When DISP1D is one, a 1D graphic window call "1D Spectrum" is displayed on screen, 1D buffer will be displayed in this window . 2D will be displayed as density colour maps in a square window call "2D window" when DISP2D is 1. In 3D mode, planes extracted from the 3D data-sets will be displayed as 2D. Setting these contexts to 0 actually closes the associated window.
The size of the created windows with the DISP2D command, is hard-wired and cannot be modified.
The display is refreshed at only the end of each command line; you can thus avoid useless display of intermediate computation by putting all the related commands on one line. 2D are displayed in density mode. The density mode consists of a colour coding of the value of the points. 64 colours are used, distributed with a constant interval on positive and negative values. Values around zero are coded in black.
These contexts characterise the state of the display and the plotting.
The display is computed at the end of the command line. Some point may be skipped when displaying large spectra (typically greater than 4k in 1D, and larger than 512x512 in 2D) but not for plotting. The vertical size of the display is defined by the SCALE context. The display depends also on the ITYPE value; imaginary points are nor displayed.
The scale is computed such that for SCALE=1, the larger point of the spectrum is full-screen. The value of this larger point is held in the ABSMAX context. ABSMAX is recomputed at display time whenever the data actually changed, however it is not recomputed when it is not needed and you can force the computation of ABSMAX by putting its value to 0. The scale being relative, ABSMAX can be modified to compute absolute display and plot by forcing its value to any pre-defined value. This value will not be overridden as long as the data are not actually changed.
To make this long story short, one can say that the point with the value ABSMAX/SCALE will be displayed full screen.
SIGN determined, in 2D or 3D whether only positive points, only negative points or both will displayed.
VHEIGHT is the level to which the zero level will be plotted in 1D display. Unit is in %, 0 will draw at the bottom of the screen/page, 1 at the top. Standard value is 0.3 (30%).
CLEAR context determines if each display will be drawn on the top of the previous one (0 mode) or if the window will be cleared before drawing (1 mode - default mode).
A second display mode is available in 2D which is a contour plot mode that is activated with the command CDISP2D. The size of the CDISP2D window when opened is always 15cm x 15cm. SCALE and SIGN are active in this window as they are in the density window. The number of contour levels is defined by the LEVEL context; LEVEL contours are displayed in the positive and in the negative part and are equally spaced between 0 and ABSMAX/SCALE in the default mode of LOGA equal to 1. If the context LOGA is set a value larger than 1 then each level is at a position equal to the previous level time LOGA. For instance if with LOGA 1 levels are at :
1 2 3 4 5 6 etc...
with LOGA 1.5 levels will be :
1 1.5 2.25 3.375 5.0625 7.59 etc...
LOGA equal 2 corresponds to the BRUKER standard spacing.
When working full spectrum on large data-set a CDISP2D can take too long, and you may wish to stop the display, you can always do it by typing a ^C.
Contour plot display are normally in colours, with a colour code equivalent to the DISP2D mode, however it is possible to switch to a Black and White mode with the CCOLOR context.
Display are of two kinds : vector mode, used by 1D, 2D contour mode, 3D and the SHOWxxx commands; or image used by density mode in 2D. In vector mode the colour used is determined by the COLOR context which default value is white. The current colour can be chosen separately for each window with the COLOR command. Only 8 colours are available with the COLOR command, they correspond to pure colours when the standard colour file is used. The context SCOLOR determines the colour used by the SHOW and SHOWxxx commands (see below).
The colour table used by the density mode is built when starting the program. The presence of a file called .gifacolor is checked first in the working directory, then in the $HOME directory, then the presence of a file called gifacolor is checked in /usr/local/gifa/com. If one of these file is found, it is used as a list of colours to be used by the density display. The file has one entry per line, first the choice of colours for the pointer, then for the density mode, starting with the large negative value ending with large positive values. Each entry is of the form HUE - SATURATION - INTENSITY. If no file is found, a default set up is used. You will find on the distribution tape a set of small programs that permits to build such custom colour tables. The standard colour table, as well as a Black & White colour table are given as example.
The ZM commands opens a control box which permits to zoom in and out the data-set, to move around the zoom window and to rapidly set the SCALE value. To set the zoom window click on the data-set with the left and middle button of the mouse, and then click on the Zoom In button (or on the display, with the left and right button of the mouse). Other controls in th ZM box are very natural.
ZOOM is a command which permits to define a zoom window on the data-set in a non graphical way. It is perfectly possible to define a zoom window, even if there is no graphic open. Many commands (LINEFIT, PEAK, etc..) only appliy within the current zoom window
MONOPOINT will permit just one click on the data-set. Gifa will be blocked until the user actually clicks on the graphic screen. The coordinate of the click is strored on the top of a special stack (the point stack). This stack is handled with the 4 commands : POINT_INPUT POINT_PUSH, POINT_POP, POINT_CLEAR. The content of this stack is used as default values by many commands (ZOOM, EVALN, BCORR, POINT->PK, etc...) In macro programming the content of the point stack is examined through the variables $POINTX[] $POINTY[] and $NPOINT. The macro point_dump prints out the state of this stack.
The macro point permits to interact with the data, it is based on MONOPOINT. With point, the point stack is cleared, and all the clicked points are stored into the stack. Point is exited by clicking on the data-set with the right-most button of the mouse.
permits to put some information in the graphic window. SHOW takes an argument : CURRENT will show the current data-set as-is; FT will show the FT of it. Other parameters are available, see below or the alphabetic list.
freezes the current graphic window making it inactive, and create a new one equivalent to the previous. This is useful for comparing data.
REF will force a new computing of the display, as if a display command had been issued. This is useful for cleaning the spectrum after a point or whatever command. UNREF realizes just the inverse, i.e. display will not be refreshed, even if the previous commands did modify the data-set. UNREF is usefull in macro for fine control on the display. It is active only for the commands that preceedes it in the command line / macro ; so it is usually the last command issued.
REFMACRO controls whether display will be done at the end of each command line within macro. Default value of 0 means no refreshing during macro execution, which permits much faster execution. If you write interactive macros with graphical display, you should set REFMACRO to 1. It is often useful to change REFMACRO several time within a macro.