Table 38 – Entries common to all function dictionaries

Key

Type

Value

FunctionType

integer

(Required) The function type:

0 Sampled function

2 Exponential interpolation function

3 Stitching function

4 PostScript calculator function

Domain

array

(Required) An array of 2 m numbers, where m shall be the number of input values. For each i from 0 to m 1, Domain 2i shall be less than or equal to Domain 2i1 , and the ith input value, x i , shall lie in the interval Domain 2i x i Domain 2i1 . Input values outside the declared domain shall be clipped to the nearest boundary value.

Range

array

(Required for type 0 and type 4 functions, optional otherwise; see below) An array of 2 n numbers, where n shall be the number of output values. For each j from 0 to n 1, Range 2j shall be less than or equal to Range 2j+1 , and the jth output value, y j , shall lie in the interval Range 2j y j Range 2j+1 . Output values outside the declared range shall be clipped to the nearest boundary value. If this entry is absent, no clipping shall be done.