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Area
Class area.T
defines the location and size of a chart. It also
defines the coordinate system (linear, log, or enumeration) of the X and
Y axes.
The X (or Y) coordinate system is defined by attribute
x_coord_system
(or y_coord_system
), which takes an object
of type coord.T
. Class coord.T
defines how a X (or a Y)
value will be mapped to a display (canvas) location. PyChart provides
three standard coordinate systems: linear_coord.T
(for linear
mapping; this is the default), log_coord.T
(for logarithmic
mapping), and category_coord.T
(enumeration of values). Most
charts will do ok by instantiating one of these pre-defined coordinate
classes, but you can also define your own wacky coordinate system.
See coord.
For log and linear coordinate systems, the minimum and maximum
displayable values in the area are computed automatically from the plots
unless they are defined explicitly via attribute x_range
. See the
below example:
ar = area.T(x_coord_system = log_coord.T(), x_range = (10, None), ...)
Here, an X axis is drawn with a logarithmic scale. The minimum value
will be 10, and the maximum value will be computed from the values given
to plots. The below is an example of a category coordinate system.
samples = [("apple", 10), ("orange", 30), ("blueberry", 20)],
ar = area.T(x_coord_system = category_coord(samples, 0))
ar.add_plot(bar_plot.T(data = samples))
- coord: Specifying the coordinate system. Linear, log, etc.
- axis: Displaying X and Y axes.
We now list the attributes understood by an area.T
object.
bg_style type: fill_style.T
|
Attribute |
Default: None. Background fill-pattern.
See fill_style.
|
border_line_style type: line_style.T
|
Attribute |
Default: None. Line style of the outer frame of the chart.
See line_style.
|
legend type: legend.T
|
Attribute |
Default: a legend is by default displayed
in the right-center of the chart.. The legend of the chart.
See legend.
|
loc type: (x,y)
|
Attribute |
Default: (0, 0). The location of the bottom-left corner of the chart.
|
size type: (x,y)
|
Attribute |
Default: (120, 110). The size of the chart-drawing area, excluding axis labels,
legends, tick marks, etc.
|
x_axis type: axis.X
|
Attribute |
Default: None. The X axis. See axis..
|
x_axis2 type: axis.X
|
Attribute |
Default: None. The second X axis. This axis should be non-None either when you want to display plots with two distinct domains or when
you just want to display two axes at the top and bottom of the chart.
See axis..
|
x_coord type: coord.T
|
Attribute |
Default: A linear coordinate system.. Set the X coordinate system. See coord..
See coord.
|
x_grid_interval type: Number or function
|
Attribute |
Default: None. The horizontal grid-line interval.
A numeric value
specifies the interval at which
lines are drawn. If value is a function, it
takes two arguments, (MIN, MAX), that tells
the minimum and maximum values found in the
sample data. The function should return a list
of values at which lines are drawn.
|
x_grid_over_plot type: int
|
Attribute |
Default: 0. If true, grid lines are drawn over plots. Otherwise, plots are drawn over grid lines.
|
x_grid_style type: line_style.T
|
Attribute |
Default: None. The style of horizontal grid lines.
See line_style.
|
x_range type: (x,y)
|
Attribute |
Default: None. Specifies the range of X values that are displayed in the
chart. IF the value is None, both the values are computed
automatically from the samples. Otherwise, the value must be a
tuple of format (MIN, MAX). MIN and MAX must be either None or a
number. If None, the value is computed automatically from the
samples. For example, if x_range = (None,5), then the minimum X
value is computed automatically, but the maximum X value is fixed
at 5.
|
y_axis type: axis.Y
|
Attribute |
Default: None. The Y axis. See axis..
|
y_axis2 type: axis.Y
|
Attribute |
Default: None. The second Y axis. This axis should be non-None either when you want to display plots with two distinct ranges or when
you just want to display two axes at the left and right of the chart. See axis..
|
y_coord type: coord.T
|
Attribute |
Default: A linear coordinate system.. Set the Y coordinate system. See coord..
See coord.
|
y_grid_interval type: Number or function
|
Attribute |
Default: None. The vertical grid-line interval. See also x_grid_interval
|
y_grid_over_plot type: int
|
Attribute |
Default: 0. See x_grid_over_plot.
|
y_grid_style type: line_style.T
|
Attribute |
Default: line_style.gray70_dash3. The style of vertical grid lines.
See line_style.
|
y_range type: (x,y)
|
Attribute |
Default: None. Specifies the range of Y values that are displayed in the
chart. IF the value is None, both the values are computed
automatically from the samples. Otherwise, the value must be a
tuple of format (MIN, MAX). MIN and MAX must be either None or a
number. If None, the value is computed automatically from the
samples. For example, if y_range = (None,5), then the minimum Y
value is computed automatically, but the maximum Y value is fixed
at 5.
|
Objects of area.T
also support several methods:
area.T:add_plot PLOT, ...
|
Method |
area.T:draw CANVAS = None
|
Method |
Draw plots, axes, and the legend. This procedure must be called at the
end of every PyChart application.
CANVAS is an optional parameter that specifies the output.
See Drawing on canvas.
|
Converts X XVAL to a coordinate on the canvas (see canvas).
See Unit.
|
Converts Y YVAL to a coordinate on the canvas (see canvas).
See Unit.
|