SAS/ACCESS Software for PC File Formats: Reference

Calculating Statistics

You can also use SAS statistical procedures on PC files data. This section shows examples using the FREQ, MEANS, and RANK procedures.

Using the FREQ Procedure

Suppose you want to find the percentages of your invoices that went to each country so that you can decide where to increase your overseas marketing. The following example uses the view descriptor VLIB.INV to calculate the percentage of invoices for each country that appears in the INVOICE.DBF file.

proc access dbms=dbf;
   /* create access descriptor   */
   create adlib.invoice.access;
      path="c:\sasdemo\invoice.dbf";
   assign;
   rename invoicenum = invnum
          amtbilled = amtbilld ;
   format paidon      date9.
          invoicenum  5.0
          billedby    6.0;
   assign=yes;

   create vlib.inv.view;
   /* create vlib.inv view      */
   select invoicenum amtbilled
          country billedby paidon;
   list all;
run;

proc freq data=vlib.inv;
   /* example             */
   tables country;
   title 'Data Described by VLIB.INV';
run;

Frequency Table for Variable COUNTRY Described by View Descriptor VLIB.INV shows the one-way frequency table that this example generates.

Frequency Table for Variable COUNTRY Described by View Descriptor VLIB.INV

Data Described by VLIB.INV 6 COUNTRY Cumulative Cumulative COUNTRY Frequency Percent Frequency Percent -------------------------------------------------------------- Argentina 2 11.76 2 11.76 Australia 1 5.88 3 17.65 Brazil 4 23.53 7 41.18 USA 10 58.82 17 100.00

For more information on the FREQ procedure, see SAS Language and Procedures: Usage and SAS Procedures Guide.

Using the MEANS Procedure

In your analysis of recent orders, suppose you also want to calculate some statistics for each U.S. customer. From the ORDERS.XLS file, the view descriptor VLIB.USAORDR selects a subset of observations that have a SHIPTO value beginning with a 1, indicating a U.S. customer.

Using the OUT= option in the SORT procedure, the data from the DBF file are extracted, placed in a SAS data file, and then sorted.

The following example generates the means and sums of the length of material ordered (in yards) and the fabric charges (in dollars) for each U.S. customer. Also included are the number of observations (N) and the number of missing values (NMISS). The MAXDEC= option specifies the number of decimal places (0-8) for PROC MEANS to use in printing the results.

proc access dbms=xls;
    create adlib.order.access;       
    /* create access descriptor    */
    path="c:\sasdemo\orders.xls";
    worksheet=shee1;
    getnames=yes;
    skiprows=2;
    scantype=5;
    mixed=yes;
    assign=yes;
    rename dateorderd = dateord
           processdby = procesby;
    format dateorderd  date9.
           shipped     date9.
           ordernum    5.0
           length      4.0
           stocknum    4.0
           takenby     6.0
           processdby  6.0
           fabcharges  12.2;
    list all;

    create vlib.usaordr.view;        
    /* create vlib.usaordr view  */
    select ordernum stocknum length
           fabcharges shipto;
    subset where shipto like '1%';
run;

proc sort data=vlib.usaordr out=work.usaorder;
    by shipto;
run;

proc means data=work.usaordr mean    
     /* example             */
     sum n nmiss maxdec=0;
   by shipto;
   var length fabcharg;
title 'Data Described by VLIB.USAORDR';
run;

Statistics on Fabric Length and Charges for Each U.S. Customer shows the output for this example.

Statistics on Fabric Length and Charges for Each U.S. Customer

Data Described by VLIB.USAORDR 7 -------------------------------- SHIPTO=14324742 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 1095 4380 4 0 FABCHARG FABCHARGES 1934460 3868920 2 2 ----------------------------------------------------------- -------------------------------- SHIPTO=14898029 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 2500 5000 2 0 FABCHARG FABCHARGES 1400825 2801650 2 0 ----------------------------------------------------------- -------------------------------- SHIPTO=15432147 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 725 2900 4 0 FABCHARG FABCHARGES 252149 504297 2 2 ----------------------------------------------------------- -------------------------------- SHIPTO=18543489 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 303 1820 6 0 FABCHARG FABCHARGES 11063836 44255344 4 2 ----------------------------------------------------------- -------------------------------- SHIPTO=19783482 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 450 1800 4 0 FABCHARG FABCHARGES 252149 1008594 4 0 ----------------------------------------------------------- -------------------------------- SHIPTO=19876078 ------------------------------- Variable Label Mean Sum N Nmiss ----------------------------------------------------------- LENGTH LENGTH 690 1380 2 0 FABCHARG FABCHARGES . . 0 2 -----------------------------------------------------------

For more information on the MEANS procedure, see SAS Procedures Guide.

Using the RANK Procedure

You can also use more advanced statistical procedures on PC files data. The following example uses the RANK procedure to calculate the order of birthdays for a set of employees who are listed in the EMPLOYEES.DBF file. The OUT= option creates a SAS data file, DLIB.RANKEXAM, from the view descriptor VLIB.EMPS so that the data in the SAS file can be sorted by the SORT procedure. The RANKS statement assigns the name DATERANK to the new variable (in the SAS data file) that is created by the procedure. The PRINT procedure then prints the data that are described by DLIB.RANKEXAM. You can also use the PRINT procedure to print all or some of the PC file data values described by view descriptors.

proc access dbms=dbf;
   create adlib.employ.access;             
   /* create access descriptor  */
   path="c:\sasdemo\employees";
   drop salary;
   list all;

   create vlib.emps.view;                   
   /* create vlib.emps view     */
   select empid jobcode birthdate 
      lastname jobcode;
   format birthdate date9.
          empid     6.0;
   subset where jobcode=602;
run;

proc rank data=vlib.emps out=dlib.rankexam;   
   /* example          */
   var birthdat;
   ranks daterank;
run;

proc sort data=dlib.rankexam;
   by lastname;
run;

proc print data=dlib.rankexam(drop=jobcode);
   title 'Order of Dept 602 Employee Birthdays';
run;

Data stored in the DBF file must be extracted and placed in a SAS data set before they can be sorted with a SAS procedure. (This restriction also applies to data from other PC files.) The DROP= data set option is used in the PROC PRINT statement because the JOBCODE variable is not needed in the output. The JOBCODE variable is required in the SELECT statement so it can be used in the WHERE statement. The JOBCODE variable is then included in the view descriptor, even though it is not needed in the output. Ranking of Employee Birthdays shows the result of this example.

Ranking of Employee Birthdays

Order of Dept 602 Employee Birthdays OBS EMPID BIRTHDAT LASTNAME DATERANK 1 456910 24SEP1953 ARDIS 5 2 237642 13MAR1954 BATTERSBY 6 3 239185 28AUG1959 DOS REMEDIOS 7 4 321783 03JUN1935 GONZALES 2 5 120591 12FEB1946 HAMMERSTEIN 4 6 135673 21MAR1961 HEMESLY 8 7 456921 12MAY1962 KRAUSE 9 8 457232 15OCT1963 LOVELL 11 9 423286 31OCT1964 MIFUNE 12 10 216382 24JUL1963 PURINTON 10 11 234967 21DEC1967 SMITH 13 12 212916 29MAY1928 WACHBERGER 1 13 119012 05JAN1946 WOLF-PROVENZA 3

When you use the PRINT procedure, you may want to take advantage of the SAS data set option OBS=, which enables you to limit the number of observations to be processed. This option is especially useful when the view descriptor describes a large amount of data, the SAS data file is large, or when you just want to see an example of the output. You cannot use OBS= if the view descriptor contains a WHERE clause in the SUBSET statement.

For more information on RANK, on other advanced statistical procedures, and for the PRINT procedure, see SAS Procedures Guide. For more information on the OBS= and FIRSTOBS= options, see SAS Language Reference: Dictionary.

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