groupby
Dv = groupby(D::GMTdataset, col)::Vector{GMTdataset}Split a GMTdataset by the unique values of the column selected by col.
col can be a column name, either as a String or a Symbol, or a column number. In any case, it must point to a column with integers (normaly a flint (Floating Point Integer)), or a string column. i.e., the last column in a GMTdataset.
Methods
# 1 method for generic function "groupby" from GMT:
[1] groupby(D::GMTdataset{T, 2}, cols::Union{Int64, String, Symbol}) where T<:Real