I hope someone can help. I have a large dataset imported to SAS with thousands of variables. I want to create a new dataset by extracting variables that have a specific keyword in their name. For example, the following variables are in my dataset:
AAYAN_KK_Equity_Ask
AAYAN_KK_Equity_Bid
AAYAN_KK_Equity_Close
AAYAN_KK_Equity_Date
AAYAN_KK_Equity_Volume
AAYANRE_KK_Equity_Ask
AAYANRE_KK_Equity_Bid
AAYANRE_KK_Equity_Close
AAYANRE_KK_Equity_Date
I want to extract variables that end with _Ask and _Bid without knowing the rest of the variable's name. Is there a way to do that? I want to try using a do loop but don't know how to instruct SAS to compare each variable's last part of the name with _Ask or _Bid.
Afterwords. I want to create a new variable for each set that starts with full name of the variable except the last part (Which is _Ask or _Bid). Can I do that in using an assignment statement?
You probably want to query sashelp.vtable which holds the metadata about your data set. Assuming your data is in the library WORK and called TABLE the following creates a list of the variables that end in ASK.
proc sql;
select name into :varlist separated by " "
from sashelp.vcolumn
where libname="WORK" and memname="TABLE" and upcase(name) like '%_ASK';
quit;
*To rename the variables with MID generate a rename statement;
proc sql;
select catx("=", name, tranwrd(upcase(name), "_ASK", "_MID"))
into :rename_list separated by " "
from sashelp.vcolumn
where libname="WORK" and memname="TABLE" and upcase(name) like '%_ASK';
quit;
%put &rename_list;
data want_ask;
set work.table
(keep = &varlist);
rename &rename_list;
run;
Related
I'm working on code that will change the coding of several hundred variables stored as 1/0 or Y/N in numeric 1 or 0. Because this will need to be in a flexible process, I am writing a macro to do so. The only issue that I am have with the macro is I am unable to pass the SAS column names to the macro to work. Thoughts?
%Macro Test(S,E);
%Array(A,&S.-&E.);
%MEnd;
data subset;
set dataset);
%Test(v1,v20)
run;
SAS supports variable lists. Macro parameters are just text strings. So as long as you use the macro variable value in a place where SAS supports variable lists there is no problem passing a variable list to a macro. For example here a simplistic macro to make an array statement.
%macro array(name,varlist);
array &name &varlist ;
%mend;
Which you could then use in the middle of a data step like this.
data want;
set have ;
%array(binary,var1-var20 a--d male education);
do over binary; binary=binary in ('Y','1','T'); end;
run;
The difficult part is if you want to convert variables from character to numeric then you will need to rename them. This will make it difficult to use variable lists (x1-x5 or vara -- vard). You can solve that problem with a little extra logic to convert the variable lists into a list of individual names. For example you can use PROC TRANSPOSE to create a dataset with the variable names that match your list.
proc transpose data=&inds(obs=0) out=_names ;
var &varlist;
run;
You could then use this dataset to generate code or generate a list of the individual variable names.
proc sql noprint ;
select name into :varlist2 separated by ' ' from _names;
quit;
A list of all variable names is stored in the dictionary.columns dataset. You can access it and store the names as a list that you can then loop through:
proc sql noprint;
select name into: list_of_names
separated by " "
from dictionary.columns where memname = upcase("your_dataset");
quit;
%put &list_of_names.;
I hope someone can help. I have a large dataset imported to SAS with thousands of variables. I want to create a new dataset by extracting variables that have a specific keyword in their name. For example, the following variables are in my dataset:
AAYAN_KK_Equity_Ask
AAYAN_KK_Equity_Bid
AAYAN_KK_Equity_Close
AAYAN_KK_Equity_Date
AAYAN_KK_Equity_Volume
AAYANRE_KK_Equity_Ask
AAYANRE_KK_Equity_Bid
AAYANRE_KK_Equity_Close
AAYANRE_KK_Equity_Date
I want to extract variables that end with _Ask and _Bid without knowing the rest of the variable's name. Is there a way to do that? I want to try using a do loop but don't know how to instruct SAS to compare each variable's last part of the name with _Ask or _Bid.
Afterwords. I want to create a new variable for each set that starts with full name of the variable except the last part (Which is _Ask or _Bid). Can I do that in using an assignment statement?
You probably want to query sashelp.vtable which holds the metadata about your data set. Assuming your data is in the library WORK and called TABLE the following creates a list of the variables that end in ASK.
proc sql;
select name into :varlist separated by " "
from sashelp.vcolumn
where libname="WORK" and memname="TABLE" and upcase(name) like '%_ASK';
quit;
*To rename the variables with MID generate a rename statement;
proc sql;
select catx("=", name, tranwrd(upcase(name), "_ASK", "_MID"))
into :rename_list separated by " "
from sashelp.vcolumn
where libname="WORK" and memname="TABLE" and upcase(name) like '%_ASK';
quit;
%put &rename_list;
data want_ask;
set work.table
(keep = &varlist);
rename &rename_list;
run;
Completely new to SAS here.
I have a data set with a huge amount of variables. I would like to extract all the variables that for example contains the string "GRP" within its name, and create a new data set from these variables.
EDIT: I do not know any of the variable names, as the data set is huge.
You can first store the variables you're interested into a macro variable and then use them in a keep list. Using data set name work.have as an example to create work.want:
/* note the use of use UPPERCASE */
proc sql noprint;
select name into :varlist separated by ' '
from dictionary.columns
where libname='WORK'
and memname='HAVE'
and upper(name) contains 'GRP'
;
quit;
/* keep only required variables */
data want;
set have(keep=&varlist);
run;
I have a SAS dataset which has 20 character variables, all of which are names (e.g. Adam, Bob, Cathy etc..)
I would like a dynamic code to create variables called Adam_ref, Bob_ref etc.. which will work even if there a different dataset with different names (i.e. don't want to manually define each variable).
So far my approach has been to use proc contents to get all variable names and then use a macro to create macro variables Adam_ref, Bob_ref etc..
How do I create actual variables within the dataset from here? Do I need a different approach?
proc contents data=work.names
out=contents noprint;
run;
proc sort data = contents; by varnum; run;
data contents1;
set contents;
Name_Ref = compress(Name||"_Ref");
call symput (NAME, NAME_Ref);
%put _user_;
run;
If you want to create an empty dataset that has variables named like some values you have in a macro variables you could do something like this.
Save the values into macro variables that are named by some pattern, like v1, v2 ...
proc sql;
select compress(Name||"_Ref") into :v1-:v20 from contents;
quit;
If you don't know how many values there are, you have to count them first, I assumed there are only 20 of them.
Then, if all your variables are character variables of length 100, you create a dataset like this:
%macro create_dataset;
data want;
length %do i=1 %to 20; &&v&i $100 %end;
;
stop;
run;
%mend;
%create_dataset; run;
This is how you can do it if you have the values in macro variable, there is probably a better way to do it in general.
If you don't want to create an empty dataset but only change the variable names, you can do it like this:
proc sql;
select name into :v1-:v20 from contents;
quit;
%macro rename_dataset;
data new_names;
set have(rename=(%do i=1 %to 20; &&v&i = &&v&i.._ref %end;));
run;
%mend;
%rename_dataset; run;
You can use PROC TRANSPOSE with an ID statement.
This step creates an example dataset:
data names;
harry="sally";
dick="gordon";
joe="schmoe";
run;
This step is essentially a copy of your step above that produces a dataset of column names. I will reuse the dataset namerefs throughout.
proc contents data=names out=namerefs noprint;
run;
This step adds the "_Refs" to the names defined before and drops everything else. The variable "name" comes from the column attributes of the dataset output by PROC CONTENTS.
data namerefs;
set namerefs (keep=name);
name=compress(name||"_Ref");
run;
This step produces an empty dataset with the desired columns. The variable "name" is again obtained by looking at column attributes. You might get a harmless warning in the GUI if you try to view the dataset, but you can otherwise use it as you wish and you can confirm that it has the desired output.
proc transpose out=namerefs(drop=_name_) data=namerefs;
id name;
run;
Here is another approach which requires less coding. It does not require running proc contents, does not require knowing the number of variables, nor creating a macro function. It also can be extended to do some additional things.
Step 1 is to use built-in dictionary views to get the desired variable names. The appropriate view for this is dictionary.columns, which has alias of sashelp.vcolumn. The dictionary libref can be used only in proc sql, while th sashelp alias can be used anywhere. I tend to use sashelp alias since I work in windows with DMS and can always interactively view the sashelp library.
proc sql;
select compress(Name||"_Ref") into :name_list
separated by ' '
from sashelp.vcolumn
where libname = 'WORK'
and memname = 'NAMES';
quit;
This produces a space delimited macro vaiable with the desired names.
Step 2 To build the empty data set then this code will work:
Data New ;
length &name_list ;
run ;
You can avoid assuming lengths or create populated dataset with new variable names by using a slightly more complicated select statement.
For example
select compress(Name)||"_Ref $")||compress(put(length,best.))
into :name_list
separated by ' '
will generate a macro variable which retains the previous length for each variable. This will work with no changes to step 2 above.
To create populated data set for use with rename dataset option, replace the select statement as follows:
select compress(Name)||"= "||compress(_Ref")
into :name_list
separated by ' '
Then replace the Step 2 code with the following:
Data New ;
set names (rename = ( &name_list)) ;
run ;
I want to remove columns/variables from a large SAS dataset, call it 'data'. I have all of the column names that I want to drop stored in another SAS dataset - let's call it 'var', it has a single column with header column. How do I drop all of the variables contained in 'var' from my original dataset 'data' with the drop function?
Thanks!
You can use the "into" clause of proc sql to copy the column of variable names from the "vars" data set into a macro variable that you then pass to the drop= statement in a data step. See below:
proc sql noprint;
select <name_of_column> into: vars_to_drop separated by " "
from var;
quit;
data data;
set data (drop= &vars_to_drop);
run;