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Overview
Comment:Enhancements to the geopoly documentation.
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 3ab6e3f6a6897ac28b616e54a8342400d564cda071d601343b86d904da15e7e8
User & Date: drh 2018-12-01 19:17:36
Context
2018-12-01
20:55
Adjust the date for 3.26.0 in the speed and size chart. check-in: 41f2b76661 user: drh tags: trunk
19:17
Enhancements to the geopoly documentation. check-in: 3ab6e3f6a6 user: drh tags: trunk
12:41
Version 3.26.0 check-in: 7463317ee9 user: drh tags: trunk, release, version-3.26.0
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Changes to pages/geopoly.in.

   146    146   either the GeoJSON format or the internal binary format.
   147    147   
   148    148   <tcl>hd_fragment goverlap geopoly_overlap</tcl>
   149    149   <h2>The geopoly_overlap(P1,P2) Function</h2>
   150    150   
   151    151   <p>
   152    152   If P1 and P2 are both polygons, then the geopoly_overlap(P1,P2) function returns
   153         -true if there is any overlap between P1 and P2, or it returns false if P1 and P2
   154         -completely disjoint.
          153  +a non-zero integer if there is any overlap between P1 and P2, or it returns
          154  +zero if P1 and P2 completely disjoint.
   155    155   If either P1 or P2 is not a polygon, this routine returns NULL.
   156    156   
   157    157   <p>
   158    158   The geopoly_overlap(P1,P2) function is special in that the geopoly virtual
   159    159   table knows how to use R*Tree indexes to optimize queries in which the 
   160    160   WHERE clause uses geopoly_overlap() as a boolean function.  Only the
   161    161   geopoly_overlap(P1,P2) and geopoly_within(P1,P2) functions have this
................................................................................
   162    162   capability.
   163    163   
   164    164   <tcl>hd_fragment gwithin geopoly_within</tcl>
   165    165   <h2>The geopoly_within(P1,P2) Function</h2>
   166    166   
   167    167   <p>
   168    168   If P1 and P2 are both polygons, then the geopoly_within(P1,P2) function returns
   169         -true if P2 is completely contained within P1, or it returns false if any part of
   170         -P2 is outside of P1.  If P1 and P2 are the same polygon, this routine returns true.
          169  +a non-zero integer if P2 is completely contained within P1, or it returns zero
          170  +if any part of P2 is outside of P1.  If P1 and P2 are the same polygon, this routine
          171  +returns non-zero.
   171    172   If either P1 or P2 is not a polygon, this routine returns NULL.
   172    173   
   173    174   <p>
   174    175   The geopoly_within(P1,P2) function is special in that the geopoly virtual
   175    176   table knows how to use R*Tree indexes to optimize queries in which the 
   176    177   WHERE clause uses geopoly_within() as a boolean function.  Only the
   177    178   geopoly_within(P1,P2) and geopoly_overlap(P1,P2) functions have this
................................................................................
   238    239   The geopoly_group_bbox(P) function returns the smallest rectangle that will
   239    240   enclose all P values seen during aggregation.
   240    241   
   241    242   <tcl>hd_fragment gpoint geopoly_constains_point</tcl>
   242    243   <h2>The geopoly_contains_point(P,X,Y) Function</h2>
   243    244   
   244    245   <p>
   245         -If P is a polygon, then geopoly_contains_point(P,X,Y) returns true if and only
          246  +If P is a polygon, then geopoly_contains_point(P,X,Y) returns a 
          247  +non-zero integer if and only
   246    248   if the coordinate X,Y is inside or on the boundary of the polygon P.
   247    249   If P is not a polygon, geopoly_contains_point(P,X,Y) returns NULL.
   248    250   
   249    251   <tcl>hd_fragment xform geopoly_xform</tcl>
   250    252   <h2>The geopoly_xform(P,A,B,C,D,E,F) Function</h2>
   251    253   
   252    254   <p>