topic Re: extract num variable from a date format weekv7. in New SAS User

extract num variable from a date format weekv7.

PierreYvesILY — Thu, 14 Jan 2021 17:11:37 GMT

hello dear SAS experts,

I use the following Code to select datalines by week:

%let Auswertungstag=%sysfunc(today());

Data zeitraum (keep=date);

format currdate yymmdd10. date weekv7. ;

Auswertungstag = &Auswertungstag.;

%kw(&Auswertungstag.);

Jahr = &Jahr1.;

currdate = input(cats(put(Jahr,z4.),'W',put(kw_kompakt,z2.)),weekv7.);

do date = currdate - 35 to currdate - 1 by 7;

output;

end;

run;

I get the results like this:

20W5001
20W5101
20W5201
20W5301
21W0101

I Need to extract the week number (1st. line: 50 ; 2nd line: 51 etc) and store it as a numeric value.

How can I proceed? I tried with substr(date,4,2) but it doesn't work.

Regards

Re: extract num variable from a date format weekv7.

Tom — Thu, 14 Jan 2021 17:23:34 GMT

What are you starting with?

Do you have the strings like '20W5001' ? If so then just pull out the '50' and use INPUT() to convert it to a number.

If you have something else then please provide a much clearer example of what is your input and what is your desired output. Your current code seems to have little relationship to your question.

string = '20W5001' ;
number = input(substr(string,4,2),32.);

Re: extract num variable from a date format weekv7.

ballardw — Thu, 14 Jan 2021 17:32:13 GMT

For any given actual date there are 3 different standard week number definitions that the Week function may use to get a week number. If the Date of interest that you have is using a WEEKV format then likely you need the Week function with the 'V' option to get a numeric value.

data example;
   format date   weekv7.;
   do date='01jan2021'd to '31dec2021'd;
      weeku = week(date,'u');
      weekv = week(date,'v');
      weekw = week(date,'w');
      output;
   end;
run;

Just to show the three possible "week" values from a given date.

Re: extract num variable from a date format weekv7.

PierreYvesILY — Thu, 14 Jan 2021 17:36:00 GMT

This doesn't work at all.

Re: extract num variable from a date format weekv7.

PierreYvesILY — Thu, 14 Jan 2021 17:45:26 GMT

I don't get the expected results, so I guess I'm not using the functions properly:

Data zeitraum (keep=date number weeku weekv weekw);

format currdate yymmdd10. date weekv7. ;

Auswertungstag = &Auswertungstag.;

%kw(&Auswertungstag.);

Jahr = &Jahr1.;

currdate = input(cats(put(Jahr,z4.),'W',put(kw_kompakt,z2.)),weekv7.);

do date = currdate - 35 to currdate - 1 by 7;

output;

end;

number = input(substr(string,4,2),32.);

weeku = week(date,'u');

weekv = week(date,'v');

weekw = week(date,'w');

run;

which gives the following result:

In Addition, the kw macro is the following:

%macro kw(datum);

/* datum1 ist immer ein Donnerstag, da nach DIN 1355 die erste KW die Woche ist, in

der mindestens 4 Tage des neuen Jahres sind, s. Link oben zu Wiki */

datum1=&datum-mod(&datum-mdy(1,1,1900),7)+3;

korrektur1=mod(&datum-mdy(1,1,1900),7)-10;

datum2=mdy(1,1,year(datum1))+korrektur1;

tage=&datum-datum2;

kwcalc=int(tage/7);

kw_kompakt=int((&datum-(mdy(1,1,year(&datum-mod(&datum-mdy(1,1,1900),7)+3))+(mod(&datum-mdy(1,1,1900),7)-10)))/7);

%mend kw;

Re: extract num variable from a date format weekv7.

ballardw — Thu, 14 Jan 2021 18:20:24 GMT

You have the WEEK functions AFTER the only output statement. So the values are not set when the data is written.

try

do date = currdate - 35 to currdate - 1 by 7;
   number = input(substr(string,4,2),32.);
   weeku = week(date,'u');
   weekv = week(date,'v');
   weekw = week(date,'w');
   output;
end;

Re: extract num variable from a date format weekv7.

PierreYvesILY — Fri, 15 Jan 2021 09:33:51 GMT

weekv is the good choice.

Re: extract num variable from a date format weekv7.

PierreYvesILY — Fri, 15 Jan 2021 12:30:38 GMT

Hello,

is there an analog way to extract the year?

20W5001 => 2020

regards

Re: extract num variable from a date format weekv7.

PierreYvesILY — Sat, 16 Jan 2021 06:50:13 GMT

Hello,

is there an analog way to extract the year?
20W5001 => 2020

Re: extract num variable from a date format weekv7.

Kurt_Bremser — Sun, 17 Jan 2021 10:44:28 GMT

For such a question, consult the documentation of SAS Functions and CALL Routines by Category .

Scroll down to the Date and Time section, and you will quickly find the YEAR Function.