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Re: Pipedream lookup error in custom function

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On 13 Apr 2025 as I do recall,
          Richard Torrens (News)  wrote:

> In article <50d0090c5c.harriet@bazleyfamily.co.uk>,
>    Harriet Bazley <harriet@bazleyfamily.co.uk> wrote:

[snip]


> > I feel that it ought to be possible to have some kind of 'if' option
> > that would return zero if the lookup fails, but I can't work out a way
> > of doing it.)
> 
> > =================================
> 
> > Add up the total value of all the entries in array 2 which correspond to 
> > entries in array 1 that match one of the text values specified in this 
> > function. 
> > ------------------------------------------------------------------------
> > ...function("edibles","categories:array","prices:array")
> > ...lookup(C7,@categories,@prices)		Dairy
> > ...lookup(C8,@categories,@prices)		Greengrocery
> > ...lookup(C9,@categories,@prices)		Grocery
> > ...lookup(C10,@categories,@prices)		Meat
> > ...result(sum(A7A10))
> 
> I think you need to use dsum()
> 

Hmmm.  dsum() is what is creating these summary blocks in the first
place (listcount to analyse the categories present in a very long list,
then dsum() replicated downwards to add up the values corresponding to
each of those categories).

But I don't see how to use it to look up the numeric value in one array
corresponding to the textual value in a parallel array....
All I actually want to do here is to add up an arbitrary subset of the
values, but where I don't know in advance which values are necessarily
going to be present or which rows they are going to be located on -
since that depends on the output of listcount().

So I might have a block that looks like

Dairy	1	0.59
Entertainment	2	61.50
Greengrocery	5	64.95
Grocery	4	17.00
Household	1	5.00
Meat	3	12.60
Music	2	508.76
Postage	1	3.95
Repairs	2	271.00
Transport	1	3.50
Utilities	5	146.27

or one that looks like

Entertainment	1	10.00
Greengrocery	5	81.91
Grocery	3	11.00
Insurance	1	124.09
Meat	2	15.50
Music	2	110.00
Tax	1	226.85
Utilities	5	128.24

but I want to return the sum of the values for however many of Meat,
Dairy, Grocery and Greengrocery happen to be present.


-- 
Harriet Bazley                     ==  Loyaulte me lie ==

Sir Francis Drake circumcised the world with a 100-foot clipper.

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Pipedream lookup error in custom function Harriet Bazley <harriet@bazleyfamily.co.uk> - 2025-04-11 20:46 +0100
  Re: Pipedream lookup error in custom function "Richard Torrens (News) <News@Torrens.org> - 2025-04-13 11:42 +0100
    Re: Pipedream lookup error in custom function Harriet Bazley <harriet@bazleyfamily.co.uk> - 2025-04-13 18:14 +0100

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