I have a list of values defined in a macro variable, e.g.,
%let datelist = 20100614 20120309 20151215;
Now, I want to put these values into the corresponding number of macro variables. In this case, I want to put them into Date1, Date2, Date3.
Of course, I could manually type out:
%let Date1 = 20100614;
%let Date2 = 20120309;
%let Date3 = 20151215;
How can I do that in a dynamic way so that if there were 25 dates, or 2, it would still work?
Ok, I'll suggest a data step, because I prefer that over macro loops any day.
Use COUNTW() to count the number of loops required and use CALL SYMPUTX to create the macro variables. You should look into the third parameter of the function if you want to control the scope of the macro variable.
%let datelist = 20100614 20120309 20151215;
data _null_;
word = "&datelist";
n=countw(word);
do i=1 to n;
call symputx('date'||Put(i, 8. -l), scan(word, i));
end;
run;
%put &date1.;
%put &date2.;
%put &date3.;
Related
I am processing a dataset, the contents of which I do not know in advance. My target SAS instance is 9.3, and I cannot use SQL as that has certain 'reserved' names (such as "user") that cannot be used as column names.
The puzzle looks like this:
data _null_;
set some.dataset; file somefile;
/* no problem can even apply formats */
put name age;
/* how to do this without making new vars? */
put somefunc(name) max(age);
run;
I can't put var1=somefunc(name); put var1; as that may clash with a source variable named var1.
I'm guessing the answer is to make some macro function that will read the dataset header and return me a "safe" (non-clashing) variable, or an fcmp function in a format, but I thought I'd check with the community to see - is there some "old school" way to outPUT directly from a function, in a data step?
Temporary array?
34 data _null_;
35 set sashelp.class;
36 array _n[*] _numeric_;
37 array _f[3] _temporary_;
38 put _n_ #;
39 do _n_ = 1 to dim(_f);
40 _f[_n_] = log(_n[_n_]);
41 put _f[_n_]= #;
42 end;
43 put ;
44 run;
1 _f[1]=2.6390573296 _f[2]=4.2341065046 _f[3]=4.7229532216
2 _f[1]=2.5649493575 _f[2]=4.0342406382 _f[3]=4.4308167988
3 _f[1]=2.5649493575 _f[2]=4.1789920363 _f[3]=4.5849674787
4 _f[1]=2.6390573296 _f[2]=4.1399550735 _f[3]=4.6298627986
5 _f[1]=2.6390573296 _f[2]=4.1510399059 _f[3]=4.6298627986
6 _f[1]=2.4849066498 _f[2]=4.0483006237 _f[3]=4.4188406078
7 _f[1]=2.4849066498 _f[2]=4.091005661 _f[3]=4.4367515344
8 _f[1]=2.7080502011 _f[2]=4.1351665567 _f[3]=4.7229532216
9 _f[1]=2.5649493575 _f[2]=4.1351665567 _f[3]=4.4308167988
The PUT statement does not accept a function invocation as a valid item for output.
A DATA step does not do columnar functions as you indicated with max(age) (so it would be even less likely to use such a function in PUT ;-)
Avoid name collisions
My recommendation is to use a variable name that is highly unlikely to collide.
_temp_001 = somefunc(<var>);
_temp_002 = somefunc2(<var2>);
put _temp_001 _temp_002;
drop _temp_:;
or
%let tempvar = _%sysfunc(rand(uniform, 1e15),z15.);
&tempvar = somefunc(<var>);
put &tempvar;
drop &tempvar;
%symdel tempvar;
Repurpose
You can re-purpose any automatic variable that is not important to the running step. Some omni-present candidates include:
numeric variables:
_n_
_iorc_
_threadid_
_nthreads_
first.<any-name> (only tweak after first. logic associated with BY statement)
last.<any-name>
character variables:
_infile_ (requires an empty datalines;)
_hostname_
avoid
_file_
_error_
I think you would be pretty safe choosing some unlikely to collide names. An easy way to generate these and still make the code somewhat readable would be to just hash a string to create a valid SAS varname and use a macro reference to make the code readable. Something like this:
%macro get_low_collision_varname(iSeed=);
%local try cnt result;
%let cnt = 0;
%let result = ;
%do %while ("&result" eq "");
%let try = %sysfunc(md5(&iSeed&cnt),hex32.);
%if %sysfunc(anyalpha(%substr(&try,1,1))) gt 0 %then %do;
%let result = &try;
%end;
%let cnt = %eval(&cnt + 1);
%end;
&result
%mend;
The above code takes a seed string and just adds a number to the end of it. It iterates the number until it gets a valid SAS varname as output from the md5() function. You could even then test the target dataset name to make sure the variable doesn't already exist. If it does build that logic into the above function.
Test it:
%let my_var = %get_low_collision_varname(iSeed=this shouldnt collide);
%put &my_var;
data _null_;
set sashelp.class;
&my_var = 1;
put _all_;
run;
Results:
Name=Alfred Sex=M Age=14 Height=69 Weight=112.5 C34FD80ED9E856160E59FCEBF37F00D2=1 _ERROR_=0 _N_=1
Name=Alice Sex=F Age=13 Height=56.5 Weight=84 C34FD80ED9E856160E59FCEBF37F00D2=1 _ERROR_=0 _N_=2
This doesn't specifically answer the question of how to achieve it without creating new varnames, but it does give a practical workaround.
I have 5 separate datasets(actually many more but i want to shorten the code) named dk33,dk34,dk35,dk51,dk63, each dataset contains a numeric field: surv_probs. I would like to load the values into 5 arrays and then use the arrays in a datastep(result), however, I need advice what is the best way to do it.
I am getting error when I use the macro: setarrays: (code below)
WARNING: The quoted string currently being processed has become more than 262 characters long. You might have unbalanced quotation
marks.
WARNING: The quoted string currently being processed has become more than 262 characters long. You might have unbalanced quotation
marks.
ERROR: Illegal reference to the array dk33_arr.
Here is the main code.
%let var1 = dk33;
%let var2 = dk34;
%let var3 = dk35;
%let var4 = dk51;
%let var5 = dk63;
%let varN = 5;
/*put length of each column into macro variables */
%macro getlength;
%do i=1 %to &varN;
proc sql noprint;
select count(surv_probs)
into : &&var&i.._rows
from work.&&var&i;
quit;
%end;
%mend;
/*load values of column:surv_probs into macro variables*/
%macro readin;
%do i=1 %to &varN;
proc sql noprint;
select surv_probs
into: &&var&i.._list separated by ","
from &&var&i;
quit;
%end;
%mend;
data _null_;
call execute('%readin');
call execute('%getlength');
run;
/* create arrays*/
%macro setarrays;
%do i=1 %to 1;
j=1;
array &&var&i.._arr{&&&&&&var&i.._rows};
do while(scan("&&&&&&var&i.._list",j,",") ne "");
&&var&i.._arr = scan("&&&&&&var&i.._list",j,",");
j=j+1;
end;
%end;
%mend;
data result;
%setarrays
put dk33_arr(1);
* some other statements where I use the arrays*
run;
Answer to toms question:
*macro getlength(when executed) creates 5 macro variables named: dk33_rows,dk34_rows,dk35_rows,dk51_rows,dk63_rows
*the macro readin(when executed):creates 5 macro variables dk33_list,dk34_list,dk35_list,dk51_list,dk63_list. Each containing a string which is comma separates the values from the column: eg.: 0.99994,0.1999,0.1111
*the macro setarrays creates 5 arrays,when executed, dk33_arr,dk34_arr,... holding the parsed values from the macro variables created by readin
I find that "macro arrays" like VAR1,VAR2,.... are generally more trouble than they are worth. Either keep your list of dataset names in an actual dataset and generate code from that. Or if the list is short enough put the list into a single macro variable and use %SCAN() to pull out the items as you need them.
But either way it is also better to avoid trying to write macro code that needs more than three &'s. Build up the reference in multiple steps. Build a macro variable that has the name of the macro you want to reference and then pull the value of that into another macro variable. It might take more lines of code, but you can more easily understand what is happening.
%let i=1 ;
%let mvarname=var&i;
%let dataset_name=&&&mvarname;
Before you begin using macro code (or other code generation techniques) make sure you know what code you are trying to generate. If you want to load a variable into a temporary array you can just use a DO loop. There is no need to macro code, or copying values, or even counts, into macro variables. For example instead of getting the count of the observations you could just make your temporary array larger than you expect to ever need.
data test1 ;
if _n_=1 then do;
do i=1 to nobs_dk33;
array dk33 (1000) _temporary_;
set dk33 nobs=nobs_dk33 ;
dk33(i)=surv_probs;
end;
do i=1 to nobs_dk34;
array dk34 (1000) _temporary_;
set dk34 nobs=nobs_dk34 ;
dk34(i)=surv_probs;
end;
end;
* What ever you are planning to do with the DK33 and DK34 arrays ;
run;
Or you could transpose the dataset first.
proc transpose data=dk33 out=dk33_t prefix=dk33_ ;
var surv_probs ;
run;
Then your later step is easier since you can just use a SET statement to read in the one observation that has all of the values.
data test;
if _n_=1 then do;
set dk33_t ;
array dk33 dk33_: ;
end;
....
run;
I create a marco array using:
proc sql;
select distinct variable into:numVarList separated by ' ' from Map_num;
I used:
%put &numVarList{1};
and it gave me all variables:var1 var2 var3{1}
how to use index to pick out macro array variable?
update 20180305
it is strange that
%put &numVarList.;
then I got:age agenc_non_ccbt_fnd_bal chmtpd_tmpnt_bal crnyr_cnter_tdnum
%put %sysnc(scan(&numVarList.,1,str( )));
I got:age agnc_non_ccb
why?and how to fix it?
You do not create an array with your select. The result is just a string: var1 var2 var3
However you can access each element with the scan-function:
%let first_ele = %scan(&numVarList.,1,%str( ));
The result is: var1
You can also loop your string like this:
%do i=1 %to %sysfunc(countw(&numVarList.,%str( )));
%put %scan(&numVarList.,&i.,%str( ));
%end;
Concatenation of values
proc sql;
select distinct variable into:numVarList separated by ' ' from Map_num;
populates a single macro variable with a value, that can be construed as a list, which is a concatenation of the distinct values in the column named "variable".
For such a list you would scan out the individual items as shown by #zuluk.
In your case when the original values are names of variables, the resolution of the concatenation can be used directly as part of a SAS statement that accepts variable name lists, such as Proc PRINT; VAR &numVarList or DATA _NULL_; ARRAY v &numVarList
Macro array
The concept macro-array is simply a set of macro variables (which can be thought of as 'symbols' when too many 'variable' ideas are colliding) with a common basename and increasing numeric suffix. Such a set of macro variables is created by using a slightly different syntax in Proc SQL.
select distinct variable
into :symbol1-:symbol9999
from Map_num
The 9999 represents a large number that you do not expect to exceed. If the data has N <= 9999 rows then only N macro variable will be created. If N > 9999 rows only 9999 macro variables will be created. Caution: Too many macro variables can fill the macro symbol table and cause errors in your SAS. For me, Macro arrays are more a programming concept than a programming construct.
For example
Proc SQL noprint;
select name into :name1-:name9999 from sashelp.class;
%let name_count = &sqlobs;
quit;
%put NOTE: &=name1;
%put NOTE: &=name2;
%put NOTE: name&name_count=%superq(name&name_count); * almost same as next;
%put NOTE: name&name_count=&&name&name_count; * almost same as prev;
When dealing with the 'name' of the macro array in 1-level abstraction way, complete resolution is achieved by coding the 'tricky triple-hat' &&&
%macro log_macroArray (basename);
%local i count_symbol value_symbol;
%let count_symbol = &basename._count;
%do i = 1 %to &&&count_symbol;
%let value_symbol = &basename.&i;
%put NOTE: &value_symbol=&&&value_symbol;
%end;
%mend;
%log_macroArray(name);
The SAS macro system 'loops' internally during its value resolution phase and collapses the presence to && to & at each step of it's internal evaluation.
Building on #zuluk's answer, you cannot use an operator (like { }) to access a macro "array" since it's not a part of the language and it's not possible to overload operators in SAS... mostly ... but you can do a function-style macro easily.
proc sql;
select name into :namelist separated by ' '
from sashelp.class;
quit;
%macro marray(list, n);
%scan(&list.,&n.)
%mend marray;
%put %marray(&namelist,2);
That is pretty close to what you're looking for, just not quite the same syntax. If you then wanted to build new variables/etc., you could do so through the macro as well, though it might be more complicated to write a general macro given there are lots of ways you might want to do that. Here's a non-function-style version.
%macro m_to_array(list, n);
*optionally - if you want to not specify n;
%let n = %sysfunc(countw(&&&list));
%do _i = 1 %to &n;
%global &list.&_i.;
%let &list.&_i. = %scan(&&&list.,&_i.);
%end;
%mend m_to_array;
%m_to_array(namelist);
%put _global_;
below is my little problem to create a macro and passing in a date variable. Without using the date variable, it works with results as below.
%macro x();
%let i=-1;
%let dts = %sysfunc(today());
%put &dts; /*ok*/
%let yymm1 = %sysfunc(intnx(MONTH,&dts,&i));
%put &yymm1; /*ok*/
%let mth_beg = %sysfunc(intnx(MONTH,&dts,&i,B),date9.);
%let mth_end = %sysfunc(intnx(MONTH,&dts,&i,E),date9.);
%put &mth_beg &mth_end; /*01JAN2018 31JAN2018*/
/*** proc sql code below ** */
%mend;
%x();
log:
21231
21185
01JAN2018
31JAN2018
Now I create a macro around it and got the following error:
%macro x(dts1);
%let i=-1;
/*%let dts = %sysfunc(today());*/
%let dts = %sysfunc(&dts1);
%put &dts; /*ok*/
%let yymm1 = %sysfunc(intnx(MONTH,&dts,&i));
%put &yymm1; /*ok*/
%let mth_beg = %sysfunc(intnx(MONTH,&dts,&i,B),date9.);
%let mth_end = %sysfunc(intnx(MONTH,&dts,&i,E),date9.);
%put &mth_beg &mth_end; /*01JAN2018 31JAN2018*/
/*** proc sql code below ** */
%mend;
%x(16JAN2018);
ERROR: Function name missing in %SYSFUNC or %QSYSFUNC macro function reference.
JAN2018)
ERROR: Expected close parenthesis after macro function invocation not found.
))
ERROR: Expected close parenthesis after macro function invocation not found.
ERROR: Expected close parenthesis after macro function invocation not found.
,B),date9.) ,E),date9.)
I am not sure how to let SAS treat the date passed in as a recognized date. I know i probably used the sysfunc(&dts) wrongly or the date passed in need to adhere to certain format. i just want the date to replace today(). Can you help? I am a SAS newbie.
thanks
Wrap the date in " and end with a d. That will tell SAS to convert the string to a date:
%macro x(dts1);
%let i=-1;
/*%let dts = %sysfunc(today());*/
%let dts = "&dts1"d; /*Change here!*/
%put &dts; /*ok*/
%let yymm1 = %sysfunc(intnx(MONTH,&dts,&i));
%put &yymm1; /*ok*/
%let mth_beg = %sysfunc(intnx(MONTH,&dts,&i,B),date9.);
%let mth_end = %sysfunc(intnx(MONTH,&dts,&i,E),date9.);
%put &mth_beg &mth_end; /*01JAN2018 31JAN2018*/
/*** proc sql code below ** */
%mend;
%x(16JAN2018);
change %let dts = %sysfunc(&dts1); to
%let dts = %sysfunc(inputn(&dts1,date9. ));
SAS stores dates as the number of days since 01JAN1960. So if you do not attach a date format to the date value it will just look like an integer.
%let today=%sysfunc(today());
You can then use that integer anywhere you would use a date value.
%let next_month=%sysfunc(intnx(month,&today,1,b));
You can also represent dates by using a date literal. To make a date literal you represent the date value using something the DATE informat can read (like 16FEB2018, 16feb18, 16-FEB-2018, etc.) enclosed in quotes with the letter d appended.
%let today="%sysfunc(today(),date9)"d ;
%let date_string=13FEB2018;
%let date_value="&date_string"d ;
So date literals will work in SAS code and when you use the %sysfunc() macro function to call a SAS function (like INTNX) and they will work in the %sysevalf() macro function. But the %eval() macro function will not recognize date literals. So you will need to use %sysevalf() if you want use arithmetic or comparisons of date literals in macro logic.
%if %sysevalf(&today > '01JAN2018'd) %then ....
%let tomorrow=%sysevalf(&today +1);
How do I print out the data type of a macro variable in the log
%macro mymacro(dt2);
%LET c_mth = %SYSFUNC(intnx(month,&dt2.d,-1,e),date9.) ;
%put &c_mth;
%mend;
mymacro('01sep2014')
I have a bunch of macro variables assigned using a %let or into:
my problem is I'm trying to do a bunch of boolean condition on dates but I suspect that some of my variables are strings and some are dates
I have casted them in my code but to triple check there is surely a way to return something to the log
I want something similar to using str() or mode() or is.numeric() in R
H,
The SAS macro language is weird. : )
As Reeza said, macro variables do not have a type, they are all text.
But, if you use Boolean logic (%IF statement), and both operands are integers, the macro language will do a numeric comparison rather than a character comparison.
So you can use the INPUTN() function to convert the date strings to SAS dates (number of days since 01Jan1960), and then compare those. Here's an example, jumping off from your code:
%macro mymacro(dt1,dt2);
%local c_mth1 c_mth2 n_mth1 n_mth2;
%let c_mth1 = %sysfunc(intnx(month,&dt1.d,-1,e),date9.) ;
%let c_mth2 = %sysfunc(intnx(month,&dt2.d,-1,e),date9.) ;
%let n_mth1 = %sysfunc(inputn(&c_mth1,date9.)) ;
%let n_mth2 = %sysfunc(inputn(&c_mth2,date9.)) ;
%put &c_mth1 -- &n_mth1;
%put &c_mth2 -- &n_mth2;
%if &n_mth1<&n_mth2 %then %put &c_mth1 is before &c_mth2;
%else %put &c_mth1 is NOT before &c_mth2;
%mend;
Log from a sample call:
236 %mymacro('01feb1960','01mar1960')
31JAN1960 -- 30
29FEB1960 -- 59
31JAN1960 is before 29FEB1960
--Q.
Macro variables do not have a type, they are all text.
You have to make sure the variable is passed in a way that makes sense to the program and generates valid SAS code.
%let date1=01Jan2014;
%let date2=31Jan2014;
data _null_;
x = "&date1"d > "&date2"d;
y = "&date2"d > "&date1"d;
z = "&date2"d-"&date1"d;
put 'x=' x;
put 'y=' y;
put 'z=' z;
run;
Log should show:
x=0
y=1
z=30
If your macro variables resolve to date literals, you can use intck combined with %eval to compare them, e.g.
%let mvar1 = '01jan2015'd;
%let mvar2 = '01feb2015'd;
/*Prints 1 if mvar2 > mvar1*/
%put %eval(%sysfunc(intck(day,&mvar1,&mvar2)) > 0);