Re: table formula help...

[Michael Brand <michael.ch.brand@gmail.com>]

Hi Thierry

On Wed, Dec 10, 2014 at 11:55 PM, Thierry Banel <tbanelwebmin@free.fr> wrote:
> Le 10/12/2014 22:06, Michael Brand a écrit :
>> If this function would follow its docstring by having "(if (cdr vec)"
>> also for sum, min, max and prod then the user could benefit from
>> adding "E" and/or "N" or not in the mode string of the TBLFM:
>
> To further process the aggregations?

Yes, in the TBLFM of the result table.

> Here is how the spreadsheet handles those cases (without modifiers):
>   |   |   |   | sum |      mean | prod |
>   |---+---+---+-----+-----------+------|
>   | 1 | 2 | 3 |   6 |         2 |    6 |
>   |   | 2 | 3 |   5 | 1.6666667 |    6 |
>   |   |   | 3 |   3 |         1 |    3 |
>   |   |   |   |   0 |         0 |    1 | <--- see
>   #+TBLFM: $4=vsum($1..$3)::$5=vmean($1..$3)::$6=vprod($1..$3)

- Isn't the above table content from a different TBLFM with a mode
  string EN for vmean?:

  #+TBLFM: $4=vsum($1..$3)::$5=vmean($1..$3);EN::$6=vprod($1..$3)

- All columns without mode string (Org >= 8.0):

  |   |   |   | vsum |     vmean | vprod | vmin | vmax |
  |---+---+---+------+-----------+-------+------+------|
  | 1 | 2 | 3 |    6 |         2 |     6 |    1 |    3 |
  |   | 2 | 3 |    5 |       2.5 |     6 |    2 |    3 |
  |   |   | 3 |    3 |         3 |     3 |    3 |    3 |
  |   |   |   |    0 | vmean([]) |     1 |  inf | -inf |
  #+TBLFM: $4=vsum($1..$3)::$5=vmean($1..$3)::$6=vprod($1..$3)::$7=vmin($1..$3)::$8=vmax($1..$3)

- All columns with mode string EN (Org >= 8.0):

  |   |   |   | vsum |     vmean | vprod | vmin | vmax |
  |---+---+---+------+-----------+-------+------+------|
  | 1 | 2 | 3 |    6 |         2 |     6 |    1 |    3 |
  |   | 2 | 3 |    5 | 1.6666667 |     0 |    0 |    3 |
  |   |   | 3 |    3 |         1 |     0 |    0 |    3 |
  |   |   |   |    0 |         0 |     0 |    0 |    0 |
  #+TBLFM: $4=vsum($1..$3);EN::$5=vmean($1..$3);EN::$6=vprod($1..$3);EN::$7=vmin($1..$3);EN::$8=vmax($1..$3);EN

> This is correct. Orgaggregate should behave in a similar way.
> Fortunately in its latest version it does.

Ok, I see the similarity in the case for sum of "no input" with which
I now agree.

> * Summary
> Modifiers are lacking in orgaggregate for it to be fully consistent with
> the spreadsheet. If someone knowns how to add them easily...

I would try an approach like

#+TBLNAME: test
| Item | Value |
|------+-------|
| a    |       |
| a    |     2 |

#+BEGIN: aggregate :table test :cols ("Item" "2 * vsum(Value) + 3 *
vmean(Value); EN")
| Item | What column header here? How to specify? |
|------+------------------------------------------|
| a    |                                        7 |
#+END

that has a syntax more towards TBLFM with a Calc expression. It would
not need a mapping of the aggregation function like in
orgtbl-aggregate-apply-calc-*-function and would go through these
steps:

1) Collect list from aggregated input column "Value":

   => '("" "2")

2) Convert list to Calc vector depending on mode string, see also
   test-org-table/references/mode-string-EN and
   test-org-table/org-table-make-reference/mode-string-EN with their
   siblings:

   (org-table-make-reference '("" "2") t t nil) => "[0,2]"

3) Detach Calc expression from mode string and replace input header
   "Value" (possibly several and different input headers per output
   header) with Calc vector:

   "2 * vsum(Value) + 3 * vmean(Value); EN" =>
   "2 * vsum([0,2]) + 3 * vmean([0,2])"

4) Delegate everything else to Calc, just as org-table-eval-formula
   does:

   (calc-eval "2 * vsum([0,2]) + 3 * vmean([0,2])") => "7"

It is the same that happens already without orgaggregate as

| Value |
|-------|
|       |
|     2 |
|-------|
|     7 |
#+TBLFM: @>$1 = 2 * vsum(@I..@II) + 3 * vmean(@I..@II); EN

where the table formula debugger logs:

    Orig:   2 * vsum(@I..@II) + 3 * vmean(@I..@II)
    $xyz->  2 * vsum(@I..@II) + 3 * vmean(@I..@II)
    @r$c->  2 * vsum([0,2]) + 3 * vmean([0,2])
    $1->    2 * vsum([0,2]) + 3 * vmean([0,2])
    Result: 7

Mode strings other than "E" and "N" for orgaggregate should then not
be too far away, see also org-table-eval-formula.

Michael