cdms2.axis:FileAxis

FileAxis.mapInterval(interval, indicator='ccn', cycle=None)

Map coordinate interval to index interval. interval has one of the forms

  • (x,y)

  • (x,y,indicator): indicator overrides keywork argument

  • (x,y,indicator,cycle): indicator, cycle override keyword arguments

  • None: indicates the full interval

where x and y are the endpoints in coordinate space. indicator is a two-character string, where the first character is c if the interval is closed on the left, o if open, and the second character has the same meaning for the right-hand point. Set cycle to a nonzero value to force wraparound.

Returns
The corresponding index interval (i,j), where i<j, indicating
the half-open index interval [i,j), or None if the intersection is empty.
For an axis which is circular (self.topology == ‘circular’), [i,j)
is interpreted as follows (where N = len(self)):

  1. if j<=N, the interval does not wrap around the axis endpoint ..

  2. if j>N, the interval wraps around, and is equivalent to the two consecutive intervals [i,N), [0,j-N)

Example:

if the vector is [0,2,4,…,358] of length 180,and the coordinate interval is [-5,5), the return index interval is[178,183). This is equivalent to the two intervals [178,180) and [0,3).

Note:

if the interval is interior to the axis, but does not span any axis element, a singleton (i,i+1) indicating an adjacent index is returned.