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APL_COMPLEX_AS_V12

Support for Complex Numbers means that some functions produce different results from older Versions of Dyalog APL. If APL_COMPLEX_AS_V12 is set to 1 the behaviour of code developed using Version 12.1 or earlier will be unchanged; in particular:

  • Power (* ) and logarithm (⍟ ) do not produce Complex Numbers as results from non-complex arguments.
  • ⎕VFI will not honour "J" or "j" as part of a number.
  • ¯4○Y will be evaluated as (¯1+Y*2)*0.5 , which is positive for negative real arguments.

If APL_COMPLEX_AS_V12 is set to any other value or is not set at all then code developed using version 12.1 or earlier may now generate Complex Numbers.

In addition, if APL_COMPLEX_AS_V12 is set to 1, objects containing complex numbers cannot be transferred to or from component files, TCP/IP (CONGA), or auxiliary processors and may not be used as an argument to Serialise/Deserialise Array (220⌶ ). Instead, a DOMAIN ERROR will be issued.

This feature is provided to simplify the transition of older code to currently-supported versions of Dyalog. It does not prevent the generation and use of complex numbers using newer features (such as explicitly specifying a complex number literal), and the intention is that it will be removed in a future release of Dyalog.