[工学]SAS Workshop.ppt

SAS Data Management SAS Workshop SAS Data Management Outline INPUT Statement: Input Styles INFILE Statement PROC IMPORT/EXPORT Data Manipulation IF…ELSE DO…END Clauses Recode Variables LABEL and RENAME Variables Select Observations Variables Working with Data Sets SAS DATA SOURCES DATA STEP DATA steps read and manipulate data. INPUT tells how SAS reads data. DATALINES indicates data items to be read begin from the next line. INFILE reads data from an external file. LIBNAME sm ‘c:\temp\sas’; DATA sm.grade0; INPUT name $ id stat math; DATALINES; John 10091 89 95 … RUN; INPUT STATEMENT There are six input styles. List INPUT: simply list variable names Modified list INPUT: for ill-organized data Column INPUT: location of data items Formatted INPUT: format of data items Named INPUT: variable=data Mixed INPUT: combine input styles SAS recognizes styles automatically. List (previous slide), column, and formatted INPUT are commonly used. COLUMN INPUT Specify column locations of data items $ follows a character variable name Data should be aligned correctly Some data may be skipped (id below) DATA sm.grade1; INPUT name $ 1-6 stat 12-14 math 15-17; DATALINES; John 10091 89 95 Rachel10100 99 … RUN; FORMATTED INPUT Specify formats of data items. Data should be aligned correctly. $6. means a string 6 characters long. 3.0 or 3. means a 3 digit number without a decimal point. DATA sm.grade2; INPUT name $6. id 5. male 3. stat 3.0; DATALINES; John 10091 89 95 Rachel10100 99 … COLUMN CONTROLS @n moves the input pointer to the nth column. +n shifts the input pointer by n column to the right. You may skip some variables (e.g., id) INPUT name $6. +5 stat 3. @15 math 3.; DATALINES; John 10091 89 95 Rachel10100 99 … LINE CONTROLS @ and @@ trailing hold input records INPUT name $ stat math @@; DATALINES; John 89 95 Ron 76 100 #n moves the input pointer to nth line, / moves the input pointer to the next line INPUT name $6. #2 stat 3. / math 3.; DATALINES; John 89 95