on May 5, 2017
Given:
https://www.filemaker.com/help/15/fmp/en/index.html#page/FMP_Help/aggregate-functions.html
Aggregate functions
Note Aggregate functions perform statistical analysis on numbers (and dates or times for some functions) in:
- several fields in a record.
- related fields whether displayed in a portal or not.
- repeating fields
.
Desired:
change the "field(s)" to "field(s) or variable(s)"
Why?
There are many times that the built-in aggregate functions do the job, but only when the data is in a field. This idea may be prohibitive, but if so, please reply with a why!
List() is considered an 'aggregate' and allows variables:
https://www.filemaker.com/help/15/fmp/en/index.html#page/FMP_Help/list.html
field - any related field, repeating field, or set of non-repeating fields; an expression that returns a field, repeating field, or set of non-repeating fields, or a variable.
So? allow the other aggregates use variables!
Example:
Let (
[ _mylist = List ( 1 ; 2 ; 3 ; 4 )
; _return = Average ( _mylist )
]; _return
) // ERROR: <Field Missing>
Why not?
Yes, there are custom functions. Yes, there are ways to use external (i.e. Javascript). Yes, there are plug-ins.
Just posting an idea.
beverly
I don't think the issue is Aggregates and variables. Aggregate functions do permit variables. The error message for Aggregates often claims a need for a field, but that's misleading. Regular numbers work just fine. As do variables that resolve to numbers. Aggregates do not like to be fed a single parameter that is not a field.
For example this works fine:
Let ( [
$x = 5 ;
$y = 4 ];
Average ( $x ; $y )
) //4.5
Even this works fine...
Let (
$x = 4 ;
average ( $x ; $y )
) //4
But you run into problems with passing a single, non-field parameter such as:
Average ( 5 ) //ERROR
and
Let(
$x = "4¶5" ;
average ( $x )
) //ERROR
That last one is what I think you’re suggestion is trying to address. I'm sympathetic, it would be nice to feed a value delimited list to an Aggregate and get a result.
Evaluate() is really handy here. You can do all sorts of things with the Aggregate functions, a list of values, and Evaluate().
For example:
Let (
[ _mylist = List ( 1 ; 2 ; 3 ; 4 )
; _function = "Average ( " & Substitute ( _mylist ; "¶" ; " ; " ) & " ) "
//Average ( 1 ; 2 ; 3 ; 4 )
;_return = Evaluate ( _function )
]; _return
) //2.5
Also if $$my.list = 1¶2¶3¶4
Let (
[ _function = "Average ( " & Substitute ( $$mylist ; "¶" ; " ; " ) & " ) "
//Average ( 1 ; 2 ; 3 ; 4 )
;_return = Evaluate ( _function )
]; _return
) //2.5