Best way to acess external config data (load mat file vs import data vs fscanf etc. )

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Mathieu on 13 Jun 2014
Answered: Pritesh Shah on 17 Jun 2014
Greetings, I need to store some external parameters in a configuration file (not more than 50 lines). It is not yet defined how many subfunction will need to have access to it but the overall speed will be important. The whole application will be compiled in the end.
I found multiple ways to do this but I am not sure what is the best way: I could load a mat file, read an ascii txt file, a csv and so on (and all this with multiple possibilities).
What is the best (most efficient) way to do this ?
dpb on 17 Jun 2014
The biggest difference in speed between the classes is whether they're formatted or unformatted files. The overhead for formatted files is first there's many more bytes/numeric value and secondly it takes compute-time to do the conversion from/to internal storage to the ASCII representation.
For formatted files the higher-level, more convenient forms TMW supplies have all the extra processing and logic built into them that make them more convenient to use but that also comes at a price of far more complexity in the processing. load is slightly more complex than a pure stream of bytes owing to the fact it also saves the structure and the information associated with the variable(s) whereas all of that is your responsibility if you simply write an array as the byte stream.
Similarly, if use fscanf by itself, all the formatting and structure in the file is written explicitly so there's no additional internal logic. If you use one of the more convenient forms then they eventually get down to the final call to the i/o but they have (a varying amount of) flexibility built in so again, that costs something in performance in payback for the convenience (there is no free lunch).
OTOH, for the size of the data you're talking about, I'll reemphasize that write the code for ease of maintainability and clarity of expression first; the amount of data you're talking about is so minimal as to be of no concern for execution time or storage space (again, presuming the avoidance of doing the same thing over and over and over...).

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Accepted Answer

Mathieu on 17 Jun 2014
The following comment pretty much answers my question:

More Answers (1)

Pritesh Shah
Pritesh Shah on 17 Jun 2014
I think, You may try tic and toc command to find out optimal solution for your case.

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