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PDL::Type(3pm) User Contributed Perl Documentation PDL::Type(3pm)

NAME

PDL::Type - Objects encapsulating datatypes for PDL transformations

SYNOPSIS

  $p = pdl('1 2 3');
  print $p->type;
  # double

DESCRIPTION

This module declares one class - of this class The type method of an ndarray returns a "PDL::Type" object. For further examples check again the type method.

Comparison and stringification are overloaded so that you can compare and print type objects, e.g.

  $nofloat = 1 if $pdl->type < float;
  die "must be double" if $type != double;

It has methods to access type information.

METHODS

enum

Returns the number representing this datatype (see get_datatype).

symbol

Returns one of 'PDL_SB', 'PDL_B', 'PDL_S', 'PDL_US', 'PDL_L', 'PDL_UL', 'PDL_IND', 'PDL_ULL', 'PDL_LL', 'PDL_F', 'PDL_D', 'PDL_LD', 'PDL_CF', 'PDL_CD', or 'PDL_CLD'.

ctype

Returns the macro used to represent this type in C code (eg 'PDL_Long').

convertfunc

Lower-case version of the "shortctype".

ppsym

The letter used to represent this type in PP code (eg 'U' for ushort).

realctype

The actual C type used to store this type.

shortctype

The value returned by "ctype" without the 'PDL_' prefix.

badvalue

The special numerical value used to represent bad values for this type. See "badvalue" in PDL::Bad for more details.

isnan

Given a string representing a C value, will return a C expression for this type that indicates whether that value is NaN (for complex values, if either is NaN).

isfinite

Given a string representing a C value, will return a C expression for this type that indicates whether that value is finite (for complex values, if both are finite).

floatsuffix

The string appended to floating-point functions for this floating-point type. Returns "INVALID" if called on non-floating-point type.

orig_badvalue

The default special numerical value used to represent bad values for this type. (You can change the value that represents bad values for each type during runtime.) See the orig_badvalue routine in PDL::Bad for more details.

bswap

Returns the appropriate "bswap*" from PDL::IO::Misc for the size of this type, including a no-op for types of size 1. Note this means a one-line construction means you must call the return value:

  $pdl->type->bswap->($pdl);

real

Returns whether the type is real-only (true) or can hold complex values (false).

  die "Real data only!" if !$pdl->type->real;

unsigned

Returns whether the type can hold signed values (false) or not (true).

integer

Returns whether the type can hold non-integer, a.k.a. floating-point, values (false) or not (true).

2025-01-23 perl v5.40.0