Astro-FITS-Header

 view release on metacpan or  search on metacpan

Changes  view on Meta::CPAN

  - New append() method to append a header or items to an existing
    header, overwriting duplicates.

  - A header can now be constructed from a simple perl hash

  - Item objects now have a copy constructor.

  - When importing an AST frameset a specific encoding can be
    specified.

  - The Item constructor can now guess the header type.

  - Fixes in item removal, tied interface for history and subheaders
    and NDF opening when a directory has a space.

3.0 2006-08-19

 - Can now select items by type using the itembytype() method.

 - Add equals() method.

lib/Astro/FITS/Header/Item.pm  view on Meta::CPAN

Used to specify the value associated with this FITS item.

=item B<Comment>

Used to specify the comment associated with this FITS item.

=item B<Type>

Used to specify the variable type. See the C<type> method
for more details. A type will be guessed if one is not supplied.
The guess may well be wrong.

=back

Does nothing if these keys are not supplied.

=cut

sub configure {
  my $self = shift;
  my %hash = @_;

lib/Astro/FITS/Header/Item.pm  view on Meta::CPAN

    # only set type if we have not been given a type
    if (!$self->type) {
      if (!$self->keyword && !$self->value) {
	# completely blank
	$self->type("BLANK");
      } elsif (!$self->keyword || $self->keyword =~ /^(COMMENT|HISTORY)$/) {
	# COMMENT, HISTORY, and blank cards are special
	$self->type('COMMENT')
      } else {
        my $type = $self->guess_type( $self->value );
        $self->type( $type ) if defined $type;
      }
    }

    # End cards are special, need only do a Keyword => 'END' to configure
    $self->type('END') if $self->keyword() eq 'END';
  }
}

=item B<freeze>

lib/Astro/FITS/Header/Item.pm  view on Meta::CPAN

  } else {
    # A real keyword/value so add the "= "
    $card .= "= ";

    # Try to sort out the type if we havent got one
    # We can not find LOGICAL this way since we can't
    # tell the difference between 'F' and F
    # an undefined value is typeless
    unless (defined $type) {
      $type = $self->guess_type( $value );
    }

    # Numbers behave identically whether they are float or int
    # Logical is a number formatted as a "T" or "F"
    if ($type eq 'INT' or $type eq 'FLOAT' or $type eq 'LOGICAL' or
       $type eq 'UNDEF') {

      # Change the value for logical
      if ($type eq 'LOGICAL') {
	$value = ( ($value && ($value ne 'F')) ? 'T' : 'F' );

lib/Astro/FITS/Header/Item.pm  view on Meta::CPAN

    $card = substr($card,0,80);
    $card .= ' 'x(80-length($card));

  }

  # Return the result
  return $card;

}

=item B<guess_type>

This class method can be used to guess the data type of a supplied value.
It is private but can be used by other classes in the Astro::FITS::Header
hierarchy.

 $type = Astro::FITS::Header::Item->guess_type( $value );

Can not distinguish a string F from a LOGICAL F so will always guess
"string". Returns "string" if a type could not be determined.

=cut

sub guess_type {
  my $self = shift;
  my $value = shift;
  my $type;
  if (!defined $value) {
    $type = "UNDEF";
  } elsif ($value =~ /^\d+$/) {
    $type = "INT";
  } elsif ($value =~ /^(-?)(\d*)(\.?)(\d*)([EeDd][-\+]?\d+)?$/) {
    $type = "FLOAT";
  } else {