Opening a large file for FFT

File I/O & Databases

Opening a large file for FFT

Postby magreent on 21 May 2008, 20:18

I acquired data overnight and now I have a 400MB file. I need to do an FFT on the data but now I have memory problems and cannot open the data. The error I get in Labview is: Not enough memory to complete this operation. Is there any way around this?

Thanks.
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Re: Opening a large file for FFT

Postby Eugen Graf on 23 May 2008, 14:21

If you have problems with a large file, so you can read only a piece of this file and make your calculations with this. Than read the next piece and so on.

To make a FFT over the whole big dataset you should first average this data. E.g. take 100 first values average them to one value. So you will get from 400 mb file only 400/100 mb file and probably will be able to make FFT over this data.

Else you can make FFTs piece for piece.

The problem with memory is not the LabVIEW issue, much mote the issue of your PC RAM.
And try to make so less copies (every wire branch is a copy) of big data sets in your block diagramm.
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