I have a need to combine two sas datasets having the same column names but one of the datasets will have a numeric value where the same name in the other dataset are character. I was thinking to evaluate each field with the %isnum function and based on this convert the number to character:
char_id = put(id, 7.) ;
drop id ;
rename char_id=id ;
What I need to know is how do I determine the length of the variable to use in the PUT and what would I do for date fields?
Sounds like you need to analyze your data and see how long things are. Use an obviously too long format (best32.) and then see how long the actual results are, or use max.
For date fields, you need to decide how you want your date fields to look.
date_c = put(date_n,date9.);
That would be the default, but there are literally hundreds of date formats you can choose from.
You can also use proc contents data=myDataStes out=VarDatasets; run; and you will get the list of variables with type, length, format, informat and so on.
Related
Suppose I have in SAS someTable with a column someColumn of type Character.
I can adjust length, format, informat and label in the following way:
ALTER TABLE WORK.someTable
MODIFY someColumn char(8) format=$CHAR6. informat=$CHAR6. label='abcdef'
But I doubt if this is the correct way for the following reasons:
It seems pointless that the syntax requires the type char because column type can't be changed with a MODIFYstatement.
This code does not work if someColumn is of type Numeric or Date.
The syntax for changing length is inconsistent with the syntax for changing format/informat/label.
Actually, I expected the following code to work:
ALTER TABLE WORK.someTable
MODIFY someColumn length=8 format=$CHAR6. informat=$CHAR6. label='someLabel'
This code runs without errors nut does not change the length.
Question:
What is the correct syntax to modify the length of a column using ALTER TABLE / MODIFY?
(For arbitrary column type like character/numeric/date.)
The syntax for defining the altered variable ("column") is the same as the syntax PROC SQL uses for defining a variable. What the documentation calls "column-definition Component"
column data-type <column-modifier(s)>
That is why you use the SQL syntax, char(n) or num, for specifying the type. Note that SAS datasets only have two data types: fixed length character strings and floating point numbers. SAS will automatically convert any other SQL data-type into the proper one of those.
The limitations on altering the type are spelled out in the documentation:
Changing Column Attributes
If a column is already in the table, then
you can change the following column attributes by using the MODIFY
clause: length, informat, format, and label. The values in a table are
either truncated or padded with blanks (if character data) as
necessary to meet the specified length attribute.
You cannot change a character column to numeric and vice versa. To
change a column’s data type, drop the column and then add it (and its
data) again, or use the DATA step.
Note: You cannot change the length of a numeric column with the ALTER
TABLE statement. Use the DATA step instead.
Note that to make such changes to a dataset SAS will have to create a whole new dataset. So you might as well just write a data step to create the new dataset and then you will have full control.
Also be careful if you change the length of character variable to make sure that the attached FORMAT is still correct.
In your example you are changing the variable to be 8 bytes long, but are attaching a format that will only display the first 6 bytes.
In general it is best to not attach formats to character variables to avoid the confusion that type of mismatch can cause. Unfortunately there is no way to remove the attached format using PROC SQL. The best you could do is to set the format to $., that is without an explicit width. If you want to completely remove the format you will need to use a FORMAT statement in PROC DATASETS or a data step.
I have a table in SAS which contains the format information I want. I want to bin this data into the categories given.
What I don't know how to do is create either an xform or a format file from the data.
An example table looks like this:
TxtLabel Type FmtName label Hlo count
. I FAC1f 0 O 1
1996 I FAC1f 1 2
1997 I FAC1f 2 3
I want to date all years in a different data set as after 1997 OR before 1996.
The problem is that I know how to do this by hard coding it, but these files changes the numbers each time so I'm hoping to use the information in the table to generate the bins rather than hard code them.
How do I go about binning by data using a column from another dataset for my categorization?
Edit
I have two data sets, one which looks like the one I have included and one which has a column titled "YEAR". I want to bin the second data set using the categories from the first. In this case there are two available years in TxtLabel. There are multiple tables like this, I'm looking at how to generate PROC Format code from the table, rather than hard coding the values.
This should run to create the desired format
Proc FORMAT CNTLIN=MyCustomFormatControlData;
run;
You can then use it in a DATA Step, or apply it to a column in a data set.
Binning the data might be construed as 'data set splitting' but your question does not make it clear if that is so. Generic arbitrary splitting is often done with one of these techniques:
wall paper source code resolved from macro variables populated from information garnered in a Proc SQL or Proc FREQ step
dynamic data splitting using hash object for grouping records in memory, and saved to a data set with an .output() call.
Sample code for explicit binning
data want0 want1 want2 want3 want4 want5 wantOther;
set have;
* explicit wall paper;
select (put(year,FAC1f.));
when ('0') output want0;
when ('1') output want1;
when ('2') output want2;
when ('3') output want3;
when ('4') output want4;
when ('5') output want5;
otherwise output wantOther;
run;
This is the construct that source code generated by macro can produce, and requires
one pass to determine the when/output lines that are to be generated
a second pass to apply the lines of code that were generated.
If this is the data processing that you are attempting:
do some research (plenty of info out there)
write some code
make a new question if you get errors you can't resolve
Proc FORMAT
Proc FORMAT has a CNTLIN option for specifying a data set containing the format information. The structure and values expected of the Input Control Data Set (that CNTLIN) is described in the Output Control Data Set documentation. Some of the important control data columns are:
FMTNAME
specifies a character variable whose value is the format or informat name.
LABEL
specifies a character variable whose value is associated with a format or an informat.
START
specifies a character variable that gives the range's starting value.
END
specifies a character variable that gives the range's ending value.
As the requirements of the custom format to be created get more sophisticated you will need to have more information variables in the input control data set.
I have a data which is in one column which has a mix of all data types, formats.
text, numeric and also date.
I have to transpose the coloumn to rows.
When I import the data in to sas 9.3 the dates are turning into a number (char format) and after transpose when I try to convert using the input function it is not giving the correct date.
The observation I am getting is like 41172 in the date column.
How do I convert it?
Think you're confusing data types and formats. The two types are character and numeric.
Dates are all numeric, and are stored as a SASDATE which is the offset from 01 JAN 1960, with each day representing 1.
To have each SASDate be displayed, you must format that variable as a date (eg. date7, ddmmyy etc). That means you first need to use the input function to go from text to numeric (SASDate) then the put function to format it as you want it.
If you're using the input function, you just need to add one of those formats and a put function:
newvar=put(input(var,8.),date7.);
Or you could leave it as just the input() and use this:
format var date7.;
In your data step.
I have a huge table with a lot of columns.
I have numeric columns and character columns.
I need the sum of each numeric column and the max of each character column.
I need this row in a new DB
Is there a way to do it without write all varaible names?
By default, PROC MEANS will analyse all numeric variables if you leave out the VAR statement.
PROC MEANS data = work.example SUM;
RUN;
As far as I know, if you try to include character variables in a PROC MEANS it will not execute (see here).
If it's numeric values in character variables you're looking to retrieve the MAX of, perhaps consider using an INPUT function to convert them to numeric variables.
In test_1 table, the my_date field is a "DATE9." format.
I would like to convert it to a pure numeric format (number length 8) which is of the form YYYYMMDD.
I would also like to do this in a proc sql statement ideally.
Here's what I have so far.
Clearly I need something to manipulate the my_date field.
rsubmit;
proc sql;
CREATE TABLE test_2 AS
SELECT
my_date
FROM
test_1
;
quit;
endrsubmit;
FYI: I am finding it quite difficult to understand the various methods in SAS.
To clarify, the field should actually be a number, not a character field, nor a date.
If you want the field to store the value 20141231 for 31DEC2014, you can do this:
proc sql;
create table want as
select input(put(date,yymmddn8.),8.) as date_num
from have;
quit;
input(..) turns something into a number, put(..) turns something into a string. In this case, we first put it with your desired format (yymmddn8. is YYYYMMDD with no separator), and then input it with 8., which is the length of the string we are reading in.
In general, this should not be done; storing dates as numerics of their string representation is a very bad idea. Try to stay within the date formats, as they are much easier to work with once you learn them, and SAS will happily work with other databases to use their date types as well. If you want the "20141231" representation (to put it to a text file, for example), make it a character variable.
Don't.
You lose the ability to use built in SAS functions for date calculations.
SAS stores dates as numbers, 0 being Jan 1, 1960 and increments from there. Formats are used to display the formats as desired for reporting and presentation.