This function calculates spatial balance grid cell extent and proportions for the sample frame.
sbcframe(shapefilename = NULL, spframe = NULL, nrows = 5,
dxdy = TRUE)
Name of the input shapefile. If shapefilename equals NULL, then the shapefile or shapefiles in the working directory are used. The default is NULL.
An sp package object of class SpatialPointsDataFrame, SpatialLinesDataFrame, or SpatialPolygonsDataFrame that contains the survey design frame. The default is NULL.
Number of rows (and columns) for the grid of cells. The default is 5.
Indicator for equal x-coordinate and y-coordinate grid cell increments, where TRUE means the increments are equal and FALSE means the increments are not equal. The default is TRUE.
List containing the following components:
the frame extent for each grid cell
the frame proportion for each grid cell
the grid x-coordinate minimum value
the grid x-coordinate maximum value
the grid y-coordinate minimum value
the grid y-coordinate maximum value
the grid cell x-coordinate increment value
the grid cell y-coordinate increment value
the vector of grid cell x-coordinates
the vector of grid cell y-coordinates
readShapeFile
C function to read a single shapefile or multiple shapefiles
readShapeFilePts
C function to read the shp file of a point shapefile and return a data frame containing the x-coordinates and y-coordinates for elements in the frame
cell.wt
calculates number of points in a cell for a points object
insideLinearGridCell
C function to determine ID value and clipped polyline length for shapefile records contained in the selected grid cells
insideAreaGridCell
C function to determine ID value and clipped polygon area for shapefile records contained in the selected grid cells