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missing
Missing

Missing

Mojo struct 🡭

Missing

@memory_only
struct Missing

How a plot treats a missing value, which every column carries as NaN once it is inside a Plot.

A dataframe column’s validity bitmap becomes NaN when it is read (frame_input.mojo), and a caller passing lists writes NaN for the same meaning, so one marker reaches every mark, scale and statistic. The cost of that choice is stated plainly: a computed NaN – 0/0 in a caller’s own arithmetic – is indistinguishable from an absent measurement, and reads as missing.

DRAW, the default, treats the two kinds of column differently, because they are different questions.

A value column holds a number, and a number that was never measured has nowhere to sit on an axis: the observation drops out. A line breaks rather than bridging the hole, a point is not drawn, a matrix cell stays empty, and a statistic is computed from what is there. The one thing no mark does is join the two sides of a gap, which would claim a measurement that was never made.

A category column is not a measurement but a label, and “not recorded” is a label a reader often wants to see: those rows become their own category, named by Theme.missing_category_label ("(missing)" by default), keeping their values in the chart rather than dropping observations that are perfectly good apart from a blank field. Set the policy to RAISE to refuse them instead.

RAISE keeps the old strictness: any NaN in a numeric channel is refused at encode time, naming the column and index. Infinity is refused under both, always: it is not a missing value, it is a number no axis can place.

Aliases

  • DRAW = Missing(Int(0)): Draw what is there and leave the gaps visible. The default.
  • RAISE = Missing(Int(1)): Refuse any missing value, as this package did before #367.

Implemented traits

AnyType, Copyable, Deinitable, ImplicitlyCopyable, Movable

Methods

__init__ 

fn def __init__(out self, value: Int)

Prefer the DRAW/RAISE comptime constants over constructing one directly.

Args:

  • value (Int): 0 for DRAW, 1 for RAISE.
  • self (Self)

Returns:

Self

__eq__ 

fn def __eq__(self, other: Self) -> Bool

Args:

  • self (Self)
  • other (Self)

Returns:

Bool

__ne__ 

fn def __ne__(self, other: Self) -> Bool

Args:

  • self (Self)
  • other (Self)

Returns:

Bool