table: problem with nan and if

[Uwe Brauer]

Hi

I have the following table 

#+begin_src elisp
#+NAME: test
| Name  | E1 | E2 |  E3 | Result1 | Result2 | Final |
|-------+----+----+-----+---------+---------+-------|
| User1 |    |    |     |         |       8 | nan    |
| User2 |    |    |     |         |         |        |
| User3 |  1 |  0 | 3.5 |     4.5 |     5.8 | 4.8    |
|-------+----+----+-----+---------+---------+-------|
#+TBLFM: $5=if(typeof(vsum($2..$4)) == 12, string(" "),vsum($2..$4));E 
f-1::$7=if("$6" == "nan", string(" "),0.3*$5+0.6*$6); E f-1
#+end_src

The calculations for User2 and 3 are fine, but for User1, the final
result is a  "nan".

I see the problem is caused by ; E f-1 I don't understand why because

As in 
#+begin_src elisp
| user1 | User2 |     |
|-------+-------+-----|
|       |     3 | nan |
|     0 |     1 | 0.8 |
#+TBLFM: $3=0.2*$1+0.8*$2; E f-1
#+end_src

I am not sure, but should I use something like 

if("$5" == "nan", string(" "),0.6*$6); E;f-1


But how can I combine both ifs, I am puzzled

Any  help is strongly appreciated.


Uwe Brauer