Subsections

• The 3-D SURFACE Sub-Menu

The GUI DISPLAY Command

The DISPLAY menu allows other graphical display possibilities in addition to the standard false colour image display. Figure 12 shows the menu button choices.

Figure 12: The Display Menu

The buttons have the following functions:

EXIT Exit display menu

ARC SLICE Define an arc, by entering the end coordinate and a coordinate on the arc, and calculate the 1-D ``slice'' along this arc. This is displayed as an X/Y graph and is saved in the memory.

CONTOUR PLOT Display the ROI as a contour plot

DISTANCE Allows two coordinates to be entered graphically, and calculated the distance between the coordinates in pixel units, and in millimetres, using the currently defined pixel sizes.

? Explanation on each of the menu options

NUMBERS Allow the user to click on coordinates and output the 11 by 11 square of pixel values around the coordinate. (If a log file is open this will be saved in the log file.)

PIXEL (X/Y) Allow the user to click on pixels and display information on the coordinate and pixel values. If the geometry of a diffraction experiment has been defined, then angles and equivalent D-spacings will be calculated and displayed.

PROJECTION Allow the user to define an arbitrary line, and a region either side of the line, and ``project'' the pixel values in the defined region onto the line. This is displayed as an X/Y graph and is saved in the memory. (This is similar to SLICE but allows averaging over several or many pixels.)

HELP Help text explaining the available commands.

SATURATED Count the number of pixels with an intensity greater or equal to an input value.

SLICE Allow the user to click on two coordinates to define an arbitrary ``slice'' through the data. The nearest pixels to the line define the output data values. This is displayed as an X/Y graph and is saved in the memory.

STATISTICS Allow the user to define a arbitrary polygon region, and calculate a number of statistics within this region. e.g. number of pixels, total intensity, mean and standard deviation values. By first defining a background region, followed by a region around a diffraction peak, a primitive form of peak integration is available.

PRINT Save the current graphics display to a PostScript file.

3-D SURFACE The ROI is displayed a 3-D surface perspective view. The surface may additionally be coloured by the current colour table. The viewing angle and many aspects of the display are controlled by a menu. An example of the display and menu are shown in Figure 13. This menu is described in the next section.

3-D LINES Draw the ROI as a 3-D line plot, with hidden line removal.

Figure 13: Example of the 3-D Surface ``Viewer''

The 3-D SURFACE Sub-Menu

The 3-D SURFACE control sub-menu is shown in Figure 13.

The following commands are available:

EXIT Exit 3-D surface viewing sub-menu.

+ROT. Increase longitude angle of viewer.

+ELEV. Increase elevation angle of viewer.

+ZOOM Increase size of object.

LEFT View further to the left of the object.

UP View further above the object.

STEEPER Increase importance of Z-dimension (vertical).

? Explanation of menu options.

-ROT. Decrease longitude angle of viewer.

-ELEV. Decrease elevation angle of viewer.

-ZOOM Decrease size of object.

RIGHT View further to the right of the object.

DOWN View further below the object.

FLATTER Decrease importance of Z-dimension (vertical).

PRINT Output displayed 3-D surface to PostScript output file.

ANGLE Keyboard entry of arbitrary viewing angles.

DEFAULT Re-set default view angles, and zoom factor.

LOG Logarithmic image intensity scaling. When selected this button is replaced by LINEAR to allow selection of linear intensity scaling.

FAST Fast mode of display: lower resolution, and few colours are displayed. This results in many fewer polygons being calculated so display is much faster. This is useful for finding the best viewing angle. When the required view has been found the display style can be re-set to NORMAL.

STYLE Control of 3-D surface display diagram style. This starts a sub-menu which is described below.

360 360 degree rotation in longitude, in 10 degree steps. (Note: This may take some time on older systems and there is no cancel button !)

The STYLE button starts a sub-menu which controls style aspects of the 3-D surface display. This sub-menu is shown in Figure 14.

Figure 14: 3-D Surface Style Control Menu

The style sub-menu has the following commands:

EXIT Exit style sub-menu.

? Explanation of menu options.

HELP Help text.

LIMITS Set output pixel resolution limit and number of colours.

LINES Draw 3-D lines on surface around the re-binned pixels.

FILL Fill areas of 3-D surface with colour.

AXES Draw enumerated axis around the 3-D surface.

TOP IMAGE Add 3-D projected false colour image above 3-D surface.

LOW IMAGE Add 3-D projected false colour image below 3-D surface.