24764 - Stratified random sample with replacement, unequal allocation

Sample 24764: Stratified random sample with replacement, unequal allocation

/* Create sample data base of student grade point averages from East High */
/* School, Grades 9 through 12, 100 or more students per grade.  Sampling */
/* will be done with replacement, so an individual student's score may be */
/* sampled more than once.                                                */
 
data EastHigh;
  format GPA 3.1;
  do Grade=9 to 12;
    do StudentID=1 to 100+int(201*ranuni(432098));
      GPA=2.0 + (2.1*ranuni(34280));
      output;
    end;
  end;
run;
 
/* Method 1: Use PROC SURVEYSELECT if you have SAS/STAT Version 7 or higher   */
/*                                                                            */
/* Sample 4 students from Grade 9 , 6 from Grade 10, and 10 from both Grades  */
/* 11 and 12.  N= is the number of observations to select from each group.    */
/* Use METHOD=URS to request unrestricted random sampling, which is selection */
/* with equal probability and with replacement.  The statement STRATA defines */
/* the variable that is used for grouping.  OUT= names the SAS data set that  */
/* will be created by the procedure.                                          */
 
proc surveyselect data=EastHigh method=urs n=(4, 6, 10, 10) out=sample;
  strata Grade;
run;
 
title 'Surveyselect Method';
proc print data=sample;
run;
 
 
 
/* Method 2: Use Base SAS if you do not have SAS/STAT Version 7 or higher       */
/*                                                                              */
/* Sample 4 students from Grade 9, 6 from Grade 10, and 10 from both Grades     */
/* 11 and 12. Use RANUNI to  generate the observation numbers to be sampled.    */
/* Note that the data set is sorted by Grade.  In a following DATA step, create */
/* a counter that increments with each iteration of the step and resets to 0    */
/* when the BY-Group changes.  For each BY-Group specify the maximum number     */
/* of observations to sample.  Output until the counter matches the maximum     */
/* number to output per BY-Group.                                               */
 
/* Determine the starting observation and ending observation for each grade, */
/* or BY-Group.  Use this information to determine the random observations   */
/* to sample from each BY-Group.                                             */
 
data bygroup_range;
  keep grade start stop;
  set easthigh;
  by grade;
  retain start;
  if first.grade then start=_N_;
  else if last.grade then do;
    stop=_N_;
    output;
 end;
run;
 
proc print data=bygroup_range;
  title 'Using Base SAS';
run;
 

/* RANUNI generates a random number between 0 and 1.  To randomly sample from */
/* within a specified numeric range that starts at one, multiply the RANUNI   */
/* result by the maximum of the range.  For numeric ranges that do not start  */
/* with one,  multiply the RANUNI result by the range of data values you want */
/* to capture (maximum - minimum) plus one and add the first integer below    */
/* the minimum to the product.                                                */
 
data grab;
  do i = 1 to 4;
    grade = 9;
    obs2sample = ceil(ranuni(1234)*292);
    output;
  end;
  do i = 1 to 6;
    grade = 10;
    obs2sample = ceil(ranuni(4321)*120) + 292;
    output;
  end;
  do i = 1 to 10;
    grade = 11;
    obs2sample = ceil(ranuni(6789)*166) + 412;
    output;
  end;
  do i = 1 to 10;
    grade = 12;
    obs2sample = ceil(ranuni(9876)*223) + 578;
    output;
  end;
run;
 
/* GRAB contains the value for the observation number to sample from EASTHIGH */

data final;
  set grab(keep= obs2sample);
  set easthigh point=obs2sample;
  output;
run;
 
proc print data=final;
  title 'Using DATA step';
run;

These sample files and code examples are provided by SAS Institute Inc. "as is" without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and fitness for a particular purpose. Recipients acknowledge and agree that SAS Institute shall not be liable for any damages whatsoever arising out of their use of this material. In addition, SAS Institute will provide no support for the materials contained herein.

Surveyselect Method

                       Student    Number    Expected    Sampling
Obs    Grade    GPA       ID       Hits       Hits       Weight

  1       9     2.5      139         1      0.013699      73.0
  2       9     2.3      216         1      0.013699      73.0
  3       9     4.1      225         1      0.013699      73.0
  4       9     2.5      252         1      0.013699      73.0
  5      10     3.0        5         1      0.050000      20.0
  6      10     2.3       30         1      0.050000      20.0
  7      10     3.0       68         1      0.050000      20.0
  8      10     2.3       73         1      0.050000      20.0
  9      10     3.0       79         1      0.050000      20.0
 10      10     3.4       93         1      0.050000      20.0
 11      11     3.4       19         1      0.060241      16.6
 12      11     2.1       39         1      0.060241      16.6
 13      11     2.3       66         1      0.060241      16.6
 14      11     2.1       67         1      0.060241      16.6
 15      11     2.6       78         1      0.060241      16.6
 16      11     4.0       86         1      0.060241      16.6
 17      11     3.2      100         1      0.060241      16.6
 18      11     3.4      122         1      0.060241      16.6
 19      11     3.7      138         1      0.060241      16.6
 20      11     3.6      156         1      0.060241      16.6
 21      12     2.2       42         1      0.044843      22.3
 22      12     3.6       55         1      0.044843      22.3
 23      12     4.0       57         1      0.044843      22.3
 24      12     2.5       66         1      0.044843      22.3
 25      12     2.7      123         1      0.044843      22.3
 26      12     2.7      150         1      0.044843      22.3
 27      12     2.1      158         1      0.044843      22.3
 28      12     3.3      183         1      0.044843      22.3
 29      12     4.1      204         1      0.044843      22.3
 30      12     3.5      214         1      0.044843      22.3



Using Base SAS

Obs    Grade    start    stop

 1        9        1      292
 2       10      293      412
 3       11      413      578
 4       12      579      801



Using DATA step

                       Student
Obs    GPA    Grade       ID

  1    3.9       9        72
  2    2.8       9        27
  3    2.1       9       112
  4    3.5       9        29
  5    2.4      10        31
  6    2.6      10        11
  7    3.0      10         5
  8    3.8      10        13
  9    3.1      10        54
 10    2.9      10        18
 11    3.8      11         7
 12    3.7      11        76
 13    3.5      11        15
 14    2.2      11       151
 15    2.9      11       161
 16    2.2      11       123
 17    2.1      11        67
 18    2.5      11        62
 19    2.6      11        55
 20    2.4      11        85
 21    3.8      12        64
 22    3.3      12        79
 23    2.2      12        58
 24    2.9      12        98
 25    2.9      12        28
 26    3.9      12       160
 27    3.6      12         1
 28    2.1      12       114
 29    2.8      12       202
 30    2.4      12        53

Select a random sample of data where the number of observations chosen from each group are of different sizes, with replacement.

Type:	Sample
Topic:	Analytics ==> Survey Sampling and Analysis SAS Reference ==> DATA Step SAS Reference ==> Procedures ==> SURVEYSELECT

Date Modified:	2016-01-11 16:09:15
Date Created:	2004-09-30 14:09:11

Operating System and Release Information

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Product Family	Product	Host	Starting	Ending
SAS System	Base SAS	Aster Data nCluster on Linux x64
		DB2 Universal Database on AIX
		DB2 Universal Database on Linux x64
		Greenplum on Linux x64
		Netezza TwinFin 32bit blade
		Netezza TwinFin 32-bit SMP Hosts
		Netezza TwinFin 64-bit S-Blades
		Netezza TwinFin 64-bit SMP Hosts
		Teradata on Linux
		z/OS
		z/OS 64-bit
		OpenVMS VAX
		Microsoft® Windows® for 64-Bit Itanium-based Systems
		Microsoft Windows Server 2003 Datacenter 64-bit Edition
		Microsoft Windows Server 2003 Enterprise 64-bit Edition
		Microsoft Windows XP 64-bit Edition
		Microsoft® Windows® for x64
		OS/2
		Microsoft Windows 8 Enterprise 32-bit
		Microsoft Windows 8 Enterprise x64
		Microsoft Windows 8 Pro 32-bit
		Microsoft Windows 8 Pro x64
		Microsoft Windows 8.1 Enterprise 32-bit
		Microsoft Windows 8.1 Enterprise x64
		Microsoft Windows 8.1 Pro
		Microsoft Windows 8.1 Pro 32-bit
		Microsoft Windows 10
		Microsoft Windows 95/98
		Microsoft Windows 2000 Advanced Server
		Microsoft Windows 2000 Datacenter Server
		Microsoft Windows 2000 Server
		Microsoft Windows 2000 Professional
		Microsoft Windows NT Workstation
		Microsoft Windows Server 2003 Datacenter Edition
		Microsoft Windows Server 2003 Enterprise Edition
		Microsoft Windows Server 2003 Standard Edition
		Microsoft Windows Server 2003 for x64
		Microsoft Windows Server 2008
		Microsoft Windows Server 2008 R2
		Microsoft Windows Server 2008 for x64
		Microsoft Windows Server 2012 Datacenter
		Microsoft Windows Server 2012 R2 Datacenter
		Microsoft Windows Server 2012 R2 Std
		Microsoft Windows Server 2012 Std
		Microsoft Windows XP Professional
		Windows 7 Enterprise 32 bit
		Windows 7 Enterprise x64
		Windows 7 Home Premium 32 bit
		Windows 7 Home Premium x64
		Windows 7 Professional 32 bit
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		Windows 7 Ultimate 32 bit
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		Windows Millennium Edition (Me)
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		HP-UX
		HP-UX IPF
		IRIX
Linux
Linux for x64
Linux on Itanium
OpenVMS Alpha
OpenVMS on HP Integrity
Solaris
Solaris for x64
Tru64 UNIX
SAS System	SAS/STAT	z/OS
		z/OS 64-bit
		OpenVMS VAX
		Microsoft® Windows® for 64-Bit Itanium-based Systems
		Microsoft Windows Server 2003 Datacenter 64-bit Edition
		Microsoft Windows Server 2003 Enterprise 64-bit Edition
		Microsoft Windows XP 64-bit Edition
		Microsoft® Windows® for x64
		OS/2
		Microsoft Windows 8 Enterprise 32-bit
		Microsoft Windows 8 Enterprise x64
		Microsoft Windows 8 Pro 32-bit
		Microsoft Windows 8 Pro x64
		Microsoft Windows 8.1 Enterprise 32-bit
		Microsoft Windows 8.1 Enterprise x64
		Microsoft Windows 8.1 Pro
		Microsoft Windows 8.1 Pro 32-bit
		Microsoft Windows 10
		Microsoft Windows 95/98
		Microsoft Windows 2000 Advanced Server
		Microsoft Windows 2000 Datacenter Server
		Microsoft Windows 2000 Server
		Microsoft Windows 2000 Professional
		Microsoft Windows NT Workstation
		Microsoft Windows Server 2003 Datacenter Edition
		Microsoft Windows Server 2003 Enterprise Edition
		Microsoft Windows Server 2003 Standard Edition
		Microsoft Windows Server 2003 for x64
		Microsoft Windows Server 2008
		Microsoft Windows Server 2008 R2
		Microsoft Windows Server 2008 for x64
		Microsoft Windows Server 2012 Datacenter
		Microsoft Windows Server 2012 R2 Datacenter
		Microsoft Windows Server 2012 R2 Std
		Microsoft Windows Server 2012 Std
		Microsoft Windows XP Professional
		Windows 7 Enterprise 32 bit
		Windows 7 Enterprise x64
		Windows 7 Home Premium 32 bit
		Windows 7 Home Premium x64
		Windows 7 Professional 32 bit
		Windows 7 Professional x64
		Windows 7 Ultimate 32 bit
		Windows 7 Ultimate x64
		Windows Millennium Edition (Me)
		Windows Vista
		Windows Vista for x64
		64-bit Enabled AIX
		64-bit Enabled HP-UX
		64-bit Enabled Solaris
		ABI+ for Intel Architecture
		AIX
		HP-UX
		HP-UX IPF
		IRIX
		Linux
		Linux for x64
		Linux on Itanium
		OpenVMS Alpha
		OpenVMS on HP Integrity
		Solaris
		Solaris for x64
		Tru64 UNIX

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Sample 24764: Stratified random sample with replacement, unequal allocation

Operating System and Release Information