def groupby(self, arr, fields):
"""
Applies a groupby to a struct array based on selected fields.
arr : rarray
A remote array on the server.
fields : list of field names
These are the fields which are used for grouping.
Returns a tuple of the groupby result and the groups.
"""
j = groupby(self.session_url, arr.url, fields)
return (rarray(j["output_gb"], j["dshape_gb"]), rarray(j["output_groups"], j["dshape_groups"]))
def add_computed_fields(self, arr, fields, rm_fields=[], fnname=None):
"""
Adds one or more new fields to a struct array.
Each field_expr in 'fields' is a string/ast fragment
which is called using eval, with the input fields
in the locals and numpy/scipy in the globals.
arr : rarray
A remote array on the server.
fields : list of (field_name, field_type, field_expr)
These are the fields which are added to 'n'.
rm_fields : list of string, optional
For fields that are in the input, but have no expression,
this removes them from the output struct instead of
keeping the value.
fnname : string, optional
The function name, which affects how the resulting
deferred expression dtype is printed.
"""
j = add_computed_fields(self.session_url, arr.url, fields, rm_fields, fnname)
return rarray(j["output"], j["dshape"])
def make_computed_fields(self, arr, replace_undim, fields, fnname=None):
"""
Creates an array with the requested computed fields.
If replace_undim is positive, that many uniform dimensions
are provided into the field expressions, so the
result has fewer dimensions.
arr : rarray
A remote array on the server.
replace_undim : integer
The number of uniform dimensions to leave in the
input going to the fields. For example if the
input has shape (3,4,2) and replace_undim is 1,
the result will have shape (3,4), and each operand
provided to the field expression will have shape (2).
fields : list of (field_name, field_type, field_expr)
These are the fields which are added to 'n'.
fnname : string, optional
The function name, which affects how the resulting
deferred expression dtype is printed.
"""
j = make_computed_fields(self.session_url, arr.url, replace_undim, fields, fnname)
return rarray(j["output"], j["dshape"])
def sort(self, arr, field):
j = sort(self.session_url, arr.url, field)
return rarray(j["output"], j["dshape"])
