How to import large data file in function in matlab?

I have a satellite data values stored in a .dat file of almost 900 MB. The data is in the form of int8. I want to read as much data as possible from the start and then pass it in a function argument and then save the new signal in a separate file. I have used importdata but it cant work and unable to read large data file. Is there any other way which I can use to read data in chunks and put them together afterwards? Anyone please help me out. Its very important that I read this data.

The specifications of software, platform & PC are:

Matlab R2015a. Windows 7 64-bit, Core i5 1st Gen., 4 GB RAM, 250 of hard Disk Space

[Bob Thompson]

Is it possible to break apart the file manually, and read the different sections?

[Sheikh Alsheikh]

actually I have no knowledge about number of rows and column of data or synchronization, i am unable to break or even process my file whenever i give any command it turn into long lasting processing so i have to terminate

[Bob Thompson]

Does Matlab give you a memory error? Or does it just take forever to load? 900MB is a pretty big file, so it will take Matlab a while to process it (probably several minutes).

An alternative option would be to open the file in a text editor (Textpad, Wordpad, etc.), and try to break the file apart that way.

[dpb]

See

doc fread

and the sections on large files...

Large-files-and-big-data

[Sheikh Alsheikh]

Dear Bob When i used the Matlab Build in import data button an upload file in it , it show me whole file in three different variable in form just like excel format

[Sheikh Alsheikh]

Thanx , dpd but i have to upload y file in a function argument

[Guillaume]

The data is in the form of int8

What does that mean? Is the file a text file (as Bob assumed) or a binary file. Loading a 900MB binary file shouldn't take long.

[dpb]

"have to upload y file in a function argument"

And what does that mean?

You have a large file; TMW supplies several tools to deal with those but to give any specific help we need at least a klew as to what it is that is the real problem, also specifically.

Answer 1

[Karan Singh]

Hi @Sheikh Alsheikh,

I think I have the perfect solution for you! You can check out this MathWorks documentation ( https://in.mathworks.com/help/matlab/large-files-and-big-data.html ), as it provides relevant details. I believe "Datastore" would be the best approach for your needs. https://in.mathworks.com/help/matlab/datastore.html

Karan