CSVREAD Read Comma Separated Value (CSV) File

Section: Input/Ouput Functions

Usage

The csvread 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 csvread is 
   x = csvread('filename')

which attempts to read the entire CSV file into array x. 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 csvread allows you to specify the first row and column (zero-based index) 

  x = csvread('filename',firstrow,firstcol)

The last form allows you to specify the range to read also. This form is 

  x = csvread('filename',firstrow,firstcol,readrange)

where readrange is either a 4-vector of the form [R1,C1,R2,C2], where R1,C1 is the first row and column to use, and R2,C2 is the last row and column to use. You can also specify the readrange as a spreadsheet range B12..C34, in which case the index for the range is 1-based (as in a typical spreadsheet), so that A1 is the first cell in the upper left corner. Note also that csvread is somewhat limited.

Example

Here is an example of a CSV file that we wish to read in 

     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

We start by reading the entire file 

--> 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

Next, we read everything starting with the second row, and third column 

--> csvread('sample_data.csv',1,2)

ans = 
 52 93  5  6 
  4  4 90 -3 
 13 67 30 43 
 14 44  1  0

Finally, we specify that we only want the 3 x 3 submatrix starting with the second row, and third column 

--> csvread('sample_data.csv',1,2,[1,2,3,4])

ans = 
 52 93  5 
  4  4 90 
 13 67 30