For all the 2D-options, when the mouse cursor lies over the map image, a continuous display of the current cursor position (map x- and y-coordinates) and function density at that point is given. In this mode the cursor changes from the normal arrow-cursor to a cross-hair cursor. Maps containing more than one section may be advanced or retraced using the Frame or Frame buttons and a particular section may be selected with the Select Section button. If the map contains more than one section, it may be quickly visualised with the StartMovie button which moves continuously, section by section up and down the map until any key is hit or the mouse-cursor is moved over the canvas. The StartMovie option is only available for the vector-illustrations (styles 1,2 and 5), since the other styles are too time-consuming to draw. Parameters relating to the currently loaded map and currently selected section is given in a panel to the side of the graphics window. A number of options may be set using the dialog window shown below.
7.3.2.1 Contours
No interpolation is used to generate the contours, so if smoother sections are required, the map must be recalculated using a finer grid. Contours are drawn at equal intervals between the maximum and minimum densities, so that the contour interval is given by : contour interval = (max-r - min-r)/(NCONT+1) The contour interval may be explicitly set using the Options[Set Contours] menu item. If the required number of contour levels is less than 25, then this number of contours is used. If the required number of contour levels is greater than 25, then the number of contour levels used is unchanged from the current value, but the map maximum is reduced to give the required contour interval.
7.3.2.2 Maximum/minumum density
The maximum density is by default the highest point in the MapFile, the minimum density the
lowest point. Different values may be selected for either parameter. This has the effect of
truncating the density at these level(s), a feature which is useful in examining weak features
in the presence of intense peaks.
7.3.2.3 Atoms, bonds and atom labels
Atoms, bonds and atom-labels may be overlaid in the 2D-options only. The bond-distance
calculation is unsophisticated - a bond will be drawn between every pair of atoms whose
distance fulfils the criterion.
Min. bond distance > distance > Max. bond distance
7.3.2.4 Colour-tables
The colours for the colour-tables are taken from PGXTAL and are stored internally. It is
possible to modify these colours in two ways. The colour-intensity may be reduced from the
normal level of 1.0 (which gives the pure colour-map) since these pure colours are quite
garish and difficult to look at. The default colour intensity of 0.75 gives a more reasonable
colour scheme. The contrast may also be changed from the default value. A value smaller
than 1.0 emphasises the lower intensities, while a value larger than 1.0 emphasises the higher
intensities. The user needs to experiment to find the optimum settings.
7.3.2.5 Axial scaling
If the angle between the two projected axes (given as ANGLE in the display) differs from 90o
or the axial lengths are unequal, then axial scaling is automatically chosen if options 1 or 3
are selected (axial scaling cannot be used for option 2). This action may be deselected using
the Options[Use axial scaling] menu item.
7.3.3 Menu Options
7.3.3.1 Open Mapfile...
Reads in a new MapFile, which will be called either MapFile or name.MAP. On startup,
MAPVIEW will load the file MapFile if it finds it in the current working directory. Axial
scaling is set automatically if non-equal or non-orthogonal axes are
read from the MapFile.
7.3.3.2 Save as PostScript
The current image will be saved as a colour or monochrome PostScript file. It is named
automatically as MAPVxxx.PS where xxx = 001-999. Previously written PostScript files will
not be overwritten.
7.3.3.3 Save as BMP
The current image will be saved as a Window BMP file. It is named automatically as
MAPVxxx.BMP where xxx = 001-999. Previously written BMP files will not be overwritten.
The size will depend on the graphical resolution and colour-depth of your monitor.
7.3.3.4 Copy To Clipboard
The current image is copied to the clip-board, form where it may be inserted as a graphical
object into other programs.
7.3.3.5 Print...
The current image is sent to the local printer. The current colour scheme will be used (except
that the background is always printed as white).
7.3.3.6 Select Colours/Load Default Colours
The display colours may be individually selected. The foreground colours is used for the
contours. The colour tables are unaffected by this option. Load Default Colours returns all
individually selected colours to their default values.
7.3.7 Options
This opens the above-shown dialog box which allows the user to set a number of parameters.
7.3.4 Program limitations
7.3.7 Graphics acknowledgement
The graphics in this program use the PGPLOT library (version 5.2.0) of Tim Pearson
(http://astro.caltech.edu/~tjp/pgplot/index.html)
and a heavily modified version of the PGXTAL library of Devinder Sivia
.
(http://www.isis.rl.ac.uk/dataanalysis/dsplot/).