Is there a state of the art in using org-tables as little databases with joins and stuff?
seems close, but not quite what I had in mind. I don't want to modify tables in place, or create dynamic tables. I do want to combine tables in memory though for subsequent calculations.
I was thinking more like given the tables from that page:
#+name: quantities
| type-1 | quty |
|----------+------|
| onion | 70 |
| tomatoe | 120 |
| eggplant | 300 |
| tofu | 100 |
#+name: nutrition
| type-2 | Fiber | Sugar | Protein | Carb |
|----------+-------+-------+---------+------|
| eggplant | 2.5 | 3.2 | 0.8 | 8.6 |
| tomatoe | 0.6 | 2.1 | 0.8 | 3.4 |
| onion | 1.3 | 4.4 | 1.3 | 9.0 |
| egg | 0 | 18.3 | 31.9 | 18.3 |
| rice | 0.2 | 0 | 1.5 | 16.0 |
| bread | 0.7 | 0.7 | 3.3 | 16.0 |
| orange | 3.1 | 11.9 | 1.3 | 17.6 |
| banana | 2.1 | 9.9 | 0.9 | 18.5 |
| tofu | 0.7 | 0.5 | 6.6 | 1.4 |
| nut | 2.6 | 1.3 | 4.9 | 7.2 |
| corn | 4.7 | 1.8 | 2.8 | 21.3 |
you would be able to do something like this:
#+BEGIN_SRC emacs-lisp
(join "quantities" "type-1" "nutrition" "type-2")
#+END_SRC
#+RESULTS:
| type-1 | quty | Fiber | Sugar | Protein | Carb |
|----------+------+-------+-------+---------+------|
| onion | 70 | 1.3 | 4.4 | 1.3 | 9.0 |
| tomatoe | 120 | 0.6 | 2.1 | 0.8 | 3.4 |
| eggplant | 300 | 2.5 | 3.2 | 0.8 | 8.6 |
| tofu | 100 | 0.7 | 0.5 | 6.6 | 1.4 |
or, to sum the Fiber column:
#+BEGIN_SRC emacs-lisp :var data="" "quantities" "type-1" "nutrition" "type-2")
(cl-loop for row in data sum (nth 2 row)))
#+END_SRC
#+RESULTS:
: 5.1000000000000005
I have spent a lot of time with Pandas in Python lately, and trying to think through what some analogues with org-tables would be. I would be very happy not to reinvent the wheel here!
John
-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803