Description Usage Arguments Details Value Author(s) See Also Examples

Find the polygons in a PolySet that contain events specified in EventData.

1 | ```
findPolys (events, polys, maxRows = 1e+05, includeBdry=NULL)
``` |

`events` |
EventData to use. |

`polys` |
PolySet to use. |

`maxRows` |
estimated maximum number of rows in the output LocationSet. |

`includeBdry` |
numeric: determines how points on boundaries are handled: |

The resulting data frame, a LocationSet, contains the columns
`EID`

, `PID`

, `SID`

(*if in* `polys`

), and
`Bdry`

, where an event (`EID`

) occurs in a polygon
(`PID`

, `SID`

) and `SID`

does not correspond to an
inner boundary. The Boolean variable `Bdry`

indicates whether an
event lies on a polygon's edge. Note that if an event lies properly
outside of all the polygons, then a record with (`EID`

,
`PID`

, `SID`

) does not occur in the output. It may happen,
however, that an event occurs in multiple polygons. Thus, the same
`EID`

can occur more than once in the output.

If an event happens to lie at the boundary intersection of two or more polygons
then one `EID`

will be associated with two or more polygons. A user
can choose to manipulate this result by setting the argument `includeBdry`

to a numeric value that constrains the association of a boundary event to
0 or 1 polygon (see argument description above).

LocationSet that links events with polygons.

Nicholas M. Boers, Associate Professor – Computer Science

MacEwan University, Edmonton AB

Last modified `Rd: 2014-12-15`

`combineEvents`

,
`findCells`

,
`locateEvents`

,
`locatePolys`

,
LocationSet,
`makeGrid`

.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | ```
local(envir=.PBSmapEnv,expr={
oldpar = par(no.readonly=TRUE)
#--- create some EventData: a column of points at X = 0.5
events <- data.frame(EID=1:10, X=.5, Y=seq(0, 2, length=10))
events <- as.EventData(events, projection=1)
#--- create a PolySet: two squares with the second above the first
polys <- data.frame(PID=c(rep(1, 4), rep(2, 4)), POS=c(1:4, 1:4),
X=c(0, 1, 1, 0, 0, 1, 1, 0),
Y=c(0, 0, 1, 1, 1, 1, 2, 2))
polys <- as.PolySet(polys, projection=1)
#--- show a picture
plotPolys(polys, xlim=range(polys$X)+c(-0.1, 0.1),
ylim=range(polys$Y)+c(-0.1, 0.1), projection=1);
addPoints(events, col=2);
#--- run findPolys and print the results
print(findPolys(events, polys))
par(oldpar)
})
``` |

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