(octave.info)Simple File I/O


Prev: Terminal Input Up: Basic Input and Output
Enter node , (file) or (file)node

14.1.3 Simple File I/O
----------------------

The ‘save’ and ‘load’ commands allow data to be written to and read from
disk files in various formats.  The default format of files written by
the ‘save’ command can be controlled using the functions
‘save_default_options’ and ‘save_precision’.

   As an example the following code creates a 3-by-3 matrix and saves it
to the file ‘myfile.mat’.

     A = [ 1:3; 4:6; 7:9 ];
     save myfile.mat A

   Once one or more variables have been saved to a file, they can be
read into memory using the ‘load’ command.

     load myfile.mat
     A
          ⊣ A =
          ⊣
          ⊣    1   2   3
          ⊣    4   5   6
          ⊣    7   8   9

 -- : save file
 -- : save options file
 -- : save options file V1 V2 ...
 -- : save options file -struct STRUCT
 -- : save options file -struct STRUCT F1 F2 ...
 -- : save - V1 V2 ...
 -- : STR = save ("-", "V1", "V2", ...)
     Save the named variables V1, V2, ..., in the file FILE.

     The special filename ‘-’ may be used to return the content of the
     variables as a string.  If no variable names are listed, Octave
     saves all the variables in the current scope.  Otherwise, full
     variable names or pattern syntax can be used to specify the
     variables to save.  If the ‘-struct’ modifier is used then the
     fields of the *scalar* struct are saved as if they were variables
     with the corresponding field names.  The ‘-struct’ option can be
     combined with specific field names F1, F2, ... to write only
     certain fields to the file.

     Valid options for the ‘save’ command are listed in the following
     table.  Options that modify the output format override the format
     specified by ‘save_default_options’.

     If save is invoked using the functional form

          save ("-option1", ..., "file", "v1", ...)

     then the OPTIONS, FILE, and variable name arguments (V1, ...) must
     be specified as character strings.

     If called with a filename of "-", write the output to stdout if
     nargout is 0, otherwise return the output in a character string.

     ‘-append’
          Append to the destination instead of overwriting.

     ‘-ascii’
          Save a matrix in a text file without a header or any other
          information.  The matrix must be 2-D and only the real part of
          any complex value is written to the file.  Numbers are stored
          in single-precision format and separated by spaces.
          Additional options for the ‘-ascii’ format are

          ‘-double’
               Store numbers in double-precision format.

          ‘-tabs’
               Separate numbers with tabs.

     ‘-binary’
          Save the data in Octave’s binary data format.

     ‘-float-binary’
          Save the data in Octave’s binary data format but using only
          single precision.  Use this format *only* if you know that all
          the values to be saved can be represented in single precision.

     ‘-hdf5’
          Save the data in HDF5 format.  (HDF5 is a free, portable,
          binary format developed by the National Center for
          Supercomputing Applications at the University of Illinois.)
          This format is only available if Octave was built with a link
          to the HDF5 libraries.

     ‘-float-hdf5’
          Save the data in HDF5 format but using only single precision.
          Use this format *only* if you know that all the values to be
          saved can be represented in single precision.

     ‘-V7’
     ‘-v7’
     ‘-7’
     ‘-mat7-binary’
          Save the data in MATLAB’s v7 binary data format.

     ‘-V6’
     ‘-v6’
     ‘-6’
     ‘-mat’
     ‘-mat-binary’
          Save the data in MATLAB’s v6 binary data format.

     ‘-V4’
     ‘-v4’
     ‘-4’
     ‘-mat4-binary’
          Save the data in the binary format written by MATLAB version
          4.

     ‘-text’
          Save the data in Octave’s text data format.  (default).

     ‘-zip’
     ‘-z’
          Use the gzip algorithm to compress the file.  This works on
          files that are compressed with gzip outside of Octave, and
          gzip can also be used to convert the files for backward
          compatibility.  This option is only available if Octave was
          built with a link to the zlib libraries.

     The list of variables to save may use wildcard patterns containing
     the following special characters:

     ‘?’
          Match any single character.

     ‘*’
          Match zero or more characters.

     ‘[ LIST ]’
          Match the list of characters specified by LIST.  If the first
          character is ‘!’ or ‘^’, match all characters except those
          specified by LIST.  For example, the pattern ‘[a-zA-Z]’ will
          match all lower and uppercase alphabetic characters.

          Wildcards may also be used in the field name specifications
          when using the ‘-struct’ modifier (but not in the struct name
          itself).

     Except when using the MATLAB binary data file format or the
     ‘-ascii’ format, saving global variables also saves the global
     status of the variable.  If the variable is restored at a later
     time using ‘load’, it will be restored as a global variable.

     The command

          save -binary data a b*

     saves the variable ‘a’ and all variables beginning with ‘b’ to the
     file ‘data’ in Octave’s binary format.

     See also: Note: load, *note save_default_options:
     XREFsave_default_options, *note save_header_format_string:
     XREFsave_header_format_string, *note save_precision:
     XREFsave_precision, Note: dlmread, *note csvread:
     XREFcsvread, Note: fread.

   There are three functions that modify the behavior of ‘save’.

 -- : VAL = save_default_options ()
 -- : OLD_VAL = save_default_options (NEW_VAL)
 -- : save_default_options (NEW_VAL, "local")
     Query or set the internal variable that specifies the default
     options for the ‘save’ command, and defines the default format.

     The default value is "-text" (Octave’s own text-based file format).
     See the documentation of the ‘save’ command for other choices.

     When called from inside a function with the "local" option, the
     variable is changed locally for the function and any subroutines it
     calls.  The original variable value is restored when exiting the
     function.

     See also: Note: save, *note save_header_format_string:
     XREFsave_header_format_string, *note save_precision:
     XREFsave_precision.

 -- : VAL = save_precision ()
 -- : OLD_VAL = save_precision (NEW_VAL)
 -- : save_precision (NEW_VAL, "local")
     Query or set the internal variable that specifies the number of
     digits to keep when saving data in text format.

     The default value is 17 which is the minimum necessary for the
     lossless saving and restoring of IEEE-754 double values; For
     IEEE-754 single values the minimum value is 9.  If file size is a
     concern, it is probably better to choose a binary format for saving
     data rather than to reduce the precision of the saved values.

     When called from inside a function with the "local" option, the
     variable is changed locally for the function and any subroutines it
     calls.  The original variable value is restored when exiting the
     function.

     See also: Note: save_default_options.

 -- : VAL = save_header_format_string ()
 -- : OLD_VAL = save_header_format_string (NEW_VAL)
 -- : save_header_format_string (NEW_VAL, "local")
     Query or set the internal variable that specifies the format string
     used for the comment line written at the beginning of text-format
     data files saved by Octave.

     The format string is passed to ‘strftime’ and must begin with the
     character ‘#’ and contain no newline characters.  If the value of
     ‘save_header_format_string’ is the empty string, the header comment
     is omitted from text-format data files.  The default value is

          "# Created by Octave VERSION, %a %b %d %H:%M:%S %Y %Z <USER@HOST>"

     When called from inside a function with the "local" option, the
     variable is changed locally for the function and any subroutines it
     calls.  The original variable value is restored when exiting the
     function.

     See also: Note: strftime, *note save_default_options:
     XREFsave_default_options.

 -- : load file
 -- : load options file
 -- : load options file v1 v2 ...
 -- : S = load ("options", "file", "v1", "v2", ...)
 -- : load file options
 -- : load file options v1 v2 ...
 -- : S = load ("file", "options", "v1", "v2", ...)
     Load the named variables V1, V2, ..., from the file FILE.

     If no variables are specified then all variables found in the file
     will be loaded.  As with ‘save’, the list of variables to extract
     can be full names or use a pattern syntax.  The format of the file
     is automatically detected but may be overridden by supplying the
     appropriate option.

     If load is invoked using the functional form

          load ("-option1", ..., "file", "v1", ...)

     then the OPTIONS, FILE, and variable name arguments (V1, ...) must
     be specified as character strings.

     If a variable that is not marked as global is loaded from a file
     when a global symbol with the same name already exists, it is
     loaded in the global symbol table.  Also, if a variable is marked
     as global in a file and a local symbol exists, the local symbol is
     moved to the global symbol table and given the value from the file.

     If invoked with a single output argument, Octave returns data
     instead of inserting variables in the symbol table.  If the data
     file contains only numbers (TAB- or space-delimited columns), a
     matrix of values is returned.  Otherwise, ‘load’ returns a
     structure with members corresponding to the names of the variables
     in the file.

     The ‘load’ command can read data stored in Octave’s text and binary
     formats, and MATLAB’s binary format.  If compiled with zlib
     support, it can also load gzip-compressed files.  It will
     automatically detect the type of file and do conversion from
     different floating point formats (currently only IEEE big and
     little endian, though other formats may be added in the future).

     Valid options for ‘load’ are listed in the following table.

     ‘-force’
          This option is accepted for backward compatibility but is
          ignored.  Octave now overwrites variables currently in memory
          with those of the same name found in the file.

     ‘-ascii’
          Force Octave to assume the file contains columns of numbers in
          text format without any header or other information.  Data in
          the file will be loaded as a single numeric matrix with the
          name of the variable derived from the name of the file.

     ‘-binary’
          Force Octave to assume the file is in Octave’s binary format.

     ‘-hdf5’
          Force Octave to assume the file is in HDF5 format.  (HDF5 is a
          free, portable binary format developed by the National Center
          for Supercomputing Applications at the University of
          Illinois.)  Note that Octave can read HDF5 files not created
          by itself, but may skip some datasets in formats that it
          cannot support.  This format is only available if Octave was
          built with a link to the HDF5 libraries.

     ‘-import’
          This option is accepted for backward compatibility but is
          ignored.  Octave can now support multi-dimensional HDF data
          and automatically modifies variable names if they are invalid
          Octave identifiers.

     ‘-mat’
     ‘-mat-binary’
     ‘-6’
     ‘-v6’
     ‘-7’
     ‘-v7’
          Force Octave to assume the file is in MATLAB’s version 6 or 7
          binary format.

     ‘-mat4-binary’
     ‘-4’
     ‘-v4’
     ‘-V4’
          Force Octave to assume the file is in the binary format
          written by MATLAB version 4.

     ‘-text’
          Force Octave to assume the file is in Octave’s text format.

     See also: Note: save, Note: dlmwrite, Note:
     csvwrite, Note: fwrite.

 -- : STR = fileread (FILENAME)
     Read the contents of FILENAME and return it as a string.

     See also: Note: fread, Note: textread,
     Note: sscanf.

 -- : native_float_format ()
     Return the native floating point format as a string.

   It is possible to write data to a file in a similar way to the ‘disp’
function for writing data to the screen.  The ‘fdisp’ works just like
‘disp’ except its first argument is a file pointer as created by
‘fopen’.  As an example, the following code writes to data ‘myfile.txt’.

     fid = fopen ("myfile.txt", "w");
     fdisp (fid, "3/8 is ");
     fdisp (fid, 3/8);
     fclose (fid);

Note: Opening and Closing Files, for details on how to use ‘fopen’ and
‘fclose’.

 -- : fdisp (FID, X)
     Display the value of X on the stream FID.

     For example:

          fdisp (stdout, "The value of pi is:"), fdisp (stdout, pi)

               ⊣ the value of pi is:
               ⊣ 3.1416

     Note that the output from ‘fdisp’ always ends with a newline.

     See also: Note: disp.

   Octave can also read and write matrices text files such as comma
separated lists.

 -- : dlmwrite (FILE, M)
 -- : dlmwrite (FILE, M, DELIM, R, C)
 -- : dlmwrite (FILE, M, KEY, VAL ...)
 -- : dlmwrite (FILE, M, "-append", ...)
 -- : dlmwrite (FID, ...)
     Write the numeric matrix M to the text file FILE using a delimiter.

     FILE should be a filename or a writable file ID given by ‘fopen’.

     The parameter DELIM specifies the delimiter to use to separate
     values on a row.  If no delimiter is specified the comma character
     ‘,’ is used.

     The value of R specifies the number of delimiter-only lines to add
     to the start of the file.

     The value of C specifies the number of delimiters to prepend to
     each line of data.

     If the argument "-append" is given, append to the end of FILE.

     In addition, the following keyword value pairs may appear at the
     end of the argument list:

     "append"
          Either "on" or "off".  See "-append" above.

     "delimiter"
          See DELIM above.

     "newline"
          The character(s) to separate each row.  Three special cases
          exist for this option.  "unix" is changed into "\n", "pc" is
          changed into "\r\n", and "mac" is changed into "\r".  Any
          other value is used directly as the newline separator.

     "roffset"
          See R above.

     "coffset"
          See C above.

     "precision"
          The precision to use when writing the file.  It can either be
          a format string (as used by fprintf) or a number of
          significant digits.

          dlmwrite ("file.csv", reshape (1:16, 4, 4));

          dlmwrite ("file.tex", a, "delimiter", "&", "newline", "\n")

     See also: Note: dlmread, Note: csvread,
     Note: csvwrite.

 -- : DATA = dlmread (FILE)
 -- : DATA = dlmread (FILE, SEP)
 -- : DATA = dlmread (FILE, SEP, R0, C0)
 -- : DATA = dlmread (FILE, SEP, RANGE)
 -- : DATA = dlmread (..., "emptyvalue", EMPTYVAL)
     Read numeric data from the text file FILE which uses the delimiter
     SEP between data values.

     If SEP is not defined the separator between fields is determined
     from the file itself.

     The optional scalar arguments R0 and C0 define the starting row and
     column of the data to be read.  These values are indexed from zero,
     i.e., the first data row corresponds to an index of zero.

     The RANGE parameter specifies exactly which data elements are read.
     The first form of the parameter is a 4-element vector containing
     the upper left and lower right corners ‘[R0,C0,R1,C1]’ where the
     indices are zero-based.  Alternatively, a spreadsheet style form
     such as "A2..Q15" or "T1:AA5" can be used.  The lowest alphabetical
     index ’A’ refers to the first column.  The lowest row index is 1.

     FILE should be a filename or a file id given by ‘fopen’.  In the
     latter case, the file is read until end of file is reached.

     The "emptyvalue" option may be used to specify the value used to
     fill empty fields.  The default is zero.  Note that any non-numeric
     values, such as text, are also replaced by the "emptyvalue".

     See also: Note: csvread, Note: textscan,
     Note: textread, Note: dlmwrite.

 -- : csvwrite (FILENAME, X)
 -- : csvwrite (FILENAME, X, DLM_OPT1, ...)
     Write the numeric matrix X to the file FILENAME in
     comma-separated-value (CSV) format.

     This function is equivalent to

          dlmwrite (FILENAME, X, ",", DLM_OPT1, ...)

     Any optional arguments are passed directly to ‘dlmwrite’ (Note:
     dlmwrite.).

     See also: Note: csvread, Note: dlmwrite,
     Note: dlmread.

 -- : X = csvread (FILENAME)
 -- : X = csvread (FILENAME, DLM_OPT1, ...)
     Read the comma-separated-value (CSV) file FILENAME into the matrix
     X.

     Note: only CSV files containing numeric data can be read.

     This function is equivalent to

          X = dlmread (FILENAME, "," , DLM_OPT1, ...)

     Any optional arguments are passed directly to ‘dlmread’ (Note:
     dlmread.).

     See also: Note: dlmread, Note: textread,
     Note: textscan, Note: csvwrite, Note:
     dlmwrite.

   Formatted data from can be read from, or written to, text files as
well.

 -- : [A, ...] = textread (FILENAME)
 -- : [A, ...] = textread (FILENAME, FORMAT)
 -- : [A, ...] = textread (FILENAME, FORMAT, N)
 -- : [A, ...] = textread (FILENAME, FORMAT, PROP1, VALUE1, ...)
 -- : [A, ...] = textread (FILENAME, FORMAT, N, PROP1, VALUE1, ...)
     Read data from a text file.

     The file FILENAME is read and parsed according to FORMAT.  The
     function behaves like ‘strread’ except it works by parsing a file
     instead of a string.  See the documentation of ‘strread’ for
     details.

     In addition to the options supported by ‘strread’, this function
     supports two more:

        • "headerlines": The first VALUE number of lines of FILENAME are
          skipped.

        • "endofline": Specify a single character or "\r\n".  If no
          value is given, it will be inferred from the file.  If set to
          "" (empty string) EOLs are ignored as delimiters.

     The optional input N (format repeat count) specifies the number of
     times the format string is to be used or the number of lines to be
     read, whichever happens first while reading.  The former is
     equivalent to requesting that the data output vectors should be of
     length N.  Note that when reading files with format strings
     referring to multiple lines, N should rather be the number of lines
     to be read than the number of format string uses.

     If the format string is empty (not just omitted) and the file
     contains only numeric data (excluding headerlines), textread will
     return a rectangular matrix with the number of columns matching the
     number of numeric fields on the first data line of the file.  Empty
     fields are returned as zero values.

     Examples:

            Assume a data file like:
            1 a 2 b
            3 c 4 d
            5 e

            [a, b] = textread (f, "%f %s")
            returns two columns of data, one with doubles, the other a
            cellstr array:
            a = [1; 2; 3; 4; 5]
            b = {"a"; "b"; "c"; "d"; "e"}

            [a, b] = textread (f, "%f %s", 3)
            (read data into two culumns, try to use the format string
            three times)
            returns
            a = [1; 2; 3]
            b = {"a"; "b"; "c"}


            With a data file like:
            1
            a
            2
            b

            [a, b] = textread (f, "%f %s", 2)
            returns a = 1 and b = {"a"}; i.e., the format string is used
            only once because the format string refers to 2 lines of the
            data file.  To obtain 2x1 data output columns, specify N = 4
            (number of data lines containing all requested data) rather
            than 2.

     See also: Note: strread, Note: load, Note:
     dlmread, Note: fscanf, *note textscan:
     XREFtextscan.

 -- : C = textscan (FID, FORMAT)
 -- : C = textscan (FID, FORMAT, REPEAT)
 -- : C = textscan (FID, FORMAT, PARAM, VALUE, ...)
 -- : C = textscan (FID, FORMAT, REPEAT, PARAM, VALUE, ...)
 -- : C = textscan (STR, ...)
 -- : [C, POSITION, ERRMSG] = textscan (...)
     Read data from a text file or string.

     The string STR or file associated with FID is read from and parsed
     according to FORMAT.  The function is an extension of ‘strread’ and
     ‘textread’.  Differences include: the ability to read from either a
     file or a string, additional options, and additional format
     specifiers.

     The input is interpreted as a sequence of words, delimiters (such
     as whitespace), and literals.  The characters that form delimiters
     and whitespace are determined by the options.  The format consists
     of format specifiers interspersed between literals.  In the format,
     whitespace forms a delimiter between consecutive literals, but is
     otherwise ignored.

     The output C is a cell array where the number of columns is
     determined by the number of format specifiers.

     The first word of the input is matched to the first specifier of
     the format and placed in the first column of the output; the second
     is matched to the second specifier and placed in the second column
     and so forth.  If there are more words than specifiers then the
     process is repeated until all words have been processed or the
     limit imposed by REPEAT has been met (see below).

     The string FORMAT describes how the words in STR should be parsed.
     As in FSCANF, any (non-whitespace) text in the format that is not
     one of these specifiers is considered a literal.  If there is a
     literal between two format specifiers then that same literal must
     appear in the input stream between the matching words.

     The following specifiers are valid:

     ‘%f’
     ‘%f64’
     ‘%n’
          The word is parsed as a number and converted to double.

     ‘%f32’
          The word is parsed as a number and converted to single
          (float).

     ‘%d’
     ‘%d8’
     ‘%d16’
     ‘%d32’
     ‘%d64’
          The word is parsed as a number and converted to int8, int16,
          int32, or int64.  If no size is specified then int32 is used.

     ‘%u’
     ‘%u8’
     ‘%u16’
     ‘%u32’
     ‘%u64’
          The word is parsed as a number and converted to uint8, uint16,
          uint32, or uint64.  If no size is specified then uint32 is
          used.

     ‘%s’
          The word is parsed as a string ending at the last character
          before whitespace, an end-of-line, or a delimiter specified in
          the options.

     ‘%q’
          The word is parsed as a "quoted string".  If the first
          character of the string is a double quote (") then the string
          includes everything until a matching double quote—including
          whitespace, delimiters, and end-of-line characters.  If a pair
          of consecutive double quotes appears in the input, it is
          replaced in the output by a single double quote.  For
          examples, the input "He said ""Hello""" would return the value
          ’He said "Hello"’.

     ‘%c’
          The next character of the input is read.  This includes
          delimiters, whitespace, and end-of-line characters.

     ‘%[...]’
     ‘%[^...]’
          In the first form, the word consists of the longest run
          consisting of only characters between the brackets.  Ranges of
          characters can be specified by a hyphen; for example,
          %[0-9a-zA-Z] matches all alphanumeric characters (if the
          underlying character set is ASCII). Since MATLAB treats
          hyphens literally, this expansion only applies to alphanumeric
          characters.  To include ’-’ in the set, it should appear first
          or last in the brackets; to include ’]’, it should be the
          first character.  If the first character is ’^’ then the word
          consists of characters *not* listed.

     ‘%N...’
          For %s, %c %d, %f, %n, %u, an optional width can be specified
          as %Ns, etc.  where N is an integer > 1.  For %c, this causes
          exactly N characters to be read instead of a single character.
          For the other specifiers, it is an upper bound on the number
          of characters read; normal delimiters can cause fewer
          characters to be read.  For complex numbers, this limit
          applies to the real and imaginary components individually.
          For %f and %n, format specifiers like %N.Mf are allowed, where
          M is an upper bound on number of characters after the decimal
          point to be considered; subsequent digits are skipped.  For
          example, the specifier %8.2f would read 12.345e6 as 1.234e7.

     ‘%*...’
          The word specified by the remainder of the conversion
          specifier is skipped.

     ‘literals’
          In addition the format may contain literal character strings;
          these will be skipped during reading.  If the input string
          does not match this literal, the processing terminates.

     Parsed words corresponding to the first specifier are returned in
     the first output argument and likewise for the rest of the
     specifiers.

     By default, if there is only one input argument, FORMAT is "%f".
     This means that numbers are read from the input into a single
     column vector.  If FORMAT is explicitly empty ("") then textscan
     will return data in a number of columns matching the number of
     fields on the first data line of the input.  Either of these is
     suitable only when the input is exclusively numeric.

     For example, the string

          STR = "\
          Bunny Bugs   5.5\n\
          Duck Daffy  -7.5e-5\n\
          Penguin Tux   6"

     can be read using

          A = textscan (STR, "%s %s %f");

     The optional numeric argument REPEAT can be used for limiting the
     number of items read:

     -1
          Read all of the string or file until the end (default).

     N
          Read until the first of two conditions occurs: 1) the format
          has been processed N times, or 2) N lines of the input have
          been processed.  Zero (0) is an acceptable value for REPEAT.
          Currently, end-of-line characters inside %q, %c, and %[...]$
          conversions do not contribute to the line count.  This is
          incompatible with MATLAB and may change in future.

     The behavior of ‘textscan’ can be changed via property/value pairs.
     The following properties are recognized:

     "BufSize"
          This specifies the number of bytes to use for the internal
          buffer.  A modest speed improvement may be obtained by setting
          this to a large value when reading a large file, especially if
          the input contains long strings.  The default is 4096, or a
          value dependent on N if that is specified.

     "CollectOutput"
          A value of 1 or true instructs ‘textscan’ to concatenate
          consecutive columns of the same class in the output cell
          array.  A value of 0 or false (default) leaves output in
          distinct columns.

     "CommentStyle"
          Specify parts of the input which are considered comments and
          will be skipped.  VALUE is the comment style and can be either
          (1) A string or 1x1 cell string, to skip everything to the
          right of it; (2) A cell array of two strings, to skip
          everything between the first and second strings.  Comments are
          only parsed where whitespace is accepted and do not act as
          delimiters.

     "Delimiter"
          If VALUE is a string, any character in VALUE will be used to
          split the input into words.  If VALUE is a cell array of
          strings, any string in the array will be used to split the
          input into words.  (default value = any whitespace.)

     "EmptyValue"
          Value to return for empty numeric values in non-whitespace
          delimited data.  The default is NaN.  When the data type does
          not support NaN (int32 for example), then the default is zero.

     "EndOfLine"
          VALUE can be either an emtpy or one character specifying the
          end-of-line character, or the pair "\r\n" (CRLF). In the
          latter case, any of "\r", "\n" or "\r\n" is counted as a
          (single) newline.  If no value is given, "\r\n" is used.

     "HeaderLines"
          The first VALUE number of lines of FID are skipped.  Note that
          this does not refer to the first non-comment lines, but the
          first lines of any type.

     "MultipleDelimsAsOne"
          If VALUE is nonzero, treat a series of consecutive delimiters,
          without whitespace in between, as a single delimiter.
          Consecutive delimiter series need not be vertically aligned.
          Without this option, a single delimiter before the end of the
          line does not cause the line to be considered to end with an
          empty value, but a single delimiter at the start of a line
          causes the line to be considered to start with an empty value.

     "TreatAsEmpty"
          Treat single occurrences (surrounded by delimiters or
          whitespace) of the string(s) in VALUE as missing values.

     "ReturnOnError"
          If set to numerical 1 or true, return normally as soon as an
          error is encountered, such as trying to read a string using
          ‘%f’.  If set to 0 or false, return an error and no data.

     "Whitespace"
          Any character in VALUE will be interpreted as whitespace and
          trimmed; The default value for whitespace is " \b\r\n\t" (note
          the space).  Unless whitespace is set to "" (empty) AND at
          least one "%s" format conversion specifier is supplied, a
          space is always part of whitespace.

     When the number of words in STR or FID doesn’t match an exact
     multiple of the number of format conversion specifiers,
     ‘textscan’’s behavior depends on whether the last character of the
     string or file is an end-of-line as specified by the ‘EndOfLine’
     option:

     last character = end-of-line
          Data columns are padded with empty fields, NaN or 0 (for
          integer fields) so that all columns have equal length

     last character is not end-of-line
          Data columns are not padded; ‘textscan’ returns columns of
          unequal length

     The second output POSITION provides the location, in characters
     from the beginning of the file or string, where processing stopped.

     See also: Note: dlmread, Note: fscanf,
     Note: load, Note: strread, *note textread:
     XREFtextread.

   The ‘importdata’ function has the ability to work with a wide variety
of data.

 -- : A = importdata (FNAME)
 -- : A = importdata (FNAME, DELIMITER)
 -- : A = importdata (FNAME, DELIMITER, HEADER_ROWS)
 -- : [A, DELIMITER] = importdata (...)
 -- : [A, DELIMITER, HEADER_ROWS] = importdata (...)
     Import data from the file FNAME.

     Input parameters:

        • FNAME The name of the file containing data.

        • DELIMITER The character separating columns of data.  Use ‘\t’
          for tab.  (Only valid for ASCII files)

        • HEADER_ROWS The number of header rows before the data begins.
          (Only valid for ASCII files)

     Different file types are supported:

        • ASCII table

          Import ASCII table using the specified number of header rows
          and the specified delimiter.

        • Image file

        • MATLAB file

        • Spreadsheet files (depending on external software)

        • WAV file

     See also: Note: textscan, Note: dlmread,
     Note: csvread, Note: load.

Saving Data on Unexpected Exits

automatically generated by info2www version 1.2.2.9