MATLAB编码器支持的csvread函数

Question

I have a MATLAB script that contains a csvread call to read in data from a csv file. Now I'm trying to compile my MATLAB script into C using MATLAB Coder. However, csvread is not a member of the supported functions for C code generation.

The only read from file function I found is fread which only reads in binary file. Is there a way to use fread to read a csv file or is there any way around this?

Sample MATLAB script:

data = csvread('data.csv');

Sample csv file:

1
2
3
4

Answer 1

Sure, you can read in a .csv file with fread , you'll just need to process it yourself. Let's say you have myfile.csv , containing the text 1, 2, 3, 4 .

>> fid = fopen('myfile.csv','r');
>> a = fread(fid, 'char')'
a =
    49    44    32    50    44    32    51    44    32    52    13    10
>> b = char(a)
b =
1, 2, 3, 4
>> fclose(fid);

All those commands are supported by MATLAB Coder. b is now a string containing the text 1, 2, 3, 4 .

You'll now need to process that string to extract the numbers from between the commas. That's the portion of csvread that isn't supported by MATLAB Coder, as within csvread it uses regular expressions, which aren't supported by MATLAB Coder.

However, you'll probably find it easier than you might think, as the regular expressions within csvread have to cover the general case for any .csv file (which might include text fields as well as numbers, and fields that are quoted and can have commas within the quotes, and maybe even Unicode text as well). If you just have numbers, commas, and spaces, shouldn't be too hard - just iterate through the text character-by-character, stop each time you find a comma, and call str2double on the portion so far.