Don't know whether Firebird has internal functions for this or not and it
is likely that there are more elegant solutions available, but the below
queries should be ways to get what you ask (although I don't know whether
you want to return all values for mode and whether or not you want the
average in case of two median values).
execute block returns (mode integer) as
declare variable occurences integer;
declare variable dummy integer;
begin
select <MyField>, count(*)
from <MyTable>
group by 1
order by 2 desc
rows 1
into :dummy, :occurences;
for select <MyField>
from <MyTable>
group by 1
having count(*) = :occurences
into :mode do
suspend;
end
execute block returns (median decimal(9, 1)) as
declare variable occurences integer;
declare variable RowsFrom integer;
declare variable RowsTo integer;
begin
select count(*)
from <MyTable>
into :occurences;
RowsFrom = ((:occurences-1)/2)+1;
RowsTo = (:Occurences/2)+1;
with tmp(tmp) as
(select cast(<MyField> as decimal(9, 1))
from <MyTable>
rows :RowsFrom to :RowsTo)
select sum(tmp)/(:RowsTo-:RowsFrom+1)
from tmp
into :Median;
suspend;
end
select max(<MyField>)-min(<MyField>) as Range
from <MyTable>
HTH,
Set
2016-12-01 4:41 GMT+01:00 Roberto Carlos rc.1...@bol.com.br
[firebird-support] <firebird-support@yahoogroups.com>:
> Basics of Statistics - Mathematics: Mean (Average), Median, Mode and Range
>
> I want to calculate Mean (Average), Median, Mode and Range in Firebird 2.5
> and 3.0.
>
> I know that Firebird internal function for Mean (Average) is AVG(), but
> what are the internal functions for Median, Mode and Range in Firebird 2.5
> and 3.0?
>
> If there are not such functions, how can I calculate them using Firebird?
>
> Thanks for all and any help.
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
> Posted by: Roberto Carlos <rc.1...@bol.com.br>
> ------------------------------------
>
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> Visit http://www.firebirdsql.org and click the Documentation item
> on the main (top) menu. Try FAQ and other links from the left-side menu
> there.
>
> Also search the knowledgebases at http://www.ibphoenix.com/
> resources/documents/
>
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>
