DM2003 has powerful graphic engine that can display not only "raw" numeric
data, but also arbitrary functions on the given data calculated dynamically without actual
data changes. Series may be in either data or functional mode. Data series must be
associated with worksheet and display numbers from worksheet (possibly transformed by expressions).
Functional (or parameterized) series don't use numeric data; instead, point coordinates are
defined as a result of evaluation of X and Y expressions, both depend on cx
parameter whose values belong linear grid ranged from
cxmin to cxmax
and divided into given number of equal intervals. See expression
syntax for more details about available functions and operators. Notice that
it is possible to enable a cache associated with every series so that point
coordinate calculations will not affect plotting performance.
Why use expressions?
Example: in many cases the electrical conductivity of
semiconductors obeys so-called "activation law": R~exp(Ea/kT).
You can easily linearize R(T) dependence and determine activation energy Ea
if you plot ln(R) vs. 1/T: set Y expression to "ln(cy)" (or just
select logarithmic Y axis tick layout) and X expression
to "1/cx", then use Ruler tool to determine curve slope. In many cases
such "on-fly" plot transformations is much more convenient than direct
data recalculation, and allows you easily make experiments with your data.
Manual Fitter tool available in the
Fitting menu also can help you to find
Series Properties dialog box should be used to change various parameters of
the selected series, grouped on two tabs - Data and View:
Data - based or Parametric radio buttons determine series type. For data -
based series, you should define data range (first line, last line and associated
worksheet). If worksheet is not selected, or first line is greater than last
line, or equal to -1, series is treated as empty and will not be displayed. For
functional series, define parameter range and number of points. Also you may set
interleave factor to make plotting faster if the number of points is more than
X/Y Axis coordinates - select column, error bar column (only for data - based series) and
expression (required for parametric series).
Show points - check this flag and define point attributes if you want to
display points on the plot curve.
Show lines - check this flag and define line properties if you want to
connect curve points with lines. If you uncheck both flags the series will be
not empty, but invisible. For your convenience, there's preview image at this
Caption - like column caption, the plot series can have associated text
string that should be used as a description.
X/Y Axis - select which pair of plot axes should be used to define
coordinate plane. Notice: in DM2003, any plot actually have four
independent coordinate planes, and each series associated with its own
coordinate system! Keep in mind that when you select (or make current)
another series with different set of associated axes, real coordinates
implicitly change as well.
Visible checkbox - determines whether this series should be displayed.
Marker - as of build #325, marker ("leader") position may be changed, so
it can be used to select points.
Area border - select an object from this list to display filled area
limited by series curve and the border of selected object. Any non-empty
series or axis or plot label (only arrows and lines) may be selected.
In addition, you can change various visual attributes of the series such as
colors, point size and shape, line width etc. Warning! if you set line width
greater than 1, display output may seriously slow down and even result in the
crash of video driver if the number of lines is greater than several thousands.
Although with 1px solid line DM2003 can easily display as much as a million of
lines (and this is the fastest mode since only one PolyLine() GDI call is made!),
using line styles and thick lines require so called "geometric" pens which
are many times slower. On Win9.x, it is just impossible to apply a style on the thick
lines, and the number of points in PolyLine() is also limited to several thousands
(this is a limitation of its 16-bit GDI core).