Popular recipes tagged "spread"

Equally-spaced numbers (linspace) (Python)

2015-01-12T22:16:37-08:00

Python recipe 579000 by Andrew Barnert (float, linspace, range, spread).

An equivalent of numpy.linspace, but as a pure-Python lazy sequence.

Like NumPy's linspace, but unlike the spread and frange recipes listed here, the num argument specifies the number of values, not the number of intervals, and the range is closed, not half-open.

Although this is primarily designed for floats, it will work for Fraction, Decimal, NumPy arrays (although this would be silly) and even datetime values.

This recipe can also serve as an example for creating lazy sequences.

See the discussion below for caveats.

Generate equally-spaced floats (Python)

2011-09-24T18:49:39-07:00

Python recipe 577878 by Steven D'Aprano (float, range, spread).

Generating a list of equally-spaced floats can surprising due to floating point rounding. See, for example, the recipe for a floating point range. One way of avoiding some surprises is by changing the API: instead of specifying a start, stop and step values, instead use a start, stop and count:

>>> list(spread(0.0, 2.1, 7))
[0.0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8]

Like frange spread takes an optional mode argument to select whether the start and end values are included. By default, start is included and end is not, and exactly count values are returned.

Equally-spaced floats part 2 (Python)

2011-09-27T15:48:00-07:00

Python recipe 577881 by Steven D'Aprano (float, range, spread).

See the recipe here for a description of the problem.

This variant allows the user to choose between two APIs, either by supplying the count, start value and end value:

>>> list(spread(5, 1.0, end=2.0))
[1.0, 1.2, 1.4, 1.6, 1.8]

or the count, start value and step size:

>>> list(spread(5, 1.0, step=-0.25))
[1.0, 0.75, 0.5, 0.25, 0.0]

As before, the count argument specifies how many subdivisions are made. The optional argument mode selects whether the start and end values are included. By default, start is included and end is not, and exactly count values are returned.