====== acsvread ======
===== Motivation =====
Very frequently data analysis is performed using several different programs at a time (e.g. Excel for text file pre-processing, Matlab for fMRI data analysis and R/SAS/SPSS for specific group statistic models), which leads to the question of how to best transfer data between programs. ''acsvread'' is one way to read in an Excel sheet that was saved as a CSV (comma-separated-values) file into a Matlab cell or struct array.
===== Requirements =====
You should have the data you wish to read in prepared in one common format (that is, make sure to use the same delimiter, etc., when you save the files as CSV).
===== Function reference ('help acsvread') =====
acsvread - reads a text based (non-numeric) csv file
due to the different approaches when reading csv files, both a cell
and a struct oriented method can be used.
FORMAT: table = acsvread(file, [delimiter,] options)
Input fields:
file either filename (preferably absolute) to input or
a newline seperated string containing a table or
even a cell array with input lines to process
delimiter delimiter character(s) (used for MATLAB's strtok)
options struct array with multiple of the following options
.asmatrix table array is a MxN cell array, not 1xM of 1xN
.convert if given, try to convert numerical values to such;
plus if set to 'deblank', deblanks all fields
.headline if given, functions assumes named fields (heads);
this results in a struct array, not a cell array!
further, if headline is empty read headline from
given input, otherwise use this at headline!
.multidelim if given, treat delimiter as multiple tokens
.numonly if given, only reads numbers
.range if given, acsvread only reads within range can be
either [upper-left-x,y, lower-right-x,y] coordinates
or a string in MS-Excel notation ('A4:F9') where
any missing coordinate is stretched to the edge
.readstart if given, start reading at line after given token
.readstop if given, stop reading at line before given token
meaning: lines must contain this token to match
.replacef cell array with "replace from" strings
.replacet cell array with "replace to" string
See also asciiread, splittocell.
===== Options =====
==== asmatrix ====
If not given or set to ''1'', the function will create a nested cell array of cell arrays. If set to ''1'', the output will be a Rows-by-Columns cell array.
==== convert ====
This flag controls whether or not ''acsvread'' attempts to convert numeric values (and whether or not deblanking of strings occurs).
==== headline ====
This option can either be set to a string that, when split with the delimiter, contains the field names of the table to read. Or if the file itself contains that information, you can set ''.headline'' to '''''', which then attempts to read the headers from the first row in the selected range.
==== multidelim ====
Flag whether or not to concatenate multiple consecutive delimiters into one (only useful for very special cases).
==== numonly ====
Flag whether non-numeric data should be discarded.
==== range ====
By default, ''acsvread'' will attempt to read the entire file, but sometimes you want to discard part of the information right away (e.g. the first two columns). In that case, you can set the ''.range'' option to a Microsoft Excel compatible Range descriptor (e.g. '''C1:Z1000''').
==== readstart / readstop ====
These two optional settings are useful if the content to read is embedded in information that is of variable length but contains a specific keyword/token to identify the line from where to begin reading, e.g. by setting ''.readstart'' to '''Logfilename''', any lines before and including the line containing this keyword are discarded.
==== replacef / replacet ====
Sometimes you want to perform a "Search-and-Replace" before (or while) data is being read. You can pass two cell arrays which will then, in turn, be passed to ''strrep''.
===== Exemplary calls =====
* to read in a file which was saved with '','' (comma) as field separator, you could use: table = acsvread('tabularfile.csv', struct( ...
'asmatrix', 1, ...
'convert', 1));
* in case this file also has header fields (names in the first row) and you wish to convert the read file into a NrOfRows-by-1 struct, use: tstruct = acsvread('tabularfile.csv', struct( ...
'asmatrix', 1, ...
'convert', 1, ...
'headline', ''));