Class: Ephem::Segments::BaseSegment

Inherits:
Object
  • Object
show all
Includes:
Core::CalendarCalculations, Core::Constants
Defined in:
lib/ephem/segments/base_segment.rb

Direct Known Subclasses

OrientationSegment, Segment

Constant Summary collapse

TARGET_NAMES = 
{
  Bodies::SOLAR_SYSTEM_BARYCENTER => "Solar System Barycenter",
  Bodies::MERCURY_BARYCENTER => "Mercury Barycenter",
  Bodies::VENUS_BARYCENTER => "Venus Barycenter",
  Bodies::EARTH_MOON_BARYCENTER => "Earth-Moon Barycenter",
  Bodies::MARS_BARYCENTER => "Mars Barycenter",
  Bodies::JUPITER_BARYCENTER => "Jupiter Barycenter",
  Bodies::SATURN_BARYCENTER => "Saturn Barycenter",
  Bodies::URANUS_BARYCENTER => "Uranus Barycenter",
  Bodies::NEPTUNE_BARYCENTER => "Neptune Barycenter",
  Bodies::PLUTO_BARYCENTER => "Pluto Barycenter",
  Bodies::SUN => "Sun",
  Bodies::MERCURY => "Mercury",
  Bodies::VENUS => "Venus",
  Bodies::MOON => "Moon",
  Bodies::EARTH => "Earth",
  Bodies::MARS => "Mars",
  Bodies::JUPITER => "Jupiter",
  Bodies::SATURN => "Saturn",
  Bodies::URANUS => "Uranus",
  Bodies::NEPTUNE => "Neptune",
  Bodies::PLUTO => "Pluto"
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Core::CalendarCalculations

format_date, julian_to_gregorian

Constructor Details

#initialize(daf:, source:, descriptor:) ⇒ BaseSegment

Initialize a new segment

Parameters:

  • daf (Ephem::IO::DAF) —

    the DAF object representing the data file

  • source (String) —

    the source identifier of the segment

  • descriptor (Array) —

    array containing segment descriptors:

    • start_second [Float] start time in seconds from J2000

    • end_second [Float] end time in seconds from J2000

    • target [Integer] target body ID

    • center [Integer] center body ID

    • frame [String] reference frame identifier

    • data_type [Integer] type of data in the segment

    • start_i [Integer] start index in the data array

    • end_i [Integer] end index in the data array



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# File 'lib/ephem/segments/base_segment.rb', line 59

def initialize(daf:, source:, descriptor:)
  @daf = daf
  @source = source
  parse_descriptor(descriptor)
  @start_jd = compute_julian_date(@start_second)
  @end_jd = compute_julian_date(@end_second)
end

Instance Attribute Details

#center ⇒ Integer (readonly)

Returns the center body ID.

Returns:

  • (Integer) —

    the center body ID



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# File 'lib/ephem/segments/base_segment.rb', line 38

def center
  @center
end

#daf ⇒ Ephem::IO::DAF (readonly)

Returns the DAF object representing the data file.

Returns:



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# File 'lib/ephem/segments/base_segment.rb', line 34

def daf
  @daf
end

#end_jd ⇒ Float (readonly)

Returns end of coverage as a Julian Date.

Returns:

  • (Float) —

    end of coverage as a Julian Date



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# File 'lib/ephem/segments/base_segment.rb', line 44

def end_jd
  @end_jd
end

#source ⇒ String (readonly)

Returns the source of the segment.

Returns:

  • (String) —

    the source of the segment



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# File 'lib/ephem/segments/base_segment.rb', line 40

def source
  @source
end

#start_jd ⇒ Float (readonly)

Returns start of coverage as a Julian Date.

Returns:

  • (Float) —

    start of coverage as a Julian Date



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# File 'lib/ephem/segments/base_segment.rb', line 42

def start_jd
  @start_jd
end

#target ⇒ Integer (readonly)

Returns the target body ID.

Returns:

  • (Integer) —

    the target body ID



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# File 'lib/ephem/segments/base_segment.rb', line 36

def target
  @target
end

Instance Method Details

#clear_data ⇒ Object 



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# File 'lib/ephem/segments/base_segment.rb', line 116

def clear_data
  # Placeholder method to clear any cached data
end

#compute(_tdb, _tdb2 = 0.0) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/ephem/segments/base_segment.rb', line 106

def compute(_tdb, _tdb2 = 0.0)
  raise NotImplementedError,
    "#{self.class} has not implemented compute() for data type #{@data_type}"
end

#compute_and_differentiate(_tdb, _tdb2 = 0.0) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/ephem/segments/base_segment.rb', line 111

def compute_and_differentiate(_tdb, _tdb2 = 0.0)
  raise NotImplementedError,
    "#{self.class} has not implemented compute_and_differentiate() for data type #{@data_type}"
end

#covers?(tdb, tdb2 = 0.0) ⇒ Boolean

Whether the given time falls within this segment’s coverage.

Parameters:

  • tdb (Numeric) —

    time in TDB Julian Date

  • tdb2 (Numeric) (defaults to: 0.0) —

    optional fractional part of the TDB date

Returns:

  • (Boolean) 


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# File 'lib/ephem/segments/base_segment.rb', line 102

def covers?(tdb, tdb2 = 0.0)
  (tdb + tdb2).between?(@start_jd, @end_jd)
end

#describe(verbose: false) ⇒ String

Detailed description of the segment

Parameters:

  • verbose (Boolean) (defaults to: false) —

    whether to include additional details

Returns:

  • (String) —

    formatted description of the segment



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# File 'lib/ephem/segments/base_segment.rb', line 78

def describe(verbose: false)
  start_date = format_date(*julian_to_gregorian(@start_jd))
  end_date = format_date(*julian_to_gregorian(@end_jd))

  center_name = get_body_name(@center, "Unknown Center")
  target_name = get_body_name(@target, "Unknown Target")

  dates = "#{start_date}..#{end_date}"
  center = "#{center_name} (#{@center})"
  target = "#{target_name} (#{@target})"
  description = "#{dates} Type #{@data_type} #{center} -> #{target}"
  return description unless verbose

  <<~DESCRIPTION.chomp
    #{description}
    frame=#{@frame} source=#{@source}
  DESCRIPTION
end

#to_s ⇒ String

String representation of the segment

Returns:

  • (String) —

    segment description in non-verbose format



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# File 'lib/ephem/segments/base_segment.rb', line 70

def to_s
  describe(verbose: false)
end