say that I have a vector a_vector = c('a', 'b', 'c', 'd').
How could I get different combinations of all characters in a_vector in R.
The expected output is below.
a_vector = c('a', 'b', 'c', 'd')
r1 = 'a'
r2 = 'b'
r3 = 'c'
r4 = 'd'
r5 = c('a', 'b')
r6 = c('a', 'c')
r7 = c('a', 'd')
r8 = c('b', 'c')
r9 = c('b', 'd')
r10= c('c', 'd')
r11= c('a', 'b', 'c')
r12= c('a', 'b', 'd')
r13= c('b', 'c', 'd')
r14= c('a', 'c', 'd')
r15= c('a', 'b', 'c', 'd')
final_result = list(r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15)