dataframe - Using conditionals and summary functions in R mutate -

i have data frame in r looks

   v1 v2 v3 v4 animal  1  2  2  3  5  dog  2  2  4  3  1  dog  3  1  4  1  1  cat  4  5  5  1  3  cat  5  5  5  5  3  bird  6  3  3  3  4  bird 

where used group_by group data animal. created new column v6 takes column v4, divides lower values higher values, , if value smaller .5 have v6= , ifelse has v6 = b.. there way using mutate function conditional statement in r? actual data frame larger rather not have manually. final data frame

   v1 v2 v3 v4 animal v6  1  2  2  3  5  dog   2  2  4  3  1  dog   3  1  4  1  1  cat   4  5  5  1  3  cat   5  5  5  5  3  bird b  6  3  3  3  4  bird b 

and have started

df %>% mutate(type = if(min/max < .5)a,               ifelse, b) 

but know not correct. thank you!

using dplyr can try this

dat %>% group_by(animal) %>% mutate(new = ifelse(min(v4)/max(v4) < 0.5, "a", "b"))  #source: local data frame [6 x 6] #groups: animal  #  x1 v2 v3 v4 animal new #1  2  2  3  5    dog   #2  2  4  3  1    dog   #3  1  4  1  1    cat   #4  5  5  1  3    cat   #5  5  5  5  3   bird   b #6  3  3  3  4   bird   b