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 FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

Reference:

Carl Branden, John Tooze,
Introduction to Protein Structure,
Second Edition,
Garland Publishing, 1999,
ISBN: 0815323050,
LC: QP551.B7635.
Paul Bratley, Bennett Fox, Linus Schrage,
A Guide to Simulation,
Second Edition,
Springer, 1987,
ISBN: 0387964673,
LC: QA76.9.C65.B73.
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.
Donald Knuth,
The Art of Computer Programming,
Volume 3, Sorting and Searching,
Second Edition,
Addison Wesley, 1998,
ISBN: 0201896850,
LC: QA76.6.K64.
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_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.m, converts an I4 to its ISBN representation;
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.m, returns a random integer in a given range;
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_to_i4.m, converts an ISBN character 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_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_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_sort_a.m sorts a string into ascending order.
s_swap.m swaps two strings;
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_l.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.

Examples and Tests:

chrpak_test.m calls all the other test routines;
chrpak_test_output.txt the output file;
chrpak_test001.m tests A_TO_I4 and I4_TO_A;
chrpak_test005.m tests BASE_TO_I4 and I4_TO_BASE;
chrpak_test006.m tests BINARY_TO_I4 and I4_TO_BINARY;
chrpak_test011.m tests CH_CAP;
chrpak_test016.m tests CH_LOW;
chrpak_test021.m tests CH_TO_DIGIT and DIGIT_TO_CH;
chrpak_test022.m tests I4_TO_HEX_DIGIT and HEX_DIGIT_TO_I4;
chrpak_test026.m tests CH_TO_ROT13;
chrpak_test029.m tests CH_UNIFORM;
chrpak_test046.m tests HEX_TO_I4 and I4_TO_HEX;
chrpak_test051.m tests I4_LENGTH;
chrpak_test054.m tests I4_TO_BINHEX;
chrpak_test056.m tests I4_TO_NUNARY;
chrpak_test057.m tests I4_TO_OCT and OCT_TO_I4;
chrpak_test065.m tests I4_TO_UNARY;
chrpak_test066.m tests I4_TO_UUDECODE;
chrpak_test067.m tests I4_TO_XXDECODE;
chrpak_test083.m tests R4_TO_S_LEFT and S_TO_R4;
chrpak_test090.m tests S_BEGIN;
chrpak_test091.m tests S_BEHEAD_SUBSTRING;
chrpak_test1015.m tests S_EQI;
chrpak_test102.m tests S_ESCAPE_TEX;
chrpak_test105.m tests S_INC_C;
chrpak_test115.m tests S_REPLACE_CH;
chrpak_test1155.m tests S_REPLACE_CH_BY_S;
chrpak_test1225.m tests S_S_SUBANAGRAM;
chrpak_test1255.m tests S_SORT_A;
chrpak_test129.m tests S_TO_FORMAT;
chrpak_test137.m tests S_WORD_COUNT;
chrpak_test138.m tests S_WORD_EXTRACT_FIRST;

You can go up one level to the MATLAB source codes.