ClassYErrorBars

1. summary Draw error bars at a set of points
2. labels Reference,Version1

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

class YErrorBars

YErrorBars draws y error bars at a set of points. This is usually used before (under) a set of [ClassDots Dots] at the same points.

Arguments

• YErrorBars(d, attribute=value)*

	d		_*required*_		list of (x,y,yerr...) points
	attribute=value pairs		_keyword list_		SVG attributes

If points in `d` have

• 3 elements, the third is the symmetric error bar
• 4 elements, the third and fourth are the asymmetric lower and upper error bar. The third element should be negative, e.g. (5, 5, -1, 2) is a bar from 4 to 7.
• more than 4, a tick mark is placed at each value. This lets you nest errors from different sources, correlated and uncorrelated, statistical and systematic, etc.

Note lists like (x,y,yerr) can be constructed with Python's `zip` function.

>>> x = [1,2,3,4,5]
>>> y = [1,4,9,16,25]
>>> yerr = [0.1, 0.2, 0.3, 0.4, 0.5]
>>> zip(x,y)
[(1, 1, 0.1), (2, 4, 0.2), (3, 9, 0.3), (4, 16, 0.4), (5, 25, 0.5)]

class XErrorBars

XErrorBars draws x error bars at a set of points. This is usually used before (under) a set of [ClassDots Dots] and maybe YErrorBars at the same points.

In all respects, XErrorBars acts like YErrorBars.

SVG method

XErrorBars and YErrorBars have *SVG* methods, as described in [GeneralPrimitive General features for all primitives].

Defaults

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

defaults

{"stroke-width":"0.25pt"}

Trivia

Error bars are implemented with short coordinate axes that usually have only two unlabeled tickmarks.