Usage
combine.rt(lat, lon, z, grlat, grlon = 0, fun, fill = F, reg = 0, minnumber = 2, wsp = 0, wz = 0, wlat = 0, xy = F, rat = 0.2, type)
Arguments
lat
Latitude of datapoints. ( or x coordinates)
lon
Longitude of datapoints. (or y coordinate)
grlat
Latitude of defined grid.
grlon
Longitude of defined grid. If 0 grlat is a list with
components \$lat and \$lon.
fill
If fill is T the center points of squares where the number of
points does not reach the minimum is set to zero. Good for data like
trawlers report where it can be assumed that there is little fish where they
do not try.
reg
List with two components \$lat and \$lon. Points outside region
are not returned. The list is typically output from the program
define.area.
minnumber
Minimum number of points needed for the square to be valid.
Default value is 2.
wsp
Workspace. Not of interest.
wz
Weighing for the z values. If one is trying to find the mean
tons/hour in an area is it reasonable to weigh tons/hour by the catch. If
the weight is zero within a square unweighed mean is used.
wlat
Weighing to find the mean latitude and mean longitude. It is
often reasonable to weigh the latitude and the longitude by the catch.
xy
Projected? Default unprojected (lat/lon) values, FALSE.
rat
Ratio for "rm.outliers". If rat is for example 0.2 20% of the
points on each side are moved. i.e. the middle 60% are kept. Default
value is 0.6.
type
Only value with description rm.outliers.
Value
List with components \$lat,\$lon,\$z,\$n and
\$fill. \$lat mean latitude of points within each square. \$lon mean
longitude of points within each square \$z sum, mean, variance or median of
data \$n Number of points behind point. If type = "rm.outliers" \$n this component stores the number of the square
corresponding to each point. \$fill If 0 there are datapoints behind the
points else it is an artificial point. (fill = T)