CHRPAK
Characters and Strings

CHRPAK is a MATLAB library which can handle characters and strings.

CHRPAK began when I simply wanted to be able to capitalize a string. Now it has expanded to a number of interesting uses. Many unusual situations are provided for, including

• string '31.2' <=> numeric value 31.2;
• uppercase <=> lowercase;
• removal of control characters or blanks;
• sorting, merging, searching.

Many of the routine names begin with the name of the data type they operate on:

• B4 - a 4 byte word;
• CH - a character;
• CHVEC - a vector of characters;
• DEC - a decimal fraction;
• DIGIT - a character representing a numeric digit;
• I4 - an integer;
• R4 - a single precision real;
• R8 - a double precision real;
• RAT - a ratio I/J;
• S - a string;
• SVEC - a vector of strings;
• SVECI - a vector of strings, implicitly capitalized;

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

CHRPAK is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Software and Data:

CAESAR, a MATLAB library which can apply a Caesar Shift Cipher to a string of text.

chrpak_test

ROT13, a MATLAB library which can encipher a string using the ROT13 cipher for letters, and the ROT5 cipher for digits.

Reference:

1. Carl Branden, John Tooze,
   Introduction to Protein Structure,
   Second Edition,
   Garland Publishing, 1999,
   ISBN: 0815323050,
   LC: QP551.B7635.
2. Paul Bratley, Bennett Fox, Linus Schrage,
   A Guide to Simulation,
   Second Edition,
   Springer, 1987,
   ISBN: 0387964673,
   LC: QA76.9.C65.B73.
3. IEEE Standards Committee 754,
   IEEE Standard for Binary Floating Point Arithmetic,
   ANSI/IEEE Standard 754-1985,
   SIGPLAN Notices,
   Volume 22, Number 2, 1987, pages 9-25.
4. Donald Knuth,
   The Art of Computer Programming,
   Volume 3, Sorting and Searching,
   Second Edition,
   Addison Wesley, 1998,
   ISBN: 0201896850,
   LC: QA76.6.K64.
5. Albert Nijenhuis, Herbert Wilf,
   Combinatorial Algorithms for Computers and Calculators,
   Academic Press, 1978,
   ISBN: 0-12-519260-6,
   LC: QA164.N54.

Source Code:

• a_to_i4.m returns the index of an alphabetic character;
• base_to_i4.m returns the value of an integer represented in some base;
• binary_to_i4.m converts a binary representation into an integer value;
• binary_to_r8.m converts a binary representation into a real value;
• ch_cap.m returns the capitalized version of a character;
• ch_eqi.m returns TRUE if a two characters are equal (ignoring case);
• ch_extract.m extracts the next nonblank character from a string;
• ch_index.m returns the first occurrence of a character in a string;
• ch_index_last.m returns the last occurrence of a character in a string;
• ch_indexi.m returns the first occurrence of a character in a string, without regard to case;
• ch_is_alpha.m returns TRUE if a character is alphabetic;
• ch_is_alphanumeric.m returns TRUE if a character is alphanumeric;
• ch_is_control.m returns TRUE if a character is a control character;
• ch_is_digit.m returns TRUE if a character is a decimal digit;
• ch_is_format_code.m returns TRUE if a character is a legal FORTRAN format code;
• ch_is_isbn_digit.m returns TRUE if a character is an ISBN digit;
• ch_is_lower.m returns TRUE if a character is a lowercase alphabetic character;
• ch_is_printable.m determines if a character is printable;
• ch_is_space.m determines if a character is a "whitespace" character;
• ch_is_upper.m returns TRUE if a character is an uppercase alphabetic character;
• ch_low.m returns returns the lowercase version of a character;
• ch_roman_to_i4.m returns the integer value of a single digit of a Roman numeral;
• ch_scrabble.m returns the character on a given Scrabble tile;
• ch_scrabble_frequency.m returns the Scrabble frequency of a character;
• ch_scrabble_points.m returns the Scrabble point value of a character;
• ch_scrabble_select.m selects a character with the Scrabble probability;
• ch_swap.m swaps two characters;
• ch_to_amino_name.m converts a character to an amino acid name;
• ch_to_digit.m converts a character to a digit;
• ch_to_digit_bin.m converts a character to a binary digit;
• ch_to_digit_oct.m, converts a character to an octal digit;
• ch_to_ebcdic.m, converts a character to EBCDIC;
• ch_to_military.m, converts a character to its military encoding;
• ch_to_rot13.m, converts a character to its ROT13 encoding;
• ch_to_scrabble.m, returns the Scrabble index of a character;
• ch_to_soundex.m, converts an ASCII character to a Soundex character;
• ch_uniform.m, returns a random character in a given range;
• chvec_permute.m, permutes the entries of a character vector;
• chvec_print.m, prints the entries in a character vector;
• chvec_reverse.m, reverses the order of the entries in a character vector;
• chvec2_reverse.m, prints the entries in a pair of character vectors;
• degrees_to_radians.m, converts an angle from degrees to radians.
• digit_bin_to_ch.m, returns the character equivalent of a binary digit;
• digit_dec.m, decrements a decimal digit;
• digit_inc.m, increments a decimal digit;
• digit_oct_to_ch.m, returns the character equivalent of an octal digit;
• digit_to_ch.m, converts a digit to a character;
• file_name_inc.m, "increments" a file name;
• hex_digit_to_i4.m converts a hexadecimal digit to an I4;
• hex_to_binary_digits.m, converts a hexadecimal digit to binary digits;
• hex_to_binary_string.m, converts a hexadecimal string to a binary string.
• hex_to_i4.m, converts a hexadecimal string to an I4;
• i4_huge.m, returns a huge I4;
• i4_length.m, computes the number of characters needed to print an I4.
• i4_swap.m, swaps two integer values;
• i4_to_a.m, returns the I-th alphabetic character;
• i4_to_amino_code.m, converts an integer to an amino code. returns the I-th alphabetic character;
• i4_to_base.m converts an I4 to a representation in any base from 1 to 16.
• i4_to_binary.m produces the binary representation of an integer.
• i4_to_binhex.m returns the I-th character in the BINHEX encoding.
• i4_to_hex.m converts an I4 to a string of hexadecimal characters.
• i4_to_hex_digit.m, converts a (small) I4 to a hex digit.
• i4_to_isbn_digit.m, converts an I4 to an ISBN digit;
• i4_to_month_name.m returns the I-th month name;
• i4_to_nunary.m produces the "base -1" representation of an integer.
• i4_to_octal.m converts an I4 to a string of octal characters.
• i4_to_s_left.m converts an integer to a (left justified) string;
• i4_to_s_roman.m returns the Roman numeral representation of I;
• i4_to_s_zero.m converts an integer to a right-justified string padded with zeros;
• i4_to_s32.m converts an I4 to an S32.
• i4_to_unary.m, produces the "base 1" representation of an I4.
• i4_to_uudecode.m, returns the I-th character in the UUDECODE encoding.
• i4_to_xxdecode.m, returns the I-th character in the XXDECODE encoding.
• i4_uniform_ab.m, returns a random integer in a given range;
• i4vec_print.m, prints an I4VEC.
• ic_to_ibraille.m, converts an ASCII integer code to a Braille code.
• ic_to_iebcdic.m, converts an ASCII character code to an EBCDIC code.
• ic_to_imorse.m, converts an ASCII character code to a Morse integer code.
• ic_to_isoundex.m, converts an ASCII integer code to a Soundex integer code.
• iebcdic_to_ic.m, converts an EBCDIC character code to ASCII.
• isbn_digit_to_i4.m, converts an ISBN digit to an I4.
• matlab_real_to_binary_string.m, converts a MATLAB real number to a binary string;
• matlab_real_to_hex_string.m, converts a MATLAB real number to a hexadecimal string;
• oct_to_i4.m, converts an octal string to an I4;
• r4_to_s_left.m, writes an R4 into a (left justified) string;
• r4_uniform_01.m, returns a unit pseudorandom R4.
• r8_to_s_left.m, writes an R8 into a (left justified) string;
• r8_uniform_01.m, returns a unit pseudorandom R8.
• s_alpha_last.m, returns the location of the last alphabetic character in a string;
• s_adjustl.m, shifts a string to the left, "squeezing" out blanks;
• s_adjustr.m, shifts a string to the right, "squeezing" out blanks;
• s_begin.m, is TRUE if two strings match, up to the end of the shorter string, ignoring spaces and capitalization;
• s_behead_substring.m, removes the head of a string, if it matches a given substring;
• s_blank_delete.m, deletes every blank from a string;
• s_blanks_delete.m, replaces consecutive blanks by one blank in a string;
• s_cap.m, capitalizes all the characters in a string;
• s_cat.m, concatenates two strings;
• s_ch_delete.m, removes all occurrences of a character from a string.
• s_compare.m compares two strings, returning -1, 0, or +1.
• s_control_blank.m replaces control characters by blanks in a string.
• s_digits_count.m counts the decimal digits in a string.
• s_eqi.m, is TRUE if two strings are equal, ignoring case and trailing blanks;
• s_escape_tex.m, de-escapes TeX escape sequences;
• s_first_nonblank.m indexes the first nonblank character in a string;
• s_inc_c.m "increments" the characters in a string;
• s_index.m returns the index of the first occurrence of a substring in a string;
• s_is_alpha.m is TRUE if all characters in the string are alphabetic;
• s_len_trim.m returns the length of a string to the last nonblank;
• s_low.m makes a lowercase copy of a string;
• s_neqi.m is TRUE if two strings are not equal, ignoring case and trailing blanks;
• s_nonalpha_delete.m removes nonalphabetic characters from a string.
• s_quote.m quotes a string;
• s_replace_ch.m replaces all occurrences of one character by another;
• s_replace_ch_by_s.m replaces all occurrences of a character by a string;
• s_reverse.m reverses a string;
• s_s_subanagram.m determines if S2 is a "subanagram" of S1.
• s_s_subanagram_sorted.m determines if S2 is a "subanagram" of S1.
• s_scrabble_points.m determines the Scrabble value of a string.
• s_sort_a.m sorts a string into ascending order.
• s_swap.m swaps two strings;
• s_to_caesar.m applies a Caesar shift ciper to a string.
• s_to_digits.m extracts the decimal digits from a string.
• s_to_format.m converts a string to a FORTRAN format;
• s_to_i4.m converts a string to an integer;
• s_to_i4vec.m converts a string to an integer vector;
• s_to_isbn_digits.m extracts ISBN digits from a string.
• s_to_l4.m converts a string to a logical value;
• s_to_r4.m reads an R4 from a string;
• s_to_r8.m reads an R8 from a string;
• s_to_r8vec.m reads an R8VEC from a string;
• s_to_rot13.m encodes or decodes a string using ROT13;
• s_word_count.m counts the number of "words" in a string;
• s_word_extract_first.m extracts the first word from a string;
• sort_heap_external.m externally sorts a list of values into ascending order;
• timestamp.m prints the current HMSDMY date as a timestamp;
• word_next_read.m reads words from a string, one at a time.