[R] match() & seq()

[Jacques VESLOT]

sorry if it has already been discussed but i can't understand this:

 > seq(0.1,1,by=0.1)
 [1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
 > match(0.1,seq(0.1,1,by=0.1))
[1] 1
 > match(0.2,seq(0.1,1,by=0.1))
[1] 2
 > match(0.3,seq(0.1,1,by=0.1))
[1] NA
 > match(0.4,seq(0.1,1,by=0.1))
[1] 4

 > R.version
         _             
platform i386-pc-mingw32
arch     i386          
os       mingw32       
system   i386, mingw32 
status                 
major    2             
minor    2.1           
year     2005          
month    12            
day      20            
svn rev  36812         
language R