octave: Simple File I/O
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 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, fields F1 F2
... of the scalar structure STRUCT are saved as if they were
variables with corresponding names. 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 single matrix in a text file without header or any
other information.
‘-binary’
Save the data in Octave’s binary data format.
‘-float-binary’
Save the data in Octave’s binary data format but only using
single precision. Only use this format 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 only using single precision.
Only use this format 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
equally on files that are compressed with gzip outside of
octave, and gzip can equally 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.
DONTPRINTYET See also: 
load XREFload, *notesave_default_options:
DONTPRINTYET DONTPRINTYET See also: load XREFload, save_default_options
XREFsave_default_options, *notesave_header_format_string:
DONTPRINTYET DONTPRINTYET DONTPRINTYET See also: load XREFload, save_default_options
XREFsave_default_options, save_header_format_string
XREFsave_header_format_string, dlmread XREFdlmread, *noteDONTPRINTYET DONTPRINTYET DONTPRINTYET See also: load XREFload, save_default_options
XREFsave_default_options, save_header_format_string
XREFsave_header_format_string, dlmread XREFdlmread,
csvread XREFcsvread, fread XREFfread.
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.
Typical values include "-ascii", "-text -zip". The default value
is ‘-text’.
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: save XREFsave.
-- : 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.
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.
-- : 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 should 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: strftime XREFstrftime, save XREFsave.
-- : 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.
DONTPRINTYET See also: save XREFsave, dlmwrite XREFdlmwrite, *noteDONTPRINTYET See also: save XREFsave, dlmwrite XREFdlmwrite,
csvwrite XREFcsvwrite, fwrite XREFfwrite.
-- : STR = fileread (FILENAME)
Read the contents of FILENAME and return it as a string.
See also: fread XREFfread, textread XREFtextread,
sscanf XREFsscanf.
-- : 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);
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: disp XREFdisp.
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: dlmread XREFdlmread, csvread XREFcsvread,
csvwrite XREFcsvwrite.
-- : 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: csvread XREFcsvread, textscan XREFtextscan,
textread XREFtextread, dlmwrite XREFdlmwrite.
-- : 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’ (
dlmwrite XREFdlmwrite.).
See also: csvread XREFcsvread, dlmwrite XREFdlmwrite,
dlmread XREFdlmread.
-- : 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’ (
dlmread XREFdlmread.).
See also: dlmread XREFdlmread, textread XREFtextread,
DONTPRINTYET textscan XREFtextscan, csvwrite XREFcsvwrite, *noteDONTPRINTYET textscan XREFtextscan, csvwrite XREFcsvwrite,
dlmwrite XREFdlmwrite.
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.
DONTPRINTYET See also: strread XREFstrread, load XREFload, *noteDONTPRINTYET DONTPRINTYET See also: strread XREFstrread, load XREFload,
dlmread XREFdlmread, fscanf XREFfscanf, *notetextscan:
DONTPRINTYET DONTPRINTYET See also: strread XREFstrread, load XREFload,
dlmread XREFdlmread, fscanf XREFfscanf, 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: dlmread XREFdlmread, fscanf XREFfscanf,
DONTPRINTYET load XREFload, strread XREFstrread, *notetextread:
DONTPRINTYET load XREFload, strread XREFstrread, 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: textscan XREFtextscan, dlmread XREFdlmread,
csvread XREFcsvread, load XREFload.
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octave: Terminal Input
octave: Basic Input and Output