Browse Prior Art Database

Transformation of Spatial Temporal Continuums

IP.com Disclosure Number: IPCOM000105145D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 4 page(s) / 121K

Publishing Venue

IBM

Related People

Beller, A: AUTHOR [+2]

Abstract

Disclosed is the user of transformations to manipulate spatial temporal data in an object-oriented manner. Spatial temporal continuums are objects that make spatial data appear to the user being continuous through time even though only a finite number of instants of the spatial data exists. A number of different kinds of transformations that take one or more continuums as input and output another continuum are required to make spatial temporal continuums useful.

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Transformation of Spatial Temporal Continuums

      Disclosed is the user of transformations to manipulate spatial
temporal data in an object-oriented manner.  Spatial temporal
continuums are objects that make spatial data appear to the user
being continuous through time even though only a finite number of
instants of the spatial data exists.  A number of different kinds of
transformations that take one or more continuums as input and output
another continuum are required to make spatial temporal continuums
useful.  The "distribution" of operations across a continuum by a
transformation and the restriction of a transformation to a time
interval are described as well as some types of transformations;
aggregate transformations that create iso-continuums, a temporal
referencing operation that facilitates transformations of temporally
unmatched operands, and a LAG qualifier that permits a temporal
translation on one or more of the operands.

      If an operation that is defined on a single instance of a
continuum is applied through a transformation on a continuum it is
"distributed" upon each instant of the continuum.  For example, a
continuum containing maps of measurements of daily precipitation of
the United States in 1988 could be transformed into a binary
continuum of daily significant precipitation maps of the United
States in 1988.  This could be done using a reclassification
operation that would assign element having a value greater than a
specified threshold to be one (significant precipitation), and
assigning each spatial element having a value less than the threshold
to zero.  Assume that a spatial temporal continuum named
US_1988_DAILY_PRECIP has been defined which contains 365 maps of
precipitation across the United States for every day in 1988.  Then a
command similar to the following would perform reclassification on
each of the 365 maps in the continuum and produce a new spatial
temporal continuum containing 365 maps called:

      SIGNIFICANT_US_1988_DAILY_PRECIP:

RECLASSIFY US_DAILY_1988_PRECIP ASSIGN 1 TO >+0.5 ASSIGN 0 TO
<0.5
FOR SIGNIFICANT_US_1988_DAILY_PRECIP.

      The domain of a transformation may be restricted to a temporal
sub-interval of a continuum by FROM/TO qualifier.  For example, to
restrict the above transformation of precipitation deviations to the
month of May 1988, the user could have entered the following command:

CALCULATE FROM 5/1/88 TO 5/31/88 (PRECIP_88 - AVE_PRECIP_88)
FOR PRECIP_DEV_MAY88

      An iso-continuum is created by an aggregation transformation on
a continuum.  The aggregation operation is typically statistical such
as the minimum, maximum, mean, standard deviation, or total of each
spatial element throughout the time interval.  For example, if a
continuum DAILY_US_PRECIP has been defined that consists of maps of
daily precipitation across the United States from 1985 to 1989, the
user could generate the iso-continuum of the mean daily rainfall
across the Uni...