topic How to extract submatrix? in SAS Programming

How to extract submatrix?

zana — Wed, 29 Oct 2014 17:17:48 GMT

Hello,

Currently i have problem for convert some submatrix from an output solution file. The one of output table (this output file contains 4000 table like as follows) is represented as the follows:

3.201	0.104	7.66	-6.77
-2.09	6.14	2.54	-1.06
0.36	2.36	-1.05	1.8
0.89	-0.36	-1.25	-0.08
1.20	2.36	0.65	-0.19
0.44	-0.47	0.54	1.25
-0.04	1.78	-0.15	1.36
0.13	-0.54	1.23	1.11

Please let me i show that as a simple way.

1	2	3	4
5	6	7	8
9	10	11	12
13	14	15	16
17	18	19	20
21	22	23	24
25	26	27	28
29	30	31	32

Now, i would like to create three submatrix (4*4) that they should be like these;

1st submatrix;

1	2	3	4
2	5	6	7
3	6	8	9
4	7	9	10

2nd submatrix;

11	12	13	14
12	15	16	17
13	16	18	19
14	17	19	20

and

...

How could i do it?

Many thanks!

Re: How to extract submatrix?

mohamed_zaki — Wed, 29 Oct 2014 19:05:30 GMT

What is formula or the method you want to use to extract the sub-matrix?

Re: How to extract submatrix?

CTorres — Wed, 29 Oct 2014 20:30:08 GMT

I assume that

3rd submatrix:

21	22	23	24
22	25	26	27
23	26	28	29
24	27	29	30

I also assume that table is a sas dataset:

data table;

input v1-v4;

cards;

3.201 0.104 7.66 -6.77

-2.09 6.14 2.54 -1.06

0.36 2.36 -1.05 1.8

0.89 -0.36 -1.25 -0.08

1.2 2.36 0.65 -0.19

0.44 -0.47 0.54 1.25

-0.04 1.78 -0.15 1.36

0.13 -0.54 1.23 1.11

;

run;

I developed the following solution that creates 3 SAS datasets: Submatrix1, Submatrix2 and Submatrix3:

data submatrix1(keep=colA:)
submatrix2(keep=colB:)
submatrix3(keep=colC:);
array vector(32);
array MatrixA(4,4);
array MatrixB(4,4);
array MatrixC(4,4);:

array ColA(4);
array ColB(4);
array ColC(4);
retain x 0;
do until (eof);
     set table end=eof;
     vector(x+1)=v1;
     vector(x+2)=v2;
     vector(x+3)=v3;
     vector(x+4)=v4;
     x+4;
end;
do i=1 to 4;
     do j=1 to 4;
        if min(i,j)=1 and (i=1 or j=1) then MatrixA(i,j)=max(i,j);
        else if min(i,j)=2 and (i=2 or j=2) then MatrixA(i,j)=i+j+1;
        else MatrixA(i,j)=i+j+2;
     end;
end;
do i=1 to 4;
     do j=1 to 4;
        MatrixB(i,j)=MatrixA(i,j)+10;
        MatrixC(i,j)=MatrixA(i,j)+20;
     end;
end;
do i=1 to 4;
     do j=1 to 4;
        n=MatrixA(i,j);
        colA(j)=vector(n);
        n=MatrixB(i,j);
        colB(j)=vector(n);
        n=MatrixC(i,j);
        colC(j)=vector(n);
     end;
     output submatrix1;
     output submatrix2;
     output submatrix3;
end;
run;

Is this what you need?

Re: How to extract submatrix?

zana — Wed, 29 Oct 2014 21:45:58 GMT

Thank you so much. For this example your code was true. Dear Torres, but when i try for another table file (rows=17; columns=7) it was more error. Please say me how can i run for this table (as follows).

1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30	31	32	33	34	35
36	37	38	39	40	41	42
43	44	45	46	47	48	49
50	51	52	53	54	55	56
57	58	59	60	61	62	63
64	65	66	67	68	69	70
71	72	73	74	75	76	77
78	79	80	81	82	83	84
85	86	87	88	89	90	91
92	93	94	95	96	97	98
99	100	101	102	103	104	105
106	107	108	109	110	111	112
113	114	115	116	117	118	.

For this table i need a program that extract submatrix as 8*8.

Thanks for your kind.

Re: How to extract submatrix?

CTorres — Thu, 30 Oct 2014 14:07:41 GMT

I do not understand the relation between the first matrix and the submatrixes you want to produce so you are right: Mi program does not work for the general case (witch I dont understand).

Anyway, I developed a Logic to populate any submatrix NxN from an initial value on. See this same entry in SAS/IML Software and Matrix computations.

CTorres

1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30	31	32	33	34	35
36	37	38	39	40	41	42
43	44	45	46	47	48	49
50	51	52	53	54	55	56
57	58	59	60	61	62	63
64	65	66	67	68	69	70
71	72	73	74	75	76	77
78	79	80	81	82	83	84
85	86	87	88	89	90	91
92	93	94	95	96	97	98
99	100	101	102	103	104	105
106	107	108	109	110	111	112
113	114	115	116	117	118	.

1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30	31	32	33	34	35
36	37	38	39	40	41	42
43	44	45	46	47	48	49
50	51	52	53	54	55	56
57	58	59	60	61	62	63
64	65	66	67	68	69	70
71	72	73	74	75	76	77
78	79	80	81	82	83	84
85	86	87	88	89	90	91
92	93	94	95	96	97	98
99	100	101	102	103	104	105
106	107	108	109	110	111	112
113	114	115	116	117	118	.

1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30	31	32	33	34	35
36	37	38	39	40	41	42
43	44	45	46	47	48	49
50	51	52	53	54	55	56
57	58	59	60	61	62	63
64	65	66	67	68	69	70
71	72	73	74	75	76	77
78	79	80	81	82	83	84
85	86	87	88	89	90	91
92	93	94	95	96	97	98
99	100	101	102	103	104	105
106	107	108	109	110	111	112
113	114	115	116	117	118	.