DENSITY command
Syntax: |
DENSITY { x y } z
|
Qualifiers: |
\GRADIENTS, \DITHERING, \DIFFUSION, \BOXES, \PARTIAL, \XPROFILE, \YPROFILE,
\BORDER, \AXES, \RESET
|
Defaults: |
\GRADIENTS, \-PARTIAL, \-XPROFILE, \-YPROFILE, \BORDER, \AXES, \RESET
|
This command produces a density plot for either data contained in a matrix or a scattered set of points contained in three vectors.
Density plot types
There are four types of density plot available. The default, requiring no special qualifier, uses color gradients. Other types are chosen by using the appropriate qualifier.
density plot types | qualifier |
color gradients | \GRADIENTS (default) |
dithering with points (grey scales) | \DITHERING |
diffusion with points (grey scales) | \DIFFUSION |
scaled rectangles | \BOXES |
Draw axes
By default, axes are drawn for the density plot. If the density plot is to be
overlayed on an existing set of axes, use the \-AXES
qualifier and no axes
will be drawn. The axis scales will be left at their current values.
Draw rectangular boundary
The \BORDER
qualifier is valid only if matrix data is entered. By default, the
rectangular boundary of the matrix is outlined within the axes. If you do not want this
boundary to be drawn, use the \-BORDER
qualifier.
Zoom in
By default, the entire range of possible density levels will be used to
determine the minimum and maximum density levels. If the
\PARTIAL
qualifier is used, the
minimum and maximum density levels will be determined by the region contained
within the axes. To zoom in on a particular region for more detail, pre-set
the axis scales, using the
SCALES
command, before entering the
DENSITY
command.
Profiles
The qualifiers \XPROFILE
and \YPROFILE
are valid only if matrix
data is entered.
If the \XPROFILE
qualifier is used,
the columns of the matrix are summed, the sums are normalized to be between
0
and 1
, and a histogram of the normalized sums is
drawn horizontally across the top of the graph.
If the \YPROFILE
qualifier is used,
the rows of the matrix are summed, the sums are normalized to be between
0
and 1
, and a histogram of the normalized sums is
drawn vertically along the right side of the graph.
When a profile is drawn, the axis borders must also be set to allow space for
the profiles, that is, XUPPERAXIS
is set to 65%
if a legend is present or 85%
if there is no legend, and YUPPERAXIS
is set to 80%
.
By default, XUPPERAXIS
and YUPPERAXIS
are reset to their former values.
If the \-RESET
qualifier is used, the axis locations are not reset.