PLplot can draw graphs consisting of points with optional error bars,
line segments or histograms. Functions which perform each of these
actions may be called after setting up the plotting environment using
plenv. All of the following functions draw within the box defined
by plenv, and any lines crossing the boundary are clipped.
Functions are also provided for drawing surface and contour
representations of multi-dimensional functions. See Chapter 3, Advanced Use of PLplot for discussion of finer control of plot
generation.
plstring, plpoin, and plsym plot
n points (x[i], y[i]) using the
specified symbol. The routines differ only in how the plotted symbol
is specified. plstring is now the preferred way of drawing points
for unicode-aware devices because it gives users full access via a
UTF-8 string to any unicode glyph they prefer for the symbol that is
is available via system fonts. plpoin and plsym are limited to
Hershey glyphs and are therefore more suitable for device drivers that
only use Hershey fonts. For both of these functions the Hershey glyph
is indicated by a code value. plpoin uses an extended ASCII index
of Hershey glyphs for that code value, with the printable ASCII codes
mapping to the respective characters in the current Hershey font, and
the codes from 0–31 mapping to various useful Hershey glyphs for
symbols. In plsym however, the code is a Hershey font code number.
Standard examples 04, 21, and 26, demonstrate
use of plstring while standard example
06 demonstrates all the Hershey symbols available with
plpoin and standard example
07 demonstrates all the Hershey symbols available with
plsym.
PLplot provides two functions for drawing line graphs. All lines are drawn in the currently selected color, style and width. See the section called “Setting Line Attributes” for information about changing these parameters.
plline draws a line or curve. The curve consists of
n-1 line segments joining the n
points in the input arrays. For single line segments, pljoin is
used to join two points.
The plptex API allows UTF-* text to be written anywhere within the limits set by plenv
with justification and text angle set by the user.
Area fills are done in the currently selected color, line style, line width and pattern style.
plfill fills a polygon. The polygon consists of
n vertices which define the polygon.
Functions plbin and plhist are provided for drawing histograms,
and functions plerrx and plerry draw error bars about specified
points. There are lots more too (see Chapter 17, The Common API for PLplot).