Command: UnitStep

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Name:
 UnitStep - The unit step function (aka Heavyside function)
Synopsis:
              x  UnitStep -> 0   ;if  x <  0
                          -> 1   ;if  x >= 0
     [x1 x2 ...] UnitStep -> 0   ;if xi <  0 for any xi in [x]
                          -> 1   ;if xi >= 0 for all xi in [x]
Description:
     "x UnitStep" represents the unit step function,
     equal to 0 for x<0 and 1 for x>=0.

     "[x1 x2 ...] UnitStep" represents the multidimensional unit step
     function which is 1 only if none of the xi are negative.

     Alternatives: Function UnitStep_i for integers, UnitStep_d for
     doubles, UnitStep_ia for integer arrays, UnitStep_da for double
     arrays (all undocumented) -> behavior and synopsis are the same,
     except that no warnings or error messages are thrown.
Diagnostics:
     When called on an empty array, /ArgumentType is raised.

     When first element of the array is not of type integer or double,
     /ArgumentType is raised.

     Will break if called on an array containing non-numerical values.
Author:
 Ruediger Kupper
FirstVersion:
 13.3.2003
Remarks:
     This is the SLI version of the Mathematica function "UnitStep".
     Documentation taken from the Mathematica Book.

     Implementation of the type variants can be found in file
     synod2/sli/slimath.cc.
SeeAlso:Sign abs
References:
     The Mathematica Book
Source:
 /home/abuild/rpmbuild/BUILD/nest-2.4.1/lib/sli/mathematica.sli

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