axis

[Class]
  `axis`

Implements axis displays for the horizontal and vertical dimensions of a Plotter window. Use `log-axis` for logarithmic displays.

`axis` supports the following slot initializations:

`:minimum` number
  The minimum value displayed on the axis. Defaults to 0.
`:maximum` number
  The maximum value displayed on the axis. An axis must have a maximum set but this value can be changed during the display.
`:increment` number
  The stepping amount between axis value labels displayed along the axis. log-axis treats this value as the logarithm base and allows the keyword `:base` to be used in place of `:increment`.
`:ticks-per-increment` number
  The number of ticks, or graduals, drawn within each increment along the axis. If the value is 1 then a single large tick is drawn at each label point. If the value is more than 1 the additional ticks are drawn slightly smaller and evenly spaced within the increment.
`:slot` {symbol | list}
  The slot or slots in CLOS data that the axis accesses in order to plot values. If one slot is specified it determines the position along the axis that the value will appear. If a list of two slots is specified then the second slot controls the point's extent (width or height) along the axis.
`:labeler` {string | function}
  Either a format string or a Lisp function of one argument that will be called to produce each label string drawn along the axis. Defaults to "~2,F", which displays a floating point value rounded to two places.
`:zoom` number
  A zooming scaler for the axis display, defaults to 1. Since this value scales the size of plotter's off-screen bitmap be reasonable.
`:pixels-per-increment` number
  The number of pixels each increment claims along the axis at `:zoom` 1. Defaults to 60 since this number is evenly divisible by so many common values of `:ticks-per-increment`.
`:pixels-per-label` number
  The width/height in pixels of the labeling area on either side of the vertical/horizontal axis lines. Defaults to 60.

#### Examples:

See the Examples section in the Plotter topic documentation.

#### See also:

- `log-axis` [Class]
- `axis` [Function]
- `defaxis` [Macro]
- `plotter` [Function]
- Plotter [Topic]