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06-25-2009 12:14 PM

Hello,

I am trying to tackle a problem in SAS. I have a dataset that has 1 row per ID. All of the rest of the variables are coded with a 0 or 1. What I am trying to do is flag if a member has 31 or more consecutive 0s. However, I only want to count the 0s that are in between each member’s first 1 and last 1.

Example #1: ID #1234’s first 1 is the variable Mar0900 and their last 1 is the variable Apr0900. This person does not have 31+ consecutive 0s in the variables between Mar0900 and Apr0900. Flag=N

Example #2: ID #2222’s first 1 is the variable Mar1000 and their last 1 is the variable Apr1500. This person has 31+ consecutive 0s in the variables between Mar1000 and Apr1500. Flag=Y

Example #3: ID #9876’s first 1 is the variable Apr0900 and their last 1 is the variable Apr1400. This person does not have 31+ consecutive 0s in the variables between Apr0900 and Apr1400. They do have 31+ consecutive 0s, but they happen before their first 1, therefore they do not count. Flag=N

Know of any code that I can use to do this? I would greatly appreciate any help in tackling this problem!

Thank you!

I am trying to tackle a problem in SAS. I have a dataset that has 1 row per ID. All of the rest of the variables are coded with a 0 or 1. What I am trying to do is flag if a member has 31 or more consecutive 0s. However, I only want to count the 0s that are in between each member’s first 1 and last 1.

Example #1: ID #1234’s first 1 is the variable Mar0900 and their last 1 is the variable Apr0900. This person does not have 31+ consecutive 0s in the variables between Mar0900 and Apr0900. Flag=N

Example #2: ID #2222’s first 1 is the variable Mar1000 and their last 1 is the variable Apr1500. This person has 31+ consecutive 0s in the variables between Mar1000 and Apr1500. Flag=Y

Example #3: ID #9876’s first 1 is the variable Apr0900 and their last 1 is the variable Apr1400. This person does not have 31+ consecutive 0s in the variables between Apr0900 and Apr1400. They do have 31+ consecutive 0s, but they happen before their first 1, therefore they do not count. Flag=N

Know of any code that I can use to do this? I would greatly appreciate any help in tackling this problem!

Thank you!

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06-25-2009 12:30 PM

Using a DATA step, setup an ARRAY declaring your variable list for the array contents. Using a DO/END loop and the DIM() function, work through the array variables and detect (using a temp SAS variable) your initial condition, then start counting (within the DO/END) until you reach the end of the array variable list -- you likely do not need to pass the variable list multiple times to establish the lowest/first and highest/last "1" condition/value, but that would depend on your DO/END loop code.

I suggest searching the SAS support website http://support.sas.com/ with some focus on SAS-hosted documentation and also supplemental technical/conference papers on ARRAY processing, and use DIM as a search keyword.

Scott Barry

SBBWorks, Inc.

I suggest searching the SAS support website http://support.sas.com/ with some focus on SAS-hosted documentation and also supplemental technical/conference papers on ARRAY processing, and use DIM as a search keyword.

Scott Barry

SBBWorks, Inc.

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06-25-2009 06:09 PM

As Scott mentioned you can acheive this by using arrays and Do loop. I have tried this for count >=4 then flag="Y". Try the below code if it fits for your requirement.

data test;

input id x1 x2 x3 x4 x5 x6 x7 x8 x9 x10;

cards;

101 1 0 0 0 0 0 1 0 0 0

102 0 0 0 0 0 0 1 0 0 0

103 1 0 0 0 0 0 0 0 0 0

104 1 0 0 1 0 0 0 0 0 1

105 1 0 0 1 0 0 0 0 1 0

;

run;

data test1;

set test;

by id notsorted;

array temp{*} x1-x10;

if first.id then do;

ss=0;

cnt=1;

end;

do i=1 to dim(temp)-1;

if temp(i)=1 then ss=1;

else if temp(i)=0 and ss=1 then do;

if temp(i+1)=1 then do;

cnt=cnt;

if cnt>=4 then do;

flag="Y";

cnt=1;

ss=0;

end;

end;

else if temp(i+1)=0 then cnt+1;

end;

end;

if flag='' then flag='N';

put _all_;

run;

~ Sukanya E

data test;

input id x1 x2 x3 x4 x5 x6 x7 x8 x9 x10;

cards;

101 1 0 0 0 0 0 1 0 0 0

102 0 0 0 0 0 0 1 0 0 0

103 1 0 0 0 0 0 0 0 0 0

104 1 0 0 1 0 0 0 0 0 1

105 1 0 0 1 0 0 0 0 1 0

;

run;

data test1;

set test;

by id notsorted;

array temp{*} x1-x10;

if first.id then do;

ss=0;

cnt=1;

end;

do i=1 to dim(temp)-1;

if temp(i)=1 then ss=1;

else if temp(i)=0 and ss=1 then do;

if temp(i+1)=1 then do;

cnt=cnt;

if cnt>=4 then do;

flag="Y";

cnt=1;

ss=0;

end;

end;

else if temp(i+1)=0 then cnt+1;

end;

end;

if flag='' then flag='N';

put _all_;

run;

~ Sukanya E

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06-25-2009 09:02 PM

Reusing Sukanya's data, you can also check this using character functions.

[pre]

data TEST;

input ID X1-X10;

STR=cats(of X1-X10); * create one string;

STR1=substr(STR,1,findc(STR,'1',-99)); * remove all zeroes after last 1;

FLAG=ifc(find(STR1,'0000',findc(STR1,'1')),'Y','N'); * look for 4 zeroes after 1st 1;

cards;

101 1 0 0 0 0 0 1 0 0 0

102 0 0 0 0 0 0 1 0 0 0

103 1 0 0 0 0 0 0 0 0 0

104 1 0 0 1 0 0 0 0 0 1

105 1 0 0 1 0 0 0 0 1 0

run;

[pre]

data TEST;

input ID X1-X10;

STR=cats(of X1-X10); * create one string;

STR1=substr(STR,1,findc(STR,'1',-99)); * remove all zeroes after last 1;

FLAG=ifc(find(STR1,'0000',findc(STR1,'1')),'Y','N'); * look for 4 zeroes after 1st 1;

cards;

101 1 0 0 0 0 0 1 0 0 0

102 0 0 0 0 0 0 1 0 0 0

103 1 0 0 0 0 0 0 0 0 0

104 1 0 0 1 0 0 0 0 0 1

105 1 0 0 1 0 0 0 0 1 0

run;