Provided by: plplot-doc_5.15.0+dfsg-29_all 
NAME
pllegend - Plot legend using discretely annotated filled boxes, lines, and/or lines of
symbols
SYNOPSIS
pllegend(p_legend_width, p_legend_height, opt, position, x, y, plot_width, bg_color,
bb_color, bb_style, nrow, ncolumn, nlegend, opt_array, text_offset, text_scale,
text_spacing, test_justification, text_colors, text, box_colors, box_patterns, box_scales,
box_line_widths, line_colors, line_styles, line_widths, symbol_colors, symbol_scales,
symbol_numbers, symbols)
DESCRIPTION
Routine for creating a discrete plot legend with a plotted filled box, line, and/or line
of symbols for each annotated legend entry. (See plcolorbar(3plplot) for similar
functionality for creating continuous color bars.) The arguments of pllegend provide
control over the location and size of the legend as well as the location and
characteristics of the elements (most of which are optional) within that legend. The
resulting legend is clipped at the boundaries of the current subpage. (N.B. the adopted
coordinate system used for some of the parameters is defined in the documentation of the
position parameter.)
Redacted form: pllegend(p_legend_width, p_legend_height, opt, position, x, y, plot_width,
bg_color, bb_color, bb_style, nrow, ncolumn, opt_array, text_offset, text_scale,
text_spacing, test_justification, text_colors, text, box_colors, box_patterns, box_scales,
box_line_widths, line_colors, line_styles, line_widths, symbol_colors, symbol_scales,
symbol_numbers, symbols)
This function is used in examples 4, 26, and 33.
ARGUMENTS
p_legend_width (PLFLT_NC_SCALAR(3plplot), output)
Returned value of the legend width in adopted coordinates. This quantity is
calculated from plot_width, text_offset, ncolumn (possibly modified inside the
routine depending on nlegend and nrow), and the length (calculated internally) of
the longest text string.
p_legend_height (PLFLT_NC_SCALAR(3plplot), output)
Returned value of the legend height in adopted coordinates. This quantity is
calculated from text_scale, text_spacing, and nrow (possibly modified inside the
routine depending on nlegend and nrow).
opt (PLINT(3plplot), input)
opt contains bits controlling the overall legend. If the PL_LEGEND_TEXT_LEFT bit is
set, put the text area on the left of the legend and the plotted area on the right.
Otherwise, put the text area on the right of the legend and the plotted area on the
left. If the PL_LEGEND_BACKGROUND bit is set, plot a (semitransparent) background
for the legend. If the PL_LEGEND_BOUNDING_BOX bit is set, plot a bounding box for
the legend. If the PL_LEGEND_ROW_MAJOR bit is set and (both of the possibly
internally transformed) nrow > 1 and ncolumn > 1, then plot the resulting array of
legend entries in row-major order. Otherwise, plot the legend entries in column-
major order.
position (PLINT(3plplot), input)
position contains bits which control the overall position of the legend and the
definition of the adopted coordinates used for positions just like what is done for
the position argument for plcolorbar(3plplot). However, note that the defaults for
the position bits (see below) are different than the plcolorbar(3plplot) case. The
combination of the PL_POSITION_LEFT, PL_POSITION_RIGHT, PL_POSITION_TOP,
PL_POSITION_BOTTOM, PL_POSITION_INSIDE, and PL_POSITION_OUTSIDE bits specifies one
of the 16 possible standard positions (the 4 corners and centers of the 4 sides for
both the inside and outside cases) of the legend relative to the adopted coordinate
system. The corner positions are specified by the appropriate combination of two of
the PL_POSITION_LEFT, PL_POSITION_RIGHT, PL_POSITION_TOP, and PL_POSITION_BOTTOM
bits while the sides are specified by a single value of one of those bits. The
adopted coordinates are normalized viewport coordinates if the PL_POSITION_VIEWPORT
bit is set or normalized subpage coordinates if the PL_POSITION_SUBPAGE bit is set.
Default position bits: If none of PL_POSITION_LEFT, PL_POSITION_RIGHT,
PL_POSITION_TOP, or PL_POSITION_BOTTOM are set, then use the combination of
PL_POSITION_RIGHT and PL_POSITION_TOP. If neither of PL_POSITION_INSIDE or
PL_POSITION_OUTSIDE is set, use PL_POSITION_INSIDE. If neither of
PL_POSITION_VIEWPORT or PL_POSITION_SUBPAGE is set, use PL_POSITION_VIEWPORT.
x (PLFLT(3plplot), input)
X offset of the legend position in adopted coordinates from the specified standard
position of the legend. For positive x, the direction of motion away from the
standard position is inward/outward from the standard corner positions or standard
left or right positions if the PL_POSITION_INSIDE/PL_POSITION_OUTSIDE bit is set in
position. For the standard top or bottom positions, the direction of motion is
toward positive X.
y (PLFLT(3plplot), input)
Y offset of the legend position in adopted coordinates from the specified standard
position of the legend. For positive y, the direction of motion away from the
standard position is inward/outward from the standard corner positions or standard
top or bottom positions if the PL_POSITION_INSIDE/PL_POSITION_OUTSIDE bit is set in
position. For the standard left or right positions, the direction of motion is
toward positive Y.
plot_width (PLFLT(3plplot), input)
Horizontal width in adopted coordinates of the plot area (where the colored boxes,
lines, and/or lines of symbols are drawn) of the legend.
bg_color (PLINT(3plplot), input)
The cmap0 color of the background for the legend (PL_LEGEND_BACKGROUND).
bb_color (PLINT(3plplot), input)
The cmap0 color of the bounding-box line for the legend (PL_LEGEND_BOUNDING_BOX).
bb_style (PLINT(3plplot), input)
The pllsty style number for the bounding-box line for the legend
(PL_LEGEND_BACKGROUND).
nrow (PLINT(3plplot), input)
The number of rows in the matrix used to render the nlegend legend entries. For
internal transformations of nrow, see further remarks under nlegend.
ncolumn (PLINT(3plplot), input)
The number of columns in the matrix used to render the nlegend legend entries. For
internal transformations of ncolumn, see further remarks under nlegend.
nlegend (PLINT(3plplot), input)
Number of legend entries. The above nrow and ncolumn values are transformed
internally to be consistent with nlegend. If either nrow or ncolumn is non-positive
it is replaced by 1. If the resulting product of nrow and ncolumn is less than
nlegend, the smaller of the two (or nrow, if nrow == ncolumn) is increased so the
product is >= nlegend. Thus, for example, the common nrow = 0, ncolumn = 0 case is
transformed internally to nrow = nlegend, ncolumn = 1; i.e., the usual case of a
legend rendered as a single column.
opt_array (PLINT_VECTOR(3plplot), input)
A vector of nlegend values of options to control each individual plotted area
corresponding to a legend entry. If the PL_LEGEND_NONE bit is set, then nothing is
plotted in the plotted area. If the PL_LEGEND_COLOR_BOX, PL_LEGEND_LINE, and/or
PL_LEGEND_SYMBOL bits are set, the area corresponding to a legend entry is plotted
with a colored box; a line; and/or a line of symbols.
text_offset (PLFLT(3plplot), input)
Offset of the text area from the plot area in units of character width.
text_scale (PLFLT(3plplot), input)
Character height scale for text annotations.
text_spacing (PLFLT(3plplot), input)
Vertical spacing in units of the character height from one legend entry to the
next.
text_justification (PLFLT(3plplot), input)
Justification parameter used for text justification. The most common values of
text_justification are 0., 0.5, or 1. corresponding to a text that is left
justified, centred, or right justified within the text area, but other values are
allowed as well.
text_colors (PLINT_VECTOR(3plplot), input)
A vector containing nlegend cmap0 text colors.
text (PLCHAR_MATRIX(3plplot), input)
A vector of nlegend UTF-8 character strings containing the legend annotations.
box_colors (PLINT_VECTOR(3plplot), input)
A vector containing nlegend cmap0 colors for the discrete colored boxes
(PL_LEGEND_COLOR_BOX).
box_patterns (PLINT_VECTOR(3plplot), input)
A vector containing nlegend patterns (plpsty indices) for the discrete colored
boxes (PL_LEGEND_COLOR_BOX).
box_scales (PLFLT_VECTOR(3plplot), input)
A vector containing nlegend scales (units of fraction of character height) for the
height of the discrete colored boxes (PL_LEGEND_COLOR_BOX).
box_line_widths (PLFLT_VECTOR(3plplot), input)
A vector containing nlegend line widths for the patterns specified by box_patterns
(PL_LEGEND_COLOR_BOX).
line_colors (PLINT_VECTOR(3plplot), input)
A vector containing nlegend cmap0 line colors (PL_LEGEND_LINE).
line_styles (PLINT_VECTOR(3plplot), input)
A vector containing nlegend line styles (plsty indices) (PL_LEGEND_LINE).
line_widths (PLFLT_VECTOR(3plplot), input)
A vector containing nlegend line widths (PL_LEGEND_LINE).
symbol_colors (PLINT_VECTOR(3plplot), input)
A vector containing nlegend cmap0 symbol colors (PL_LEGEND_SYMBOL).
symbol_scales (PLFLT_VECTOR(3plplot), input)
A vector containing nlegend scale values for the symbol height (PL_LEGEND_SYMBOL).
symbol_numbers (PLINT_VECTOR(3plplot), input)
A vector containing nlegend numbers of symbols to be drawn across the width of the
plotted area (PL_LEGEND_SYMBOL).
symbols (PLCHAR_MATRIX(3plplot), input)
A vector of nlegend UTF-8 character strings containing the legend symbols.
(PL_LEGEND_SYMBOL).
AUTHORS
Many developers (who are credited at http://plplot.org/credits.php) have contributed to
PLplot over its long history.
SEE ALSO
PLplot documentation at http://plplot.org/documentation.php.
June, 2022 PLLEGEND(3plplot)