topic Re: How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero in SAS/IML Software and Matrix Computations

How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero

desireatem — Sat, 02 Feb 2013 03:41:36 GMT

This is the code that I am using;

SurvivalM=J(nrow(survival1),1,1);

do i = 1 to n;

if censored=1 then SurvivalM=survival1; else if censored[1]=0 then SurvivalM=survival1; /*****Create a 1 by N -matrix of Survival ****/;

end;

print SurvivalM;

InverseC=J(nrow(survival1),1,1);

do i = 1 to n;

if censored=1 then InverseC=1/survival1; else if censored[1]=0 then InverseC=0; /*****survivalC is the imputed censored survival and set the real Survivalval to 1**/;

*InverseCC=J(nrow(survival1),1,1);

end;

print InverseC;

Big=SurvivalM*t(InverseC);

print BIG;

/*** for this code I want to delete all colums of BIG where row1 and col1 are zero ***/;

BIGG=J(nrow(BIGG),20,1);

do 1 to n;

if col[i,1]=0 then delete;

end;

print BIGG;

statement : ASSIGN at line 4338 column 1

4339 do 1 to n;

200

ERROR 22-322: Syntax error, expecting one of the following: a name, ;, DATA, UNTIL, WHILE.

ERROR 200-322: The symbol is not recognized and will be ignored.

4340 if col[i,1]=0 then delete;

4341 end;

ERROR: END does not occur within DO group at line=4341 col=1.

4342 print BIGG;

ERROR: Matrix BIGG has not been set to a value.

statement : PRINT at line 4342 column 1

Re: How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero

desireatem — Sat, 02 Feb 2013 04:10:31 GMT

I created this matrix BIG

ROW1	1.0875421	4.1015873
ROW2	1.030303	3.8857143
ROW3	1	3.7714286
ROW4	0.969697	3.6571429
ROW5	0.9090909	3.4285714
ROW6	0.8484848	3.2
ROW7	0.7878788	2.9714286
ROW8	0.7272727	2.7428571
ROW9	0.6666667	2.5142857
ROW10	0.6060606	2.2857143
ROW11	0.5454545	2.0571429
ROW12	0.4848485	1.8285714
ROW13	0.4242424	1.6
ROW14	0.3636364	1.3714286
ROW15	0.3030303	1.1428571
ROW16	0.2651515	1
ROW17	0.2272727	0.8571429
ROW18	0.1515152	0.5714286
ROW19	0.0757576	0.2857143
ROW20	0	0

and want to create another matrix BIGG by deleting all the colums that have first element equal zero in BIG to produce the matrix BIGG.

This is the wrong code;

SurvivalM=J(nrow(survival1),1,1);

do i = 1 to n;

if censored=1 then SurvivalM=survival1; else if censored[1]=0 then SurvivalM=survival1; /*****Create a 1 by N -matrix of Survival ****/;

end;

print SurvivalM;

InverseC=J(nrow(survival1),1,1);

do i = 1 to n;

if censored=1 then InverseC=1/survival1; else if censored[1]=0 then InverseC=0; /*****survivalC is the imputed censored survival and set the real Survivalval to 1**/;

*InverseCC=J(nrow(survival1),1,1);

end;

print InverseC;

Big=SurvivalM*t(InverseC);

print BIG;

/*** for this code I want to delete all colums of BIG where row1 and col1 are zero ***/;

BIGG=J(nrow(BIGG),20,1);

do 1 to n;

if col[i,1]=0 then delete;

end;

print BIGG;

statement : ASSIGN at line 4338 column 1

4339 do 1 to n;

200

ERROR 22-322: Syntax error, expecting one of the following: a name, ;, DATA, UNTIL, WHILE.

ERROR 200-322: The symbol is not recognized and will be ignored.

4340 if col[i,1]=0 then delete;

4341 end;

ERROR: END does not occur within DO group at line=4341 col=1.

4342 print BIGG;

ERROR: Matrix BIGG has not been set to a value.

statement : PRINT at line 4342 column 1

Re: How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero

IanWakeling — Sat, 02 Feb 2013 06:33:00 GMT

Use something like:

reduced=BIG[, loc( BIG[ 1,]^= 0 )];

so use the result of the loc function to pick out the list of columns required. The same technique can be used to remove zeros from the vector in one of your other questions.

Ian.

Re: How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero

Rick_SAS — Sat, 02 Feb 2013 22:26:43 GMT

Here is my advice: Your questions are all the same because you are working on a big problem. Do something easy like

u = 1:5;

v = {0,1,0,0,1};

Figure out how to do what you want with small vectors and matrices. After you understand the small simple case, the bigproblem will fall.

It will also make it easier for people on the discussion forum to answer your questions. A lot of people just hit the DELETE button if there isn't a short, simple, cut-an-paste example that illustrates the question.

Re: How to delete all columns where the col (x, 1)=0, that is the first number in the column is zero

desireatem — Sat, 02 Feb 2013 23:00:05 GMT

Thanks, it work