Re: [O] problem with empty column

[Uwe Brauer]

> > > "Eric" == Eric S Fraga <address@hidden> writes: 

   > On Friday,  5 Jan 2018 at 09:28, Uwe Brauer wrote: [...] 

   >> The last row behaves strangely the cell in the second 
   >> column is *not* empty but the cell in the third one is, 
   >> nevertheless the cell in the last column contains the 
   >> string nan, which I don't understand. 

   > But the second column is *not* empty; maybe you meant 3rd 
   > column? 

What I meant is this.

Take the following simple table

| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 | 10 | 30 | 40 | 50 | 
|| Entry2 | 10 | 20 | 30 | 40 |     | #+TBLFM: $6=($2+$3+$4+$5)/10 

C-u C-u C-c C-c
leads to 

| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 | 10 | 30 | 40 | 50 | 
|13 | Entry2 | 10 | 20 | 30 | 40 |  10 | #+TBLFM: 
|$6=($2+$3+$4+$5)/10 

Now for any new entry I want to have in the 6th column NP if the 
entry in the second column (not the whole column) is empty.

| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 | 10 | 30 | 40 | 50 | 
|13 | Entry2 | 10 | 20 | 30 | 40 |  10 | Entry3 |    |    |    | 
||     | 

Should lead to
| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 | 10 | 30 | 40 | 50 | 
|13 | Entry2 | 10 | 20 | 30 | 40 |  10 | Entry3 |    |    |    | 
||  NP | 


How can I achieve that?

The following works well

| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 |    |    |    |    | 
|NP  | Entry2 | 10 | 20 | 30 | 40 | 10  | #+TBLFM: $6=if("$2" == 
|"nan" , string("NP"),($2+$3+$4+$5)/10);E 

although the second column is *not* empty, but it is empty for 
Entry 1. 

But fails if there is a row like this


| Name   | E1 | E2 | E3 | E4 | Res | 
|--------+----+----+----+----+-----| Entry1 |    |    |    |    | 
|NP | Entry2 | 10 | 20 | 30 | 40 |  10 | Entry3 | 10 |    | 20 | 
|30 | nan | #+TBLFM: $6=if("$2" == "nan" , 
|string("NP"),($2+$3+$4+$5)/10);E 

Uwe