r - How to calculate the amount of numbers inside a specific range -

i'm still having problems calculating numbers.

trying find amount of numbers inside [-0.5 , 0.5] first line, , amount of numbers outside same range in second line.

i use abc = rnorm(100, mean=0, sd=1). have 100 numbers in total, have 35 numbers inside range, , 35 outside range, dosen't add 100.

length(abc[abc>=-0.5 & abc<=0.5]) [1] 35  length(abc[abc<-0.5 & abc>0.5]) [1] 35 

then tried:

length(which(abc>=-0.5 & abc<=0.5)) [1] 40  length(which(abc<-0.5 & abc>0.5)) [1] 26 

and still doesn't add 100. what's wrong?

you after:

r> set.seed(1) r> abc = rnorm(100, mean=0, sd=1) r> length(abc[abc >= -0.5 & abc <= 0.5]) [1] 41 r> length(abc[abc < -0.5 | abc > 0.5]) [1] 59 

what went wrong

two things:

1. abc < -0.5 & abc > 0.5 asking values less -0.5 and greater 0.5

2. however, had: abc[abc<-0.5 & abc>0.5] bit different due scoping. let's pull apart:

   r> abc[abc<-0.5 & abc>0.5]  [1] 1.5953 0.7383 0.5758 1.5118 1.1249 0.9438 <snip> 

   now let's @ abc

   r> abc [1] false false false  true false false false   

   you've changed value of abc! because <- assignment operator. have set abc equal 0.5 & abc > 0.5. avoid this, use spacing (as in code).