LN and NOLOG Subcommands (PPLOT command)

LN transforms the data by using the natural logarithm (base e) to remove varying amplitude. NOLOG indicates that the data should not be log transformed. NOLOG is the default.

  • There are no additional specifications on LN or NOLOG.
  • Only the last LN or NOLOG subcommand on a PPLOT command is executed.
  • If a natural log transformation is requested, cases with values that are less than or equal to 0 will be set to system-missing, because nonpositive values cannot be log-transformed.
  • NOLOG is generally used with an APPLY subcommand to turn off a previous LN specification.

Example

PPLOT VARIABLES = TICKETS
  /FRACTION=TUKEY
  /DIFF=1
  /LN.
PPLOT VARIABLES = EARNINGS
  /APPLY
  /NOLOG.
  • The first command requests a natural log transformation of variable TICKETS before plotting.
  • The second command applies the previous PPLOT specifications to variable EARNINGS. However, EARNINGS is not log-transformed before plotting.