# [R] lapply problem

Luis Rideau Cruz Luisr at frs.fo
Fri Aug 13 13:40:24 CEST 2004

```R-help,

I wish to replace NULL elements(or missing) in the following list :
> z2
\$cod
mean       sd
62.56190 12.65452

mean       sd
36.61490 11.50365

\$ling
mean       sd
86.17949 20.43587

\$saithe
mean        sd
50.275847  5.453606

\$whiting
NULL

\$"norway pout"
mean        sd
13.739623  1.393104

\$"great silver smelt"
mean        sd
25.600000  1.549193

mean        sd
24.685225  3.902989

If I use
lapply(z2,function(x) ifelse(is.null(x),0,as.numeric(x)))

I get

> z2
\$cod
[1] 62.5619

[1] 36.6149

\$ling
[1] 86.17949

\$saithe
[1] 50.27585

\$whiting
[1] 0

\$"norway pout"
[1] 13.73962

\$"great silver smelt"
[1] 25.6

[1] 24.68522

i.e,only the first element in z2

And if I use

> z2<-lapply(msd.sumin.Z2S,function(x) ifelse(is.na(x),0,x))
Warning message:
is.na() applied to non-(list or vector) in: is.na(x)
> z2
\$cod
mean       sd
62.56190 12.65452

mean       sd
36.61490 11.50365

\$ling
mean       sd
86.17949 20.43587

\$saithe
mean        sd
50.275847  5.453606

\$whiting
logical(0)

\$"norway pout"
mean        sd
13.739623  1.393104

\$"great silver smelt"
mean        sd
25.600000  1.549193

mean        sd
24.685225  3.902989

which cannot be coreced to data frame(which is my aim)

How can it be resolve??

Thank you

Luis Ridao Cruz
Fiskirannsóknarstovan
Nóatún 1
P.O. Box 3051
FR-110 Tórshavn
Faroe Islands
Phone:             +298 353900
Phone(direct): +298 353912
Mobile:             +298 580800
Fax:                 +298 353901
E-mail:              luisr at frs.fo
Web:                www.frs.fo

```