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Surrounding a dataset by zeros
(zero padding)
is adjoint to throwing away the extended data
(truncation).
Let us see why this is so.
Set a signal in a vector , and
then to make a longer vector ,add some zeros at the end of .This zero padding can be regarded as the matrix multiplication
| |
(11) |

The matrix is simply an identity matrix above a zero matrix .To find the transpose to zero-padding, we now transpose the matrix
and do another matrix multiply:
| |
(12) |

So the transpose operation to zero padding data
is simply *truncating* the data back to its original length.
Module `zpad1` below
pads zeros on both ends of its input.
Modules for two- and three-dimensional padding are in the
library named `zpad2()` and `zpad3()`.
zpad1zero pad 1-D

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Stanford Exploration Project

4/27/2004