I have a dataframe which has four columns, I want to add a fifth column based on the values of an exisitng column, I want to add a column, let us name it "A", and the conditions should be like that, when angle =(0:90), so A=1, when angle =(180:270), so A=2, else, so A=NA
df
fromnode vianode tonode angle
36 1 120 140
36 3 56 190
40 67 145 75
40 33 43 250
. . . .
. . . .
345 185 456 290
so the final output should be like that
fromnode vianode tonode angle A
36 1 120 140 NA
36 3 56 190 2
40 67 145 75 1
40 33 43 250 2
. . . .
. . . .
345 185 456 290 NA
