topic Column by index in Discussions

Column by index

IvanK — Sat, 10 Jun 2023 23:31:58 GMT

Hi!
What's the right way to reference a column by index? Ideally I was looking for something like this:

Thank you in advance!

Re: Column by index

jthi — Wed, 16 Jun 2021 19:32:06 GMT

You should be able to use just Column(index).

col = Column( 2 );     // assign a reference to the second column

Re: Column by index

IvanK — Wed, 16 Jun 2021 19:39:58 GMT

It may be true for scripts, but in formulas I get this error:

Interestingly, the popup suggests thatthe number can be provided, but it doesn't appear to be the case

Re: Column by index

jthi — Thu, 17 Jun 2021 11:54:18 GMT

Try with << get name instead of Column Name()

Choose(:Block, 
	Column(1) << get name, 
	Column(2) << get name, 
	Column(3) << get name
)

Full example:

Names Default To Here(1);


dt = New Table("Untitled",
	Add Rows(3),
	Compress File When Saved(1),
	New Column("Block", Numeric, "Continuous", Format("Best", 12), Set Values([1, 2, 3])),
	New Column("Column 2", Numeric, "Continuous", Format("Best", 12), Set Values([1, ., .])),
	New Column("Column 3", Numeric, "Continuous", Format("Best", 12), Set Values([2, ., .])),
	New Column("Column 4", Numeric, "Continuous", Format("Best", 12), Set Values([3, ., .])),
	New Column("Formula",
		Character,
		"Nominal",
		Formula(Choose(:Block, Column(1) << get name, Column(2) << get name, Column(3) << get name))
	)
);

Re: Column by index

IvanK — Thu, 17 Jun 2021 12:18:50 GMT

Thank you jthi, I feel like "<< get name" gets us one step forward. My final goal is to do a HLOOKUP basically, here's a demonstration. Currently it pulls the column name, while I want it to look at the data of that column.

Here's full code if needed:

New Table( "Untitled",
Add Rows( 3 ),
Compress File When Saved( 1 ),
New Column( "Column 1",
Numeric,
"Continuous",
Format( "Best", 12 ),
Set Values( [11, 111, 1111] )),
New Column( "Column 2",
Numeric,
"Continuous",
Format( "Best", 12 ),
Set Values( [22, 222, 2222] )),
New Column( "Column 3",
Numeric,
"Continuous",
Format( "Best", 12 ),
Set Values( [33, 333, 3333] )
),
New Column( "Block",
Numeric,
"Continuous",
Format( "Best", 12 ),
Set Values( [1, 2, 3] )
),
New Column( "Formula",
Character,
"Nominal",
Formula(
Choose( :Block,
Column( 1 ) << get name,
Column( 2 ) << get name,
Column( 3 ) << get name))))

Re: Column by index

jthi — Thu, 17 Jun 2021 12:31:25 GMT

Not exactly sure what data you want to get from the columns. Does Block column define the column and row for the cell you want to get the data from?

Column(:Block)[:Block]

Re: Column by index

brady_brady — Thu, 17 Jun 2021 14:17:26 GMT

Ah... I see what you want now.

Try this as your formula. It uses the format column(dt, n)[row()] to get the value in the current row, of the nth column of a data table, where the value of n is whatever you've placed in the current row of the :block column.

Column( :Block << get data table, :Block )[Row()]

Cheers,

Brady

Re: Column by index

IvanK — Thu, 17 Jun 2021 14:41:44 GMT

Thank you Brady, this is exactly what I was looking for. Much obliged!