LOGISTIC Function

Returns the logistic transformation of the argument.

Category:	Mathematical

Table of Contents

Syntax

LOGISTIC(argument)

Required Argument

argument

is a numeric variable, constant, or expression that specifies the value of a numeric random variable. When argument is a missing or null value, the LOGISTIC function returns a missing or null value.

Details

The LOGISTIC function returns the logistic transformation of an argument. It is typically used to convert a log odds value to a value on the probability scale. The function is mathematically expressed by the following equation:

italic logistic equals multiline equation line 1 StartFraction e Superscript x Baseline Over 1 plus e Superscript x Baseline EndFraction. Click image for alternative formats.

If the argument contains a missing value, then the LOGISTIC function returns a missing or null value.

Example

The following program illustrates the LOGISTIC function:

Note: In this example, DS2 statements are sent to SAS using PROC DS2.

proc ds2;
data test (overwrite=yes); 
   dcl double a b;
   method run();
      a=logistic(.5);
      b=logistic(7.3);
      put  'a= ' a;
      put 'b=' b;
   end;
enddata;
run;
quit;

proc ds2;
data test (overwrite=yes); 
   dcl double a b;
   method run();
      a=logistic(.5);
      b=logistic(7.3);
      put  'a= ' a;
      put 'b=' b;
   end;
enddata;
run;
quit;

SAS writes the following output to the log:

a=  0.62245933120185
b= 0.99932491726936

Last updated: September 2, 2026