# Utilities to deal with Nucleotide Alphabets

  Functions to cope with various aspects related to the nucleotide sequence alphabet.

  Defines

  VRNA_SEQUENCE_RNA
    #include <ViennaRNA/sequences/sequence.h>
  VRNA_SEQUENCE_DNA
    #include <ViennaRNA/sequences/sequence.h>

  Typedefs

  typedef struct vrna_sequence_s vrna_seq_t
    #include <ViennaRNA/sequences/sequence.h>

    Typename for nucleotide sequence representation data structure vrna_sequence_s.

  typedef struct vrna_alignment_s vrna_msa_t
    #include <ViennaRNA/sequences/sequence.h>

  Enums

  enum vrna_seq_type_e

    A enumerator used in vrna_sequence_s to distinguish different nucleotide sequences.

    Values:

    enumerator VRNA_SEQ_UNKNOWN

      Nucleotide sequence represents an Unkown type.

    enumerator VRNA_SEQ_RNA

      Nucleotide sequence represents an RNA type.

    enumerator VRNA_SEQ_DNA

      Nucleotide sequence represents a DNA type.

  Functions

  unsigned int vrna_sequence_length_max(unsigned int options)
    #include <ViennaRNA/sequences/alphabet.h>
  int vrna_nucleotide_IUPAC_identity(char a, char b)
    #include <ViennaRNA/sequences/alphabet.h>
  void vrna_ptypes_prepare( vrna_fold_compound_t *fc, unsigned int options)
    #include <ViennaRNA/sequences/alphabet.h>
  char *vrna_ptypes(const short *S, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>

    Get an array of the numerical encoding for each possible base pair (i,j)

    See also

    vrna_idx_col_wise(), vrna_fold_compound_t

    Note

    This array is always indexed in column-wise order, in contrast to previously different indexing between mfe and pf variants!

  short *vrna_seq_encode(const char *sequence, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>

    Get a numerical representation of the nucleotide sequence.

    SWIG Wrapper Notes:

      In the target scripting language, this function is wrapped as overloaded function `seq_encode()` where the last parameter, the `model_details` data structure, is optional. If it is omitted, default model settings are applied, i.e. default nucleotide letter conversion. The wrapped function returns a list/tuple of integer representations of the input sequence. See, e.g. `RNA.seq_encode()` in the Python API.

    Parameters:

      - sequence – The input sequence in upper-case letters

      - md – A pointer to a vrna_md_t data structure that specifies the conversion type

    Returns:

      A list of integer encodings for each sequence letter (1-based). Position 0 denotes the length of the list

  short *vrna_seq_encode_simple(const char *sequence, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>

    Get a numerical representation of the nucleotide sequence (simple version)

  int vrna_nucleotide_encode(char c, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>

    Encode a nucleotide character to numerical value.

    This function encodes a nucleotide character to its numerical representation as required by many functions in RNAlib.

    See also

    vrna_nucleotide_decode(), vrna_seq_encode()

    Parameters:

      - c – The nucleotide character to encode

      - md – The model details that determine the kind of encoding

    Returns:

      The encoded nucleotide

  char vrna_nucleotide_decode(int enc, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>

    Decode a numerical representation of a nucleotide back into nucleotide alphabet.

    This function decodes a numerical representation of a nucleotide character back into nucleotide alphabet

    See also

    vrna_nucleotide_encode(), vrna_seq_encode()

    Parameters:

      - enc – The encoded nucleotide

      - md – The model details that determine the kind of decoding

    Returns:

      The decoded nucleotide character

  void vrna_aln_encode(const char *sequence, short **S_p, short **s5_p, short **s3_p, char **ss_p, unsigned int **as_p, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>
  unsigned int vrna_get_ptype_md(int i, int j, vrna_md_t *md)
    #include <ViennaRNA/sequences/alphabet.h>
  unsigned int vrna_get_ptype(int ij, char *ptype)
    #include <ViennaRNA/sequences/alphabet.h>
  unsigned int vrna_get_ptype_window(int i, int j, char **ptype)
    #include <ViennaRNA/sequences/alphabet.h>
  vrna_seq_t *vrna_sequence(const char *string, unsigned int options)
    #include <ViennaRNA/sequences/sequence.h>
  int vrna_sequence_add( vrna_fold_compound_t *fc, const char *string, unsigned int options)
    #include <ViennaRNA/sequences/sequence.h>
  int vrna_sequence_remove( vrna_fold_compound_t *fc, unsigned int i)
    #include <ViennaRNA/sequences/sequence.h>
  void vrna_sequence_remove_all( vrna_fold_compound_t *fc)
    #include <ViennaRNA/sequences/sequence.h>
  void vrna_sequence_prepare( vrna_fold_compound_t *fc)
    #include <ViennaRNA/sequences/sequence.h>
  int vrna_sequence_order_update( vrna_fold_compound_t *fc, const unsigned int *order)
    #include <ViennaRNA/sequences/sequence.h>
  int vrna_msa_add( vrna_fold_compound_t *fc, const char **alignment, const char **names, const unsigned char *orientation, const unsigned long long *start, const unsigned long long *genome_size, unsigned int options)
    #include <ViennaRNA/sequences/sequence.h>
  struct vrna_sequence_s
    #include <ViennaRNA/sequences/sequence.h>

    Data structure representing a nucleotide sequence.

    Public Members

    vrna_seq_type_e type

      The type of sequence.

    char *name
    char *string

      The string representation of the sequence.

    short *encoding

      The integer representation of the sequence.

    short *encoding5
    short *encoding3
    unsigned int length

      The length of the sequence.

  struct vrna_alignment_s

    Public Members

    unsigned int n_seq
    vrna_seq_t *sequences
    char **gapfree_seq
    unsigned int *gapfree_size
    unsigned long long *genome_size
    unsigned long long *start
    unsigned char *orientation
    unsigned int **a2s