sqrt(3M)

NAME
     SQRT, DSQRT, CSQRT, CDSQRT - Computes square root

SYNOPSIS
     UNICOS and UNICOS/mk systems:

     SQRT ([X=]x)
     DSQRT ([X=]x)
     CSQRT ([X=]x)

     UNICOS and IRIX systems:

     CDSQRT ([X=]x)

IMPLEMENTATION
     UNICOS, UNICOS/mk, and IRIX systems

STANDARDS
     Fortran 90
     CDSQRT is a compiler extension to Fortran 90.

DESCRIPTION
     SQRT is the generic function name.  These functions are elemental
     functions for the CF90 compiler.

     A vector version of this intrinsic exists on UNICOS and UNICOS/mk
     systems.  On UNICOS/mk systems, the vector version of this intrinsic
     is used when -h vector3 (C compiler) or -O vector3 or -O3 (Fortran
     compiler) has been specified on the compiler command line.

     The entry point CDSQRT is provided for support in other languages.  It
     is not recognized as an intrinsic function; therefore, you must use
     the CDIR$ VFUNCTION directive to allow vectorization.

     CDSQRT is called implicitly by the Fortran 90 compiler as a result of
     a generic SQRT call with a complex double-precision argument.
                                   1/2
     These functions evaluate y = x   .

   CAL Register Usage (Cray Research Systems Only)
     Scalar SQRT:  SQRT% (call-by-register)
          on entry   (S1) = argument
          on exit    (S1) = result

     Vector SQRT:  %SQRT% (call-by-register)
          on entry   (V1) = argument vector
          on exit    (V1) = result vector

     Scalar DSQRT:  DSQRT% (call-by-register)
          on entry   (S1) and (S2) = argument
          on exit    (S1) and (S2) = result
     Vector DSQRT:  %DSQRT% (call-by-register)
          on entry   (V1) and (V2) = argument vector
          on exit    (V1) and (V2) = result vector

     Scalar CSQRT:  CSQRT% (call-by-register)
          on entry   (S1) and (S2) = argument
          on exit    (S1) and (S2) = result

     Vector CSQRT:  %CSQRT% (call-by-register)
          on entry   (V1) and (V2) = argument vector
          on exit    (V1) and (V2) = result vector

   Argument Range
     SQRT, DSQRT:
                                                         2450
          0 <= x < infinity (infinity is approximately 10    )
                                                            308
          On UNICOS/mk systems, infinity is approximately 10

     CSQRT:

          |x | < infinity, |x | < infinity
            r                i
     CDSQRT:

          |x | < infinity, |x | < infinity
            r                i
NOTES
     CDSQRT is an outmoded routine for the CF90 compiler.  Refer to the
     Fortran Language Reference Manual, Volume 3, publication SR-3905, for
     information about outmoded features and their preferred standard
     alternatives.

     The name of the SQRT, DSQRT, and CSQRT intrinsic can be passed as an
     argument.  The name of the CDSQRT intrinsic cannot be passed as an
     argument.

RETURN VALUES
     SQRT returns the real square root of its real argument.

     DSQRT returns the double-precision square root of its double-precision
     argument.

     CSQRT returns the complex square root of its complex argument.

     CDSQRT returns the complex double-precision square root of its complex
     double-precision argument.

     On CRAY T90 systems that support IEEE arithmetic, the following return
     values occur:

          SQRT(0) = 0

          SQRT(-0) = -0

          SQRT(x) = NaN if x < 0

          SQRT(NaN) = NaN

          SQRT( infinity ) = infinity

SEE ALSO
     Intrinsic Procedures Reference Manual, publication SR-2138, for the
     printed version of this man page.