DEXPORT and DIMPORT: DISPLAY MANAGER commands used to IMPORT and EXPORT the Tab delimited (Excel and .CSV) files;

One of my favorite methods of exporting excel or .csv file is to use the ‘DEXPORT’ command-line command. This certainly reduces the amount of typing required to export the SAS dataset. Another interesting point is DEXPORT command works fine in UNIX and PC.

Syntax: dm “DEXPORT libref.dsn 'filename.xls' replace;

"libref" is a library, "dsn" is the name of a SAS data set, and "filename.xls" is the name of the 

tab delimited text file(excel) being created. If we don’t specify the Libname or it is work then 

the dataset ‘dsn’ from the WORK directory is exported in a excel format to a specified location. 

Replace option … replaces the file if it already exists. 

Use DIMPORT command-line command to convert/import a tab delimited (excel or .csv etc) into a
SAS dataset.
Syntax: dm “DIMPORT ‘filename.csv’ exc" replace;

DIMPORT command tells SAS to import or convert the tab delimited file (filename.csv) to a SAS
dataset named ‘exc’; Replace option … replaces the dataset named ‘exc’ if it already exists by
any chance.

IFC and IFN functions: New IF functions:

Objective: To Reduce the amount of typing required achieving an objective

Syntax: IFN (condition, true, false, missing): ‘N’ stands for Numeric
IFN returns a numeric value. It returns the true, false or missing value depending on whether the condition is true, false or missing.

Syntax: IFC (condition, true, false, missing): ‘C’ stands for character
IFC function has four parameters:
1) a logical expression
2) character value returned when true
3) value returned when false
4) value retuned when missing, which is optional.

IFC (logical-expression, Character-value-returned-when-true, Character-value-returned-when-false, Character-value-returned-when-missing);
IFC returns a character value. It returns the true, false or missing value depending on whether the condition is true, false or missing.

Example: Assign a value to the VISIT variable (new) as per the VTYPE variable value.
We can certainly achieve this task in diff. ways.. here are they...

data old;
input sitesub $ vtype vdate $;
cards;
01-303 1.4 12/23/2005
01-304 1.5 09/03/2005
01-305 1.4 10/09/2005
01-306 1.5 11/17/2005
01-307 1.5 05/29/2005
01-308 . 04/30/2005
;
run;
1) * Using Proc Format:
proc format;
value vt
1.4='Baseline'
1.5='Retreat'
.='Missing'
;
run;
data new;
set old;
length visit $20;
visit=put(vtype,vt.);
run;

2) *Using the IF-THEN/ELSE statements;
data new;
set old;
length visit $20;
if vtype=1.4 then visit='Baseline';
else if vtype=1.5 then visit='Retreat';
else if vtype=. then visit='Missing';
run;

3) *Using the Proc SQL;
Proc sql;
Create table new4 as
Select *,
case
when vtype=1.4 then 'Baseline'
when vtype=1.5 then 'Retreat'
else 'Missing'
end as visit
from old;
Quit;

All three above methods required significant amount of typing when we compared with the below ones......
*Using the IFC function in Datastep;
data new;
set old;
length visit $20;
visit=ifc(vtype=1.4,'Baseline','Retreat','Missing');
run;

*Using the IFC function in Proc SQl;
Proc sql;
Create table new as
Select *,
Ifc(vtype=1.4,'Baseline','Retreat','Missing') as visit
from old;
Quit;
In a DATA step, if the IFC function returns a value to a variable that has not previously been assigned a length, then that variable is given a length of 200 bytes.

Note: IFN and IFN functions cannot be used if we want to assign more than 3 values (including missing) to a variable.