topic Re: Date Difference calculation referencing grouping columns in Discussions

Date Difference calculation referencing grouping columns

ktbrickey — Wed, 20 May 2020 14:26:41 GMT

I am trying to calculate a Date Difference in Days between the current row and the last row where a comment is non-missing. Any help greatly appreciated!

If( (:ID == Lag( :ID ) | Row() == 1) & !Is Missing( :Comments ), 0,
Date Difference( :Sampled Date, Lag(:Sampled Date, n=last row where !Is Missing(:Comments)), "Day" )
)

Re: Date Difference calculation referencing grouping columns

ih — Wed, 20 May 2020 18:48:59 GMT

If the table is always sorted by date you could do this with two columns, as shown below.

New Column( "Last Comment Date",
	Numeric,
	"Continuous",
	Format( "m/d/y h:m", 19 ),
	Input Format( "Monddyyyy h:m" ),
	Formula(
		If(
			Row() == 1, :Sampled Date,
			:Comments == Lag( :Comments, 1 ), Lag( :Sampled Date, 1 ),
			:Sampled Date
		)
	),
	Set Display Width( 136 )
);
New Column( "Days Since Last Comment New",
	Numeric,
	"Continuous",
	Format( "Best", 12 ),
	Formula( (:Sampled Date - :Last Comment Date) / (3600 * 24) ),
	Set Display Width( 109 )
);

Re: Date Difference calculation referencing grouping columns

txnelson — Wed, 20 May 2020 19:17:43 GMT

Here is the formula that I would use for the calculation

If( Row() == 1 | :ID != Lag( :ID ),
	lastCmtDate = .
);
If( :Comments != "",
	lastCmtDate = :Sampled Date
);
:Days Since Last Comment = (:Sampled Date - lastCmtDate) / In Days( 1 );

Re: Date Difference calculation referencing grouping columns

ktbrickey — Fri, 22 May 2020 12:12:19 GMT

Thanks ih, but this doesn't work. The new column you created is not populated with the date of the last comment, just the lag sampled date. Thanks for trying!

Re: Date Difference calculation referencing grouping columns

ktbrickey — Fri, 22 May 2020 12:14:24 GMT

Thank you! This worked!

Re: Date Difference calculation referencing grouping columns

voy-voy — Fri, 16 Feb 2024 08:54:39 GMT

I think I have a very simular problem.

I tried the formula you give us, but in my table it don't work. (column 5 (Differenz in Tagen Bauteil 1)).

At first it is write the day difference not in the rows wear the comment (1) is, rather in all other rows.

And more important for me, it's write just the difference to the last date, and not to the date where the last comment (or no comment) was.

Could you please help, again?

Re: Date Difference calculation referencing grouping columns

txnelson — Fri, 16 Feb 2024 11:59:37 GMT

Try this

If( Row() == 1 | :Source Table != Lag( :Source Table ),
	lastCmtDate = :"Datum:"n,
	lastCmtDate = Lag( :"Datum:"n )
);
If( :Bauteil 1 == "",
	:Differenz in Tagen Bauteil 1 = (:"Datum:"n - lastCmtDate) / In Days( 1 ),
	:Differenz in Tagen Bauteil 1 = .
);

Re: Date Difference calculation referencing grouping columns

voy-voy — Thu, 22 Feb 2024 10:56:50 GMT

Thank you Jim.

It is still not work, bu with your formulars I have found now a Work around and use 2 new colums to calculated and now it works :)

New Column( "Letzter Komentar Tag",
Numerisch,
"Stetig",
Format( "t.m.j", 12 ),
Eingabeformat( "t.m.j" ),
Formel(
If( Row() == 1 | :Quelltabelle != Lag( :Quelltabelle ),
lastCmtDate = .
);
If( :Bauteil 1 == "1",
lastCmtDate = :"Datum:"n,
lastCmtDate
)));

New Column( "Differenz Bauteil 1",
Numerisch,
"Stetig",
Format( "Bestes", 12 ),
Formel(
If( :Bauteil 1 == "1",
(:"Datum:"n - Lag( :Letzter Komentar Tag )) / In Days( 1 )
)));