Function stddev() calculates the standard deviation of numbers in an alias (ignoring the rows that are null). Only one row from the alias will be kept after this function is called, and all the rest rows will be abandoned.
Arguments：
- Alias <number | time>
Returns：
- Stddev value <number | time>
Sample graph: (to be used for the following examples)
create().node_schema("professor").node_schema("student")
create().node_property(@*, "age", int32).node_property(@*, "email", string)
insert().into(@professor).nodes([{_id:"P001",_uuid:1,age:53,email:"[email protected]"},{_id:"P002",_uuid:2,age:27,email:"[email protected]"}])
insert().into(@student).nodes([{_id:"S001",_uuid:3,age:27,email:"[email protected]"},{_id:"S002",_uuid:4,age:20,email:"[email protected]"},{_id:"S003",_uuid:5,age:25,email:"[email protected]"}])
Common Usage
Example: Calculate the standard deviation of age of all nodes in the graph
find().nodes() as n
return stddev(n.age)
11.5861986863682