ClassAxes

1. summary Draw a coordinate axis over a specified region
2. labels Reference,Version1

_(This page applies only to the 1.x branch of SVGFig.)_

class Axes

Axes draws coordinate axes. The grid will be curved in non-linear transformations, and can be a good way to "feel" the shape of the transformation.

Arguments

• Axes(xmin, xmax, ymin, ymax, atx, aty, xticks, xminiticks, xlabels, xlogbase, yticks, yminiticks, ylabels, ylogbase, arrows, text_attr, attribute=value)*

	xmin, xmax		_*required*_		the x range
	ymin, ymax		_*required*_		the y range
	atx, aty		_default_=0, 0		point where the axes try to cross; if outside the range, the axes will cross at the closest corner
	xticks		_default_=-10		request ticks according to the [TickSpecification standard tick specification]
	xminiticks		_default_=True		request miniticks according to the [TickSpecification standard minitick specification]
	xlabels		True		request tick labels according to the [TickSpecification standard tick label specification]
	xlogbase		_default_=None		if a number, the x axis is logarithmic with ticks at the given base (10 being the most common)
	yticks		_default_=-10		request ticks according to the [TickSpecification standard tick specification]
	yminiticks		_default_=True		request miniticks according to the [TickSpecification standard minitick specification]
	ylabels		True		request tick labels according to the [TickSpecification standard tick label specification]
	ylogbase		_default_=None		if a number, the y axis is logarithmic with ticks at the given base (10 being the most common)
	arrows		_default_=None		if a new string identifier, draw arrows referenced by that identifier
	text_attr		_default_={}		SVG attributes for the text labels
	attribute=value pairs		_keyword list_		SVG attributes for all lines

To draw arrows on the ends of the axes, pass a new text identifier to `arrows`. Axes will then create four new SVG marker objects with this structure:

SVG("marker", SVG("path", d="M 9 3.6 L 10.5 0 L 0 3.6 L 10.5 7.2 L 9 3.6 Z"), \
              viewBox="0 0 10.5 7.2", refX="9", refY="3.6", markerWidth="10.5", markerHeight="7.2", \
              markerUnits="strokeWidth", orient="auto", stroke="none", fill="black")

and identifiers ending in ".xstart", ".xend", ".ystart", ".yend". These identifiers must be unique, or the axes will reference the wrong markers.

Defaults

Axes have the following defaults, as described in [GeneralPrimitive General features for all primitives].

	defaults		{"stroke-width":"0.25pt"}
	text_defaults		{"stroke":"none", "fill":"black", "font-size":5}

class XAxis

Only draws the x axis.

Arguments

• XAxis(xmin, xmax, aty, ticks, miniticks, labels, logbase, arrow_start, arrow_end, exclude, text_attr, attribute=value)*

	xmin, xmax		_*required*_		the x range
	aty		_default_=0		y position to draw the axis
	ticks		_default_=-10		request ticks according to the [TickSpecification standard tick specification]
	miniticks		_default_=True		request miniticks according to the [TickSpecification standard minitick specification]
	labels		True		request tick labels according to the [TickSpecification standard tick label specification]
	logbase		_default_=None		if a number, the x axis is logarithmic with ticks at the given base (10 being the most common)
	arrow_start		_default_=None		if a new string identifier, draw an arrow at the low-end of the axis, referenced by that identifier; if an SVG marker object, use that marker
	arrow_end		_default_=None		if a new string identifier, draw an arrow at the high-end of the axis, referenced by that identifier; if an SVG marker object, use that marker
	exclude		_default_=None		if a (low, high) pair, don't draw text labels within this range
	text_attr		_default_={}		SVG attributes for the text labels
	attribute=value pairs		_keyword list_		SVG attributes for all lines

The `exclude` option is provided for Axes to keep text from overlapping where the axes cross. Normal users are not likely to need it.

Defaults

XAxis has the following defaults, as described in [GeneralPrimitive General features for all primitives].

	defaults		{"stroke-width":"0.25pt"}		default SVG attributes for all lines
	text_defaults		{"stroke":"none", "fill":"black", "font-size":5, "dominant-baseline":"text-before-edge"}		default SVG attributes for text labels
	text_start		-1		position relative to the axis (in SVG units) to set text labels
	text_angle		0		angle (in degrees) to rotate text
	tick_start		-1.5		position relative to the axis (in SVG units) to start the ticks
	tick_end		1.5		position relative to the axis (in SVG units) to end the ticks
	minitick_start		-1.5		position relative to the axis (in SVG units) to start the miniticks
	minitick_end		1.5		position relative to the axis (in SVG units) to end the miniticks

XAxis also has the same defaults as [ClassCurve Curve].

	random_sampling		True		if False, bisect with a point exactly halfway between pairs of points; if True, randomly choose a point between 30% and 70%
	recursion_limit		15		number of subdivisions before giving up; if 15, sampling algorithm can visit _at most_ 2^15^ points
	linearity_limit		0.05		maximum deviation (in SVG units) from a straight line
	discontinuity_limit		5		minimum deviation (in SVG units) between points that is considered continuous

class YAxis

Only draws the y axis; arguments are similar to XAxis.

Defaults

YAxis has the following defaults, as described in [GeneralPrimitive General features for all primitives].

	defaults		{"stroke-width":"0.25pt"}		default SVG attributes for all lines
	text_defaults		{"stroke":"none", "fill":"black", "font-size":5, "text-anchor":"end", "dominant-baseline":"middle"}		default SVG attributes for text labels
	text_start		2.5		position relative to the axis (in SVG units) to set text labels
	text_angle		90		angle (in degrees) to rotate text
	tick_start		-1.5		position relative to the axis (in SVG units) to start the ticks
	tick_end		1.5		position relative to the axis (in SVG units) to end the ticks
	minitick_start		-1.5		position relative to the axis (in SVG units) to start the miniticks
	minitick_end		1.5		position relative to the axis (in SVG units) to end the miniticks

YAxis also has the same defaults as [ClassCurve Curve].

Special data members

When an XAxis or a YAxis is evaluated with *SVG*, it will gain two members.

• *last_ticks*: explicit dict of value, label pairs for major ticks
• *last_miniticks*: explicit list of values for miniticks

SVG method

Axes, XAxis, and YAxis have *SVG* methods, as described in [GeneralPrimitive General features for all primitives].