[R] problems with subset (misunderstanding somewhere)

Wladimir Eremeev wl at eimb.ru
Tue Apr 5 13:51:40 CEST 2005


Dear r-help,

I have the following function defined:

cubic.distance<-function(x1,y1,z1,x2,y2,z2) {
  max(c(abs(x1-x2),abs(y1-y2),abs(z1-z2)))
}

I have a data frame from which I make subsets.

When I call
  subset(dataframe,cubic.distance(tb19h,tb37v,tb19v,190,210,227)<=2)
I have the result with 0 rows.

However, the data frame contains the row (among others, that suit)
tb19v tb19h tb37v
226.6 189.3 208.4

Call
   cubic.distance(189.3,208.4,226.6,190,210,227)
gives
[1] 1.6

Next call:
> cubic.distance(189.3,208.4,226.6,190,210,227)<=2
[1] TRUE

It seems to me, that I have made errors somewhere in calls.
Could you, please, be so kind, to tell me, where they are?
Thank you.

--
Best regards
Wladimir Eremeev                                     mailto:wl at eimb.ru

==========================================================================
Research Scientist, PhD                           Leninsky Prospect 33,
Space Monitoring & Ecoinformation Systems Sector, Moscow, Russia, 119071,
Institute of Ecology,                             Phone: (095) 135-9972;
Russian Academy of Sciences                       Fax: (095) 135-9972




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