SUPPORT / SAMPLES & SAS NOTES
 

Support

Problem Note 16089: Transform Variables node may incorrectly assign missing values when taking the log

DetailsHotfixAboutRate It
Taking the logarithm is one of the transformations that the Transform
Variables node provides.  If the minimum value of the variable being
transformed (X) is less than or equal to 0 in the metadata sample, the
node adds a constant (C) to every value to make the minimum 1 before
logging.

  Y = log(X+C)

Since the minimum of the variable in the metadata sample might not be as
small as the minimum of the variable in the full data set, the node
assigns a non-missing transformed value only if X is greater than 0.

   If X > 0 then Y=log(X+C);
      else Y = .;

This is not correct, and as a result, observations might be assigned a
missing value by mistake.

Instead, the node should assign a non-missing transformed value only if
(X+C) is greater than 0.

  If (X+C) > 0 then Y=log(X+C)
      else Y=.;

There are no error or warning messages to indicate there is a problem.

The only way to know that the values are incorrect is to compare the
minimum value in the full data set to the minimum value in the metadata
sample.  If they are not the same, then the problem will occur.

A fix for SAS Enterprise Miner Server 4.3 for this issue is
available at:

http://ftp.sas.com/techsup/download/hotfix/dmine43.html

A fix for SAS Enterprise Miner Server 4.3 for National Language
Support (Japanese Translations) for this issue is available at:

http://ftp.sas.com/techsup/download/hotfix/nls_d9_ja.html


Operating System and Release Information

Product FamilyProductSystemProduct ReleaseSAS Release
ReportedFixed*ReportedFixed*
SAS SystemSAS Enterprise MinerMicrosoft Windows NT Workstation4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows Server 2003 Standard Edition4.35.19.1 TS1M39.1 TS1M0
Microsoft® Windows® for 64-Bit Itanium-based Systems4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows Server 2003 Enterprise Edition4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows Server 2003 Datacenter Edition4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows 2000 Professional4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows 2000 Server4.35.19.1 TS1M39.1 TS1M0
Solaris4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows 2000 Advanced Server4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows 2000 Datacenter Server4.35.19.1 TS1M39.1 TS1M0
z/OS4.35.19.1 TS1M39.1 TS1M0
64-bit Enabled Solaris4.35.19.1 TS1M39.1 TS1M0
Microsoft Windows XP Professional4.35.19.1 TS1M39.1 TS1M0
Linux4.35.19.1 TS1M39.1 TS1M0
HP-UX4.35.19.1 TS1M39.1 TS1M0
HP-UX IPF4.35.19.1 TS1M39.1 TS1M0
64-bit Enabled HP-UX4.35.19.1 TS1M39.1 TS1M0
64-bit Enabled AIX4.35.19.1 TS1M39.1 TS1M0
OpenVMS Alpha4.35.19.1 TS1M39.1 TS1M0
Tru64 UNIX4.35.19.1 TS1M39.1 TS1M0
AIX4.35.19.1 TS1M39.1 TS1M0
* For software releases that are not yet generally available, the Fixed Release is the software release in which the problem is planned to be fixed.