Changes between Version 14 and Version 15 of Grass7/TemporalGISAlgebra


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Timestamp:
Jul 5, 2013, 8:42:02 AM (11 years ago)
Author:
huhabla
Comment:

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  • Grass7/TemporalGISAlgebra

    v14 v15  
    167167
    168168The temporal raster algebra uses all operators and functions of the temporal
    169 algebra and adds a subset of the arithmetic operators and function of r.mapcalc.
    170 
    171 The method is the same as for the temporal vector algebra.
    172 Hence new spatio-temporal operators are defined that include temporal topology relations,
     169algebra and adds a subset of the arithmetic operators and functions from r.mapcalc.
     170New spatio-temporal operators are defined that include temporal topology relations,
    173171temporal operators and arithmetic operators.
    174172
    175173Examples:
    176 Create the sum all maps from STRDS A and B that have equal time stamps and store the new maps in STRDS C.
     174Create the sum of all maps from STRDS A and B that have equal time stamps and store the new maps in STRDS C:
    177175{{{
    178176C = A + B
    179177}}}
    180 Same expression with explicit definition of the temporal topology relation and temporal operators.
     178Same expression with explicit definition of the temporal topology relation and temporal operators:
    181179{{{
    182180C = A {equal,=+} B
    183181}}}
    184182Select all cells from STRDS B with equal relations to STRDS A if the cells
    185 of A are in the range of [100.0, 1600] of time intervals that have more then 30 days
     183of A are in the range of [100.0, 1600] of time intervals that have more then 30 days:
    186184{{{
    187185C = if(A > 100 && A < 1600 && td(A) > 30, B)
    188 
    189 same as:
    190 
     186}}}
     187Same expression with explicit definition of the temporal topology relation and temporal operators:
     188{{{
    191189C = if(equal, A > 100 && A < 1600 {equal,&&} td(A) > 30, B)
    192190}}}
     
    195193{{{
    196194C = if(Temp > 10.0, Prec / 3600.0 /24.0 / td(Prec))
    197 
    198 same as:
    199 
     195}}}
     196Same expression with explicit definition of the temporal topology relation and temporal operators:
     197{{{
    200198C = if(equal, Temp > 10.0, Prec / 3600.0 / 24.0 {equal,=/} td(Prec))
    201199}}}