Sampling Function
The 1-D sampling function is given by
where
is the Dirac Delta Function. The 2-D version is
which can be weighted to
where
is a reliability weight, 
is a density weight (Weighting Function), and 
is a taper.See also Shah Function, Sinc Function- Darling's Products
- Dart
- Darwin-de Sitter Spheroid
- Darwin's Expansions
- Database
- Data Structure
- Daubechies Wavelet Filter
- Davenport-Schinzel Sequence
- Dawson's Integral
- Day of Week
- de Bruijn Constant
- de Bruijn Diagram
- de Bruijn Graph
- de Bruijn-Newman Constant
- de Bruijn Sequence
- de Bruijn's Theorem
- Debye Functions
- Debye's Asymptotic Representation
- Decagon
- Decagonal Number
- Decagram
- Decic Surface
- Decidable
- Decillion
- Decimal