Introduction to SAS Programs. Objectives. SAS Programs. Sample Data. File Containing Data: boxhunter.dat

Transcription

1 Introduction to Statistical omputing SS, Minitab, and xcel Simple ata ntry and asic Reporting 1.1 Introduction to SS Programs 1.2 Introduction to Minitab Programs 1.3 Introduction to xcel Spreadsheets 1.4 asic Instructions for SS, Minitab and xcel 1.5 MO xcel 1.6 MO Minitab 1.7 MO SS Introduction to SS Programs 1 Objectives State the components of a SS program and how SS programs are executed in the windowing environment. efine the components of a SS data set. efine a SS variable, missing values and a SS date values. State the naming conventions for SS data sets and variables. xplain SS syntax rules. Investigate a SS data set using the ONTNTS and PRINT procedures. SS Programs SS program is a sequence of steps that the user submits for execution. Raw Raw ata SS ata Set T steps are typically used to create SS data sets. T Step SS ata Set PRO Step Report PRO steps are typically used to process SS data sets (that is, generate reports and graphs, edit data, and sort data). 3 4 Sample ata Operator File ontaining ata: boxhunter.dat ay of Week

2 Sample SS Program %let ddirect = c:/my data; data one; infile "&ddirect/boxhunter.dat delimiter='09'x; input weekday $ operator $ response; T Step Step oundaries SS steps begin with a T statement, or, PRO statement. SS detects the end of a step when it encounters 7 Options nocenter; proc print data=one; proc means; class operator; var response; PRO Steps 8 a RUN statement (for most steps) a QUIT statement (for some procedures) the beginning of another step (T statement or PRO statement). Step oundaries %let ddirect = c:/my data; data one; infile "&ddirect/boxhunter.dat delimiter='09'x; input weekday $ operator $ response; SS Windowing nvironment Interactive windows enable you to interface with SS. Options nocenter; proc print data=one; 9 proc means; class operator; var response; 10 Submitting a SS Program When you execute a SS program, the output generated by SS is divided into two major parts: SS log contains information about the processing of the SS program, including any warning and error messages. SS output contains reports generated by SS procedures and T steps. SS Log NOT: opyright (c) by SS Institute Inc., ary, N, US. NOT: SS (r) Proprietary Software Release 8.2 (TS2M0) Licensed to ROHSTR INSTITUT OF THNOLOGY, Site NOT: This session is executing on the WIN_PRO platform. NOT: SS initialization used: real time 4.02 seconds cpu time 0.66 seconds 1 %let ddirect = c:/my data; 2 data one; 3 infile "&ddirect/boxhunter.dat delimiter='09'x; 4 input weekday $ operator $ response; 5 NOT: The infile "c:/my data/boxhunter.dat" is: File Name=c:\my data\boxhunter.dat, RFM=V,LRL=256 NOT: 15 records were read from the infile "c:/my data/boxhunter.dat". The minimum record length was 12. The maximum record length was 16. NOT: The data set WORK.ON has 15 observations and 3 variables. NOT: T statement used: real time 0.12 seconds cpu time 0.04 seconds

3 SS Output PRO PRINT The SS System Obs weekday operator response Wednesda Wednesda Wednesda Wednesda Wednesda SS Output - PRO MNS The SS System The MNS Procedure nalysis Variable : response N operator Obs N Mean Std ev Minimum Maximum ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ SS ata Sets SS ata Sets ata ntry escriptor Portion xternal File onversion Process SS ata Set Other Software Files ata Portion SS data sets have a descriptor portion and a data portion. escriptor Portion ata Portion General data set information * data set name * data set label * date/time created * storage information * number of observations Information for each variable * Name * Type * Length * Position * Format * Informat * Label rowsing the escriptor Portion The descriptor portion of a SS data set contains general information about the SS data set (such as data set name and number of observations) variable attributes (name, type, length, position, informat, format, label). The ONTNTS procedure displays the descriptor portion of a SS data set. rowsing the escriptor Portion General form of the ONTNTS procedure: PRO ONTNTS T=SS-data-set; RUN; xample: proc contents data=one; c02s3d1 3

4 SS Variable Values There are two types of variables: character contain any value: letters, numbers, special characters, and blanks. haracter values are stored with a length of 1 to 32,767 bytes. One byte equals one character. The default length for character variables is 8 bytes. SS ata Set and Variable Names SS names can be 32 characters long. can be uppercase, lowercase, or mixed-case. must start with a letter or underscore. Subsequent characters can be letters, underscores, or numeric digits. numeric stored as floating point numbers in 8 bytes of storage by default. ight bytes of floating point storage provide space for 16 or 17 significant digits. You are not restricted to 8 digits Valid SS Names Select the default valid SS names. data5mon 5monthsdata data#5 five months data fivemonthsdata Valid SS Names Select the default valid SS names. data5mon 5monthsdata data#5 five months data fivemonthsdata SS ate Values SS stores date values as numeric values. SS date value is stored as the number of days between January 1, 1960, and a specific date. Missing ata Values value must exist for every variable for each observation. Missing values are valid values. LastName FirstName JobTitle Salary 23 01JN JN JN1961 store display 01/01/ /01/ /01/ TORRS JN Pilot LNGKMM SRH Mechanic SMITH MIHL Mechanic. WGSHL NJ Pilot TORMON JOHN character missing value is displayed as a blank. numeric missing value is displayed as a period. 4

5 rowsing the ata Portion The PRINT procedure displays the data portion of a SS data set. y default, PRO PRINT displays all observations all variables an Obs column on the left side. rowsing the ata Portion General form of the PRINT procedure: PRO PRINT T=SS-data-set; RUN; xample: proc print data=one; SS ata Set Terminology SS documentation and text in the SS windowing environment use the following terms interchangeably: SS ata Set Variable Observation SS Table olumn Row SS Syntax Rules SS statements usually begin with an identifying keyword always end with a semicolon. proc print data=work.staff; class JobTitle; var Salary; 29 SS Syntax Rules SS statements are free-format. One or more blanks or special characters can be used to separate words. They can begin and end in any column. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; 30 SS Syntax Rules SS statements are free-format. One or more blanks or special characters can be used to separate words. They can begin and end in any column. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; 5

6 SS Syntax Rules SS Syntax Rules 31 SS statements are free-format. One or more blanks or special characters can be used to separate words. They can begin and end in any column. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; 32 SS statements are free-format. One or more blanks or special characters can be used to separate words. They can begin and end in any column. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; SS Syntax Rules... SS Syntax Rules SS statements are free-format. One or more blanks or special characters can be used to separate words. They can begin and end in any column. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; 34 SS statements are free-format. They can begin and end in any column. One or more blanks or special characters can be used to separate words. single statement can span multiple lines. Several statements can be on the same line. Unconventional Spacing class JobTitle; var Salary; 35 SS Syntax Rules Good spacing makes the program easier to read. onventional Spacing proc print data=work.staff; class JobTitle; var Salary; 36 SS omments Type /* to begin a comment. Type your comment text. Type */ to end the comment. /* reate work.staff data set */ /* Produce listing report of work.staff */ proc print data=work.staff; 6

7 ommon Syntax rrors Syntax errors include misspelled keywords (PRO spelled as PRO) missing or invalid punctuation (missing ;) invalid options (misspelled, or wrong options for a given procedure) Recall a Submitted Program Program statements accumulate in a recall buffer each time you issue a SUMIT (F3) command. Issue the RLL (F4) command once to recall the most recently submitted program. Issue the KYS (F9) command to tell you what functions have been assigned to which key combinations Save Your Program Use the FIL command with the appropriate file naming convention for your operating environment. Windows: FIL 'c:\workshop\winsas\prog1\myprog.sas' You can also use the FIL/SV or FIL/SV S menu options in the SS display manager. Summary The two main types of steps in SS programs are T steps and PRO steps. T steps are primarily used for data management tasks, while PRO steps contain various procedures. Some special statements, like the OPTIONS statement, may exist outside of the PRO and T steps. The end of a PRO or T step is detected when a RUN or QUIT statement is encountered, or another PRO or T statement is encountered. SS programs are generally executed from a SS Windowing environment. When SS programs are executed, a SS LOG and a SS LISTING is created Summary SS variables are either numeric, or character. missing value in SS is a period if the variable is numeric, a blank if the variable is character. ates in SS are numeric variables, but require special formatting to be displayed properly. SS statements end with a semicolon. Use comments liberally to document SS programs. Introduction to Minitab Programs 41 7

8 Objectives State the components of a Minitab program. escribe how Minitab programs are executed in the windowing environment. efine the components of a Minitab worksheet. efine a Minitab variable. Identify a missing value and a Minitab date value. State the naming conventions for Minitab variables. xplain Minitab syntax rules. Investigate a Minitab Project using the Project Manager Window. Minitab Programs Minitab program is a sequence of command that the user types into the command window, or are entered into the command window via the pull-down menus. Raw Raw ata MNIP and L menu commands are used to create and modify data. MNIP and and L Minitab Worksheet STT and and GRPH Report Minitab Worksheet STT and GRPH menu commands are used to create numerical reports and graphical displays Sample ata Operator File ontaining ata: boxhunter.dat ay of Week Minitab Program Read ":\My ata\boxhunter.dat" c1-c3; Tab; NoNames; lpha 1 2; ecimal ".". Name 1='workday'. Name 2='operator'. Name 3='response'. Print 1-3. escribe 3; y 2. * See also: FIL/OPN WORKSHT Minitab Windowing nvironment Interactive windows enable you to interface with Minitab

9 xecuting a Minitab Program You may execute a Minitab program in three different ways: 1. use the XUT command in the SSSION window (stored as filename.mtb), 2. type the commands interactively in the SSSION window, or, 3. use the pull-down menus to generate the commands. Minitab Session Results MT > xecute ":\ocuments and Settings\smleqa.MIN\My ocuments\ourses\742\ (fall)\class1sample1.mtb" 1. xecuting from file: :\ocuments and Settings\smleqa.MIN\My ocuments\ourses\742\ (fall)\class1sample1.mtb ntering data from file: :\My ata\boxhunter.dat 15 rows read. ata isplay Row workday operator response escriptive Statistics: response by operator Variable operator N Mean Median TrMean Stev response Variable operator S Mean Minimum Maximum Q1 Q3 response PRINT Output Row workday operator response SRI Output escriptive Statistics: response by operator Variable operator N Mean Median TrMean Stev response Variable operator S Mean Minimum Maximum Q1 Q3 response Minitab ata Sets Minitab Text ata Rules for text data include: olumns onstants Worksheet 1 Text data in a column may be up to 80 characters long. 2 You may use any characters (letters, numbers, punctuation symbols, blanks). 3 No column can contain both text and numeric data: Minitab treats numbers appearing in an text column (as in a street address) as text characters. Matrices

10 Minitab Numeric ata Minitab stores and computes numbers in double precision, which means that numbers can have up to 15 or 16 digits (depending on the number) without round-off error. Minitab Variable Names Minitab Names cannot be longer than 31 characters begin or end with a blank include the symbol or # start with or consist entirely of the symbol * be repeated: you cannot use the same name for two variables (columns, stored constants or matrices) in the same worksheet Note: names are assigned using: NM 1 = varname Valid Minitab Names Select the default valid Minitab names. data5mon 5monthsdata data#5 five months data fivemonthsdata Minitab ate Values Minitab stores date values as numeric values. Minitab date value is stored as the number of days between Midnight, ecember 30, 1899, and a specific date store display 12/30/ /30/ /30/ Missing ata Values value must exist for every variable for each observation. Missing values are valid values. LastName FirstName JobTitle Salary TORRS JN Pilot LNGKMM SRH Mechanic SMITH MIHL Mechanic * WGSHL NJ Pilot TORMON JOHN rowsing the ata Portion The PRINT command displays the data portion of a Minitab worksheet. y default, PRINT displays all observations only the variables listed vertically, with a Row column on the left side (if more than one column is printed) horizontally (if only one column is printed) 59 character missing value is displayed as a blank. numeric missing value is displayed as a asterisk

11 Minitab ata Set Terminology Minitab Syntax Rules Minitab documentation uses the following terms interchangeably: Minitab statements usually begin with an identifying keyword 61 ata Variable Observation Worksheet olumn Row 62 end with a period (a carriage return implies a period). Read ":\My ata\boxhunter.dat" c1-c3; Tab; NoNames; lpha 1 2; ecimal ".". Name 1='workday'. Name 2='operator'. Name 3='response'. Print 1-3. escribe 3; y 2. Minitab Syntax Rules Minitab Syntax Rules One or more blanks can separate words. ommands can begin and end in any column. n ampersand (&) is used to signal that a statement is to continue onto the next line Only one statement can be on the same line. Read ":\My ata\boxhunter.dat" c1-c3; Tab; NoNames; lpha 1 2; ecimal ".". Name 1='workday 2='operator & 3='response'. Print 1-3. escribe 3; y 2. Good spacing makes the program easier to read. Text that follows a # is considered a comment. Use comments to make the program more readable. Read ":\My ata\boxhunter.dat" c1-c3; Tab; # indicates that the file is tab delimited NoNames; # names are not the first line of file lpha 1 2; # first two columns are text variables ecimal ".". Name 1='workday 2='operator & # continuation 3='response'. Print 1-3. # let s do some summary statistics escribe 3; y ommon Syntax rrors Syntax errors include misspelled keywords missing or invalid punctuation invalid options. Save Your Project or Worksheet Use the FIL/ SV PROJT command to save everything! Use the FIL/ SV URRNT WORKSHT command to save individual worksheets! Note: the worksheet can be saved in formats other than the Minitab format! If the SSSION window is in front, you can also save that window separately, or cut and paste into other applications parts of the session, or graph, windows

12 Minitab Project Manager Minitab Project Manager Session an indexed session window History a record of all Minitab commands executed Graphs the graphs that have been created Report Pad a place to paste results and write notes Worksheet olumns 1, 2, etc. onstants K1, K2, etc. Matrices M1, M2, etc. Note: the INFO command summarizes information about the current worksheet Summary Minitab variables are either numeric, or character, or dates. missing value in Minitab is an asterisk if the variable is numeric, a blank if the variable is character. Minitab statements end with a period (.). Minitab statements end at the end of the line, unless a continuation character (&) is used. semicolon (;) is used in Minitab to indicate that a subcommand is to follow on the next line. Only one Minitab command may occupy each line. Use comments liberally to document Minitab programs. Introduction to xcel Spreadsheets 69 Objectives State the components of a xcel Workbook. escribe how xcel can be used to get statistical summaries. efine the components of a xcel Workbooks. escribe type of data allowed in cells. xcel Workbook ells Worksheets Workbook

13 Sample ata ay of Week Operator xcel Worksheet Sequence of Steps: 1.Use FIL/OPN to get data in 2.Use INSRT/ROWS to make room for variable names. 3.Type variable names into appropriate cells. 4.Highlight all three columns. 5.Use T/PivotTable to create table of averages, repeat for other statistics xcel ata Worksheet Weekday Operator Response xcel Workbooks Workbooks contain worksheets Worksheets contain ells ells contain data, or functions, or references to other cells xcel Text ata and Variable Names No obvious rules for enter text data, or for that matter, variable names (since they are usually just text cells) xcel Numeric ata 15-digit limit Regardless of the number of digits displayed, xcel stores numbers with up to 15 digits of precision. If a number contains more than 15 significant digits, xcel converts the extra digits to zeros (0). Note: although xcel stores numbers in about the same precision as SS and Minitab, it has some other numerical deficiencies at will be demonstrated in the homework assignment. 78 xcel ate Values xcel stores date values as numeric values. n xcel date value is stored as the number of days between Midnight, ecember 30, 1899, and a specific date store display 12/30/ /30/ /30/

14 Save Your Workbook or Worksheet Use the FIL/ SV to save the current workbook. Note: the individual worksheets can be saved in formats other than the xcel workbook format! Summary xcel organizes cells into worksheets, and worksheets into workbooks. ata and functions are entered into cells. xcel cells may contain numeric, or character values, functions, or a number of other constructs. There is no explicit missing value in xcel. ates in xcel are numeric variables, but may require special formatting to be displayed properly. omments can be inserted into cells to document the worksheet xample ata Suppose you are measuring the one dimension of a number of manufactured parts which were all designed to be identically 13 cm. Of course, with manufacturing variability, the parts are not exactly 13 cm. Here are the results from a sample of 16 parts. MO: SS, Minitab, and xcel ased on this sample, what would you estimate the mean and standard deviation of the distribution of parts to be? xpress your answer in millimeters. ata are saved in length.txt 82 Getting In and Getting Out Microsoft xcel ouble-click on Icon File/xit Minitab ouble-click on Icon File/xit SS ouble-click on Icon File/xit Interfaces xecuting ommands Microsoft xcel live Worksheets are edited directly Minitab - semi-live Worksheets are edited via commands executed in the session window SS not as live atasets is edited via programs submitted from the program editor window

15 ntering Simple ata Microsoft xcel File/New/Workbook (contains Worksheets) Type data in columns File/Save s/ (in any folder) Minitab File/New/Minitab Worksheet Type data in columns File/Save urrent Worksheet s/ (in any folder) SS Use the sample program as a template, modify it to work with the length data type it into the editor Submit, then look at the Output Window (Re) isplaying ata Microsoft xcel File/Print Minitab ommand: PRINT 1. (current worksheet, first column, default formats) SS Procedure: PRO PRINT; (current dataset, all variables, default formats) reating a New Variable Microsoft xcel =1+1 assignment statement typed directly in each cell Minitab LT 2=1+1 assignment statement in session window for each new column SS newvar = oldvar + 1; added to the SS data step and submitted via the program editor window SUMMRY SV your data! SV your programs! Use the HLP commands! Use non-generic variable names and labels! Use comments to document programs! Use indentation and capitalization to make programs easy to read! e aware of display formatting and data storage issues!