Org mode: Simple "if" formula on my table throws an error

Question

I have a very simple table that looks like this:

| Fabricant | Catégorie | Animal                 | Nombre |
|-----------+-----------+------------------------+--------|
| Pearson   | Camp      | Bœuf                   |      1 |
| Pearson   |           | Castor                 |      1 |
| Pearson   |           | Chèvre                 |      2 |
| Pearson   |           | Cougar                 |      2 |

On which I apply this if formula as I have seen on the org mode documentation:

#+TBLFM: $5 = if($4 < 2, test, string(''))

But it throws an error:

| Fabricant | Catégorie | Animal                 | Nombre |        |
|-----------+-----------+------------------------+--------+--------|
| Pearson   | Camp      | Bœuf                   |      1 | #ERROR |
| Pearson   |           | Castor                 |      1 | #ERROR |
| Pearson   |           | Chèvre                 |      2 | #ERROR |
| Pearson   |           | Cougar                 |      2 | #ERROR |

I'm very new to Org mode, Emacs and spreadsheet formulas in general so I don't know what I'm doing wrong.

Answer 1

I don't know well the formula syntax for calc, but it seems that if you follow exactly the syntax of string constant that the documentation uses, it will work. Namely, replace '' by "":

#+TBLFM: $5 = if($4 < 2, test, string(""))

Can't explain why, though. There is also a formula syntax for Emacs Lisp that you might find more intuitive.

In your case, it translates to:

#+TBLFM: $5 = '(if (< (string-to-number $4) 2) "test" "")

which can be made shorter, as @gigiair pointed out, using N mode switch (all referenced elements will be numbers):

#+TBLFM: $5 = '(if (< $4 2) "test" ""); N

You might also find useful to toggle the formula debugger org-table-toggle-formula-debugger (C-c {) which would show you the expansion of the formula and an error message if applicable.