1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>CSVREAD Read Comma Separated Value (CSV) File
</TITLE>
</HEAD>
<BODY>
<H2>CSVREAD Read Comma Separated Value (CSV) File
</H2>
<P>
Section: <A HREF=sec_io.html> Input/Ouput Functions </A>
<H3>Usage</H3>
The <code>csvread</code> function reads a text file containing comma
separated values (CSV), and returns the resulting numeric
matrix (2D). The function supports multiple syntaxes. The
first syntax for <code>csvread</code> is
<PRE>
x = csvread('filename')
</PRE>
<P>
which attempts to read the entire CSV file into array <code>x</code>.
The file can contain only numeric values. Each entry in the
file should be separated from other entries by a comma. However,
FreeMat will attempt to make sense of the entries if the comma
is missing (e.g., a space separated file will also parse correctly).
For complex values, you must be careful with the spaces). The second
form of <code>csvread</code> allows you to specify the first row and column
(zero-based index)
<PRE>
x = csvread('filename',firstrow,firstcol)
</PRE>
<P>
The last form allows you to specify the range to read also. This form
is
<PRE>
x = csvread('filename',firstrow,firstcol,readrange)
</PRE>
<P>
where <code>readrange</code> is either a 4-vector of the form <code>[R1,C1,R2,C2]</code>,
where <code>R1,C1</code> is the first row and column to use, and <code>R2,C2</code> is the
last row and column to use. You can also specify the <code>readrange</code> as
a spreadsheet range <code>B12..C34</code>, in which case the index for the
range is 1-based (as in a typical spreadsheet), so that <code>A1</code> is the
first cell in the upper left corner. Note also that <code>csvread</code> is
somewhat limited.
<H3>Example</H3>
Here is an example of a CSV file that we wish to read in
<P>
<PRE>
sample_data.csv
10, 12, 13, 00, 45, 16
09, 11, 52, 93, 05, 06
01, 03, 04, 04, 90, -3
14, 17, 13, 67, 30, 43
21, 33, 14, 44, 01, 00
</PRE>
<P>
We start by reading the entire file
<PRE>
--> csvread('sample_data.csv')
ans =
10 12 13 0 45 16
9 11 52 93 5 6
1 3 4 4 90 -3
14 17 13 67 30 43
21 33 14 44 1 0
</PRE>
<P>
Next, we read everything starting with the second row, and third column
<PRE>
--> csvread('sample_data.csv',1,2)
ans =
52 93 5 6
4 4 90 -3
13 67 30 43
14 44 1 0
</PRE>
<P>
Finally, we specify that we only want the <code>3 x 3</code> submatrix starting
with the second row, and third column
<PRE>
--> csvread('sample_data.csv',1,2,[1,2,3,4])
ans =
52 93 5
4 4 90
13 67 30
</PRE>
<P>
</BODY>
</HTML>
|
