sample_name	group	x	y	a	b
#q2:types	categorical	numeric	numeric	numeric	numeric
sample01	aa	4	6	1	1
sample02	aa	5	9	2	2
sample03	aa	3	1	3	3
sample04	aa	5	3	4	5
sample05	aa	5	7	5	8
sample06	bb	2	4	1	10
sample07	bb	3	9	2	15
sample08	bb	3	3	3	20
sample09	bb	5	5	4	22
sample10	bb	4	3	5	27
sample11	bb	3	7	6	33
sample12	bb	5	5	7	36
sample13	bb	2	9	8	39
sample14	cc	4	7	1	40
sample15	cc	2	2	2	41
sample16	cc	4	4	3	43
sample17	cc	5	9	4	47
sample18	cc	1	2	5	50
sample19	cc	4	9	6	60