrait oriented box - LANDSCAPE Define a default Landscape oriented box - SQUARE Define a square box - MATCH [Gx1 Gy1 [Ratio]] Define a box which matches the ratio of the physical units. By default, the bottom left corner is placed at the default position for the current plot page, but can be moved by specifying arguments Gx1 and Gy1. The box size is adjusted such that the box occupies as much space as possible within the default box position for the current plot page type. Ratio is an additional ar- guments which indicates a scaling factor for the Y axis. WARNING : The box is computed from the current limits, and will not change if you compute new limits. - Gx1 Gx2 Gy1 Gy2 Defines the positions of all box corners in physi- cal units. The default is LANDSCAPE, PORTRAIT or the default VIEWPORT according to the current PLOT_PAGE type. 2 CENTERING [GREG1\]SET CENTERING N Sets the centering option. Default is 0, which means automatic centering according to the position relative to the box. 2 CHARACTER [GREG1\]SET CHARACTER S Sets the character size to S physical units. Default is 0.6 . 2 COMMENT [GREG1\]SET COMMENT "Separator" Specify which character is used to indicate the beginning of a comment line in formatted input files for command COLUMN. "Separator" is a sin- gle character; typical values are "!", ";", "#", although any single character can be specified. The default is "!". 2 COORDINATES [GREG1\]SET COORDINATES [System [N]] Sets the coordinate system for DRAW. The system may be BOX, CHARACTER or USER. If BOX or CHARACTER, N can be used to specify the point of the box to which the units refer. Nine points are available, following a stan- dard VT100 keypad disposition (see HELP GREG1\LABEL /CENTERING ). N may be 0. In this case, the nearest point will be used when making annota- tions with the cursor, and point 1 will be used in explicit form. The default is BOX 0. 2 DECIMAL [GREG1\]SET DECIMAL [X] [Y] Specify that labelling of X or Y axis is with a decimal field (default). Used to revert from sexagesimal labelling (See HELP SET SEXAGESIMAL). 2 EXPAND [GREG1\]SET EXPAND E Expands all characters or markers by a factor E. Default is 1. 2 FONT [GREG1\]SET FONT F Defines the character font used. F may be SIMPLEX (default) or DUPLEX, which is nicer but substantially slower, and should be reserved to pub- lication quality plots. Default is SIMPLEX. 2 LABEL [GREG1\]SET LABEL X|Y [Offset] Defines the distance between the label (legend drawn by command G\LABEL) and the corresponding axis. The default is 2 character sizes in X, and 6 in Y. This sometimes require adjustment for publication quality plots. See also command LABEL /X [Offset] and /Y [Offset]. 2 MARKER [GREG1\]SET MARKER Nsides Mstyle Size Orien Sets the marker type to a polygon of Nsides, of style Mstyle (0-3) and size Size physical units. Nsides=0,1 Dots ; Nsides=2 Bar ; Nsides=3 Triangle ... Mstyle=0 Convex polygon ; Mstyle=1 Vertex connected ; Mstyle=2 Starred polygon, and Mstyle=3 Filled polygon (Only for Nsides >= 3) The default is Nsides=0 Mstyle=0 Size=0 and Orientation 0 (Points, opti- mized algorithm). The Orientation is used to plot the marker (e.g. Hori- zontal bar for MARKER 2 0 * 0.0, and vertical bar for same marker MARKER 2 0 * 90.0). A * instead of a numerical value indicate to keep the last value. 2 ORIENTATION [GREG1\]SET ORIENTATION T [M] Set orientation of text to T degrees and that of markers to M degrees (M = T if not specified). The text orientation also controls the orienta- tion of axes. Default is 0.0 (horizontal). Text orientation can also be controlled by command DRAW TEXT, and Marker orientation by command SET MARKER. 2 PLOT_PAGE [GREG1\]SET PLOT_PAGE X Y Sets the physical size of plot page. One can use "PORTRAIT" and "LAND- SCAPE" for A4 format with adequate orientation, and square will give a 30 by 30 cm plot page. Default is LANDSCAPE (A4 30 by 21 cm). 2 SEXAGESIMAL [GREG1\]SET SEXAGESIMAL [X [Nx]] [Y [[Ny]] Set X axis labelling in sexagesimal notation with Nx decimals (resp. Y). The default (Nx=1, Ny=0 and no sexagesimal notation) is nearly always perfect for everybody. So, this command is used for two restricted purposes: - to enable sexagesimal notation of axis when a projection is in use, the system is GALACTIC and the /ABSOLUTE option is required (for EQUATORIAL systems, the sexagesimal notation is always used in this case, but the default for GALACTIC system is a decimal representa- tion of degrees). - to specify the number of decimals when using ABSOLUTE labelling (see BOX /ABSOLUTE or AXIS /ABSOLUTE). Note that, when a realistic tick spacing is required by the user or (the default) GreG computes this spacing automatically, labelled tickmarks will fall on rounded values, so no decimals will appear (unless the field of view is smaller than a few arc seconds). 2 SYSTEM [GREG1\]SET SYSTEM Name [Epoch] Specify the coordinate system used in case of projection. The name can be UNKNOWN, GALACTIC or EQUATORIAL (default epoch is 2000.0 if not pro- vided). The SYSTEM affects the projection definitions (in particular the GRID command) and coordinates sent back by the cursor (different formats are used for each system). 2 TICKSIZE [GREG1\]SET TICKSIZE Major [Minor] Sets the major tick size to Major (in physical units). The default value is 0.3. Minor tick size can also be set. If absent, Minor is half the Major tick size value. 2 VIEWPORT [GREG1\]SET VIEWPORT Px1 Px2 Py1 Py2 Defines the position of the box in terms of fractions of the plot page size in X and Y. Default is 0.150 0.925 0.125 0.925 . 1 SHOW [GREG1\]SHOW Item - SHOW lists the current value of the associated parame- ter(s). - SHOW ALL lists the values of all the SET parameters. - SHOW PEN lists the current pen definitions (use the PENCIL command itself for informations on the active pen alone). - SHOW PROJECTION lists the current projection used. - SHOW [WHERE|LIMITS] [DEGREE|MINUTE|SECOND|RADIAN|ABSOLUTE] shows the current pen location and plot region limits in User and Plot coordi- nates. The second argument modifies the angular units in which the user's values are displayed, when a projection is enabled of course (default current angle unit). - SHOW without arguments is a synonym of SHOW WHERE. 1 SORT [GREG1\]SORT Key OBSOLETE COMMAND. See HELP SIC\SORT for a replacement. Sorts the current X-Y-Z buffers according to the one given as Key name, which will be in ascending order after the sorting. It may be useful if you want to plot a curve, but have data disordered. 1 TICKSPACE [GREG1\]TICKSPACE SmallX BigX SmallY BigY Sets tick intervals (in User coordinates) for BOX or default intervals for AXIS. SmallX refers to the interval between small tick marks on the X axis, BigX refers to the interval between large ticks, etc. If Big is 0, the axis routine will supply its own Big intervals according to the label limits and use your Small value if non zero. To restore fully au- tomatic ticking, set Small and Big equal to 0. To suppress small ticks, specify equal values for Small and Big. The Small and Big values are meaningless for LOGarithmic axes, which us- es their own conventions. If two major ticks are separated: - by one decade, the minor ticks are at all unitary values of the decade, - by two decades, the minor ticks are at values 2, 5, 10, 20, and 50, - by three or more decades, the minor ticks are at (some of) the in- termediate decades. When using the /ABSOLUTE or /UNIT option for axis-drawing commands, one has to keep in mind that Small and Big (if not 0) should be expressed: - in seconds of arc for declination or galactic (sexagesimal notation) axis, /ABSOLUTE option (one can usually multiply by 3600 the desired tick spacing) - in seconds of time for right ascension axis, /ABSOLUTE option (mul- tiply by 12) - in seconds, minutes or degrees when option /UNIT [SECOND|MINUTE|DE- GREE] is used. Thus in the case of a user-defined tick spacing, TICKSPACE must be rede- fined before using another option. 1 VALUES [GREG1\]VALUES [Array_X Array_Y [Array_Z]] [/BLANKING Bval [Eval]] With no argument, VALUES writes (in the shortest possible format) the values of the Z array at the (X,Y) positions in the box. Three X Y Z ar- rays can be specified explicitly instead, e.g. in a context of a (coor- dinate,coordinate,intensity) map. With two X Y arguments, VALUES writes the values of the Y array at the (X,Y) positions, e.g. in a context of a (abscissa,intensity) profile. The current character size, expansion factor and fonts are used. Only points inside the current box are written, but the labels may still span over the box itself. Blanking (if any) applies to the plotted values (Y or Z if 2 or 3 argu- ments resp.). Global blanking values (SET BLANKING) can be overriden with the option /BLANKING. 1 ENDOFHELP