====== Statistics control Quantile method ======
==== Description of Method ====
The distribution of all observations within one month timespan is represented by the [[http://en.wikipedia.org/wiki/Quartile|quartiles]] Q1, Q2 and Q3.
The station and month specific reference quartiles Q1', Q2' and Q3' is calculated from the climate database either by the previous ten years or from a regional reference station.
A neighbour station n is selected with a corresponding set of quartiles Q1n, Q2n and Q3n.
The neighbour station also have the station and month specific reference quartiles Q1'n, Q2'n and Q3'n.
An error is detected when
|Q1 - Q1'| - |Q1n - Q1n'| > tol1 and |Q1 - Q1'| > tol2
or
|Q2 - Q2'| - |Q2n - Q2n'| > tol3 and |Q2 - Q2'| > tol4
or
|Q3 - Q3'| - |Q3n - Q3n'| > tol5 and |Q3 - Q3'| > tol6
where
tol1 - tol6 are six tolerance values.
==== Quality Control Level ====
* QC2d-4
==== Run Parameters ====
It shall be possible to run the algorithm for
* UU
* NN
* HL
* VV
* QO
==== Characteristics of the data to which the method is applied ====
__CONTROLINFO AND/OR USEINFO__
* none
__TYPEID, OTHER METADATA__
* all typeid
==== Flag Settings ====
__SPECIFICATION OF CONTROLFLAGS TO BE SET FOR EXPECTED RESULTS OF THE ALGORITHM, I.E. CONSIDER BOTH POSITIVE AND NEGATIVE RESULTS__
* fstat=1 on no error detection
* fstat=2 on error detection
__EXPECTIONS OF THE USEINFO FLAGS CORRESPONDING TO CONTROLINFO FLAG SETTINGS__
* fstat=2 -> useinfo(2)=2
==== Dependencies ====
* Definition of neighbour station
* Definition of regions and related region reference station
* Extracts from KDVH