Returns the secondary structure by one-letter code.

Raises IndexError if #code is invalid. See #code for a list of codes.

SecondaryStructure['H'] # => SecondaryStructure::RightHandedHelixAlpha
SecondaryStructure['h'] # => SecondaryStructure::LeftHandedHelixAlpha
SecondaryStructure['E'] # => SecondaryStructure::BetaStrand
SecondaryStructure['e'] # => SecondaryStructure::BetaStrand
SecondaryStructure['X'] # raises IndexError

Returns the secondary structure by one-letter code.

Returns nil if #code is invalid. See #code for a list of codes.

SecondaryStructure['H']? # => SecondaryStructure::RightHandedHelixAlpha
SecondaryStructure['h']? # => SecondaryStructure::LeftHandedHelixAlpha
SecondaryStructure['E']? # => SecondaryStructure::BetaStrand
SecondaryStructure['e']? # => SecondaryStructure::BetaStrand
SecondaryStructure['X']? # => nil

Returns one-letter secondary structure code.

Codes are a superset of those defined by DSSP:

• 'I' : Right-handed π-helix (5-turn)
• 'H' : Right-handed α-helix (4-turn)
• 'G' : Right-handed 3₁₀-helix (3-turn)
• 'F' : Right-handed 2.2₇ (2-turn)
• 'i' : Left-handed π-helix (5-turn)
• 'h' : Left-handed α-helix (4-turn)
• 'g' : Left-handed 3₁₀-helix (3-turn)
• 'f' : Left-handed 2.2₇ (2-turn)
• 'P' : Polyproline
• 'E' : β-strand
• 'B' : β-bridge
• 'T' : Turn
• 'S' : Bend
• '0' : None

Returns true if secondary structures are equal.

If strict is true, secondary structures are compared by their identity, otherwise they're compared by their computed type.

SecondaryStructure::RightHandedHelixAlpha.equals?(:right_handed_helix_alpha) # => true
SecondaryStructure::RightHandedHelixAlpha.equals?(:right_handed_helix_pi)    # => false
SecondaryStructure::RightHandedHelixAlpha.equals?(:left_handed_helix_alpha)  # => false
SecondaryStructure::BetaStrand.equals?(:polyproline)                         # => true
SecondaryStructure::BetaStrand.equals?(:bend)                                # => false

SecondaryStructure::RightHandedHelixAlpha.equals?(:right_handed_helix_pi, strict: false) # => true
SecondaryStructure::BetaStrand.equals?(:polyproline, strict: false)                      # => true
SecondaryStructure::BetaStrand.equals?(:bend, strict: false)                             # => false

Returns nominal secondary structure's minimum size.

Returns true if it's a regular secondary structure, otherwise false.

See also SecondaryStructureType#regular?.

SecondaryStructure::RightHandedHelixAlpha.regular? # => true
SecondaryStructure::LeftHandedHelixAlpha.regular?  # => true
SecondaryStructure::BetaStrand.regular?            # => true
SecondaryStructure::Turn.regular?                  # => false
SecondaryStructure::Bend.regular?                  # => false

Returns secondary structure type.

SecondaryStructure::RightHandedHelixAlpha.type # => Helical
SecondaryStructure::LeftHandedHelixAlpha.type  # => Helical
SecondaryStructure::BetaStrand.type            # => Extended
SecondaryStructure::Turn.type                  # => Coil
SecondaryStructure::Bend.type                  # => Coil