| makeTopography {PBSmapping} | R Documentation |
Makes topography data suitable for the contour and
contourLines functions using freely available global
seafloor topography data.
makeTopography (data)
data |
data frame with three optionally-named columns: X,
Y, and Z. The columns must appear in that order. Each
(X, Y) combination must appear exactly once. |
Data obtained through the acquisition form at
http://topex.ucsd.edu/cgi-bin/get_data.cgi is suitable for this
function. read.table will import its ASCII files into
R/S, creating the data argument for this function.
When creating data for regions with longitude values spanning
-180degrees to 0degrees, consider
subtracting 360 from the result's X coordinates (x).
When creating bathymetry data, consider negating the result's
elevations (z) to give depths positive values.
List with elements x, y, and z. x and
y are vectors, while z is a matrix.
contour and contourLines expect data
conforming to this list format.
contour,
contourLines,
convCP,
read.table.
#--- create a sample data frame file <- data.frame(X=c(1, 1, 2, 2), Y=c(3, 4, 3, 4), Z=c(5, 6, 7, 8)) #--- convert that data frame to the output format, and print the results print(makeTopography(file));