I need to compare two data sets in terms of variable name, type, format, label (informat not provided in the data sets) in order to append and know the change across multiple years.
I know the options are PROC COMPARE and SQL comparison. But I want to control the output of comparison (then, SQL is preferred), and I am concerned about any change in format definition.
With SQL comparison, it's straightforward to compare variable name, type, label, variable format name.
For the two data sets I want to compare, the variable formats are defined by PROC FORMAT, codes saved separately in text files. Is there a way to compare format definition? It seems SAS can save format definition in a permanent/work? table. Is there a comparison available to compare format name, type, categories, variable the format is imposed on?
I'm a bit unclear what you're asking, but there are several options you can use to control the output from proc compare. Here's a couple that might be relevant to you, and you can always have a look at the documentation.
proc compare
base=one
compare=two
outbase /* Output rows which are in base table */
outcomp /* Output rows which are in comp table */
outdif /* Output differences between rows that are in both base and comp */
out=three /* Set table to send output to */
;
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 am trying to load SAS data file together with its variable and value labels, but I cant seem to make it work.
I have 3 SAS files
sas data ("data_final.sas7bdat")
sas format dictionary that contains the format name, variable name/labels, etc ("formats.sas7bdat")
sas format library that contains the format name, value name/labels,etc ("format_library.sas7bdat")
I am trying to load this to SPSS using the following code but it doesn't work. It loads the data and the variable labels but not the value labels.
GET SAS DATA='\data_final.sas7bdat'
/FORMATS='\formats.sas7bdat'
/FORMATS='\format_library.sas7bdat'.
Any help is greatly appreciated.
Thank you!
The FORMATS= option wants the name of the SAS format catalog, not another SAS dataset. Catalogs use sas7bcat as the extension.
GET SAS DATA='\data_final.sas7bdat'
/FORMATS='\formats.sas7bcat'.
If you really cannot get it to work then read in the formats_library.sas7bdat and look at the FMTNAME, TYPE, START, END and LABEL variables and use those to generate the SPSS code you need to attach data labels to your SPSS data.
FMTNAME is the name of the format. The TYPE determines if it is applies to character values or numeric values (or if in fact is an INFORMAT instead of FORMAT). The START and END mark the range of values (frequently they will be the same) and LABEL is the decoded value (aka the data label). Unlike in SPSS in SAS you only have to define the code/decode mapping once and then apply to as many variables as you want.
The dataset you show as being named formats.sas7bdat looks like it is the variable level metadata. That should list each variable (NAME) and what format, if any, has been attached to it (FORMAT). So if that shows there is a variable named FRED that has the format YESNO attached to it then look for records in format_library where FMTNAME='YESNO' and see what values it maps. So if FRED is numeric with values 1 and 2 then format YESNO might have one record with START='1' and LABEL='YES' and another with START='2' and LABEL='NO'.
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 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.
This might be a weird question. I have a data set contains data like agree, neutral, disagree...for many questions. There is not so many observations so for some question, one or more options has frequency of 0, say neutral. When I run proc freq, since neutral shows up in that variable, the table does not contain a row for neutral. I end up with tables with different number of rows. I would like to know if there is a option to show these 0 frequency rows. I will also need to run proc gchart for the same data set, and I will run into the same problem for having different number of bars. Please help me on this. Thank you!
This depends on how exactly you are running your PROC FREQ. It has the sparse option, which tells it to create a value for every logical cell on the table when creating an output dataset; normally, while you would have a cell with a missing value (or zero) in a crosstab, if that is output to a dataset (which is vertical, ie each combination of x and y axis value are placed in one row) those rows are left off. Sparse makes sure that doesn't happen; and in a larger (n-dimensional) crosstab, it creates rows for every possible combination of every variable, even ones that don't occur in the data.
However, if you're just doing
proc freq data=mydata;
tables myvar;
run;
That won't help you, as SAS doesn't really have anything to go on to figure out what should be there.
For that, you have to use a class variable procedure. Proc Tabulate is one of such procedures, and is similar to Proc Freq in its syntax (sort of). You need to either use CLASSDATA on the proc statement, or PRINTMISS on the table statement. In the former case, you do not need to use a format, I don't believe. In the latter case (PRINTMISS), you need to create a format for your variable (if you don't already have one) that contains all levels of the data that you want to display (even if it's just an identity format, e.g. formatting character strings to identical character strings), and specify PRELOADFMT on the proc statement. See this man page for more details.