Extract values vs export data from scouts time series

Hi Francois,

I noticed that if I export data to Matlab in two different ways, I get different results. If I follow:
Process > process sources > extract value (for a scout)
and export this variable to Matlab, it is not the same as
Process > process sources > scout time series > right-click time series and export to Matlab.
The file structure is slightly different; the former gives me a Values variable, and in the latter there's an F variable containing a single cell containing the data. I've plotted both series on top of each other here so you can see the difference. The plots are of the rms of the extracted signals. I also plotted the means separately and saw similar small differences.

Are these processes supposed to be different? The difference seems to be very small.



Hi Sarah,

“Extract scouts time series” is much older and does only the extraction of scouts the time series. It has more options though.
“Extract values” is a newer and more versatile process, that can extract/concatenate all sorts of inputs. However it does not include all the options, only the default options are available for the scout computation.
They rely on the same functions, so they should produce the same results. However you need to make sure you use exactly the same options for both.

Both processes should produce files of the type “matrix”, with a field “Value”. I’m not sure I understand how you generated this file with the field “F”, this is what you would get if you used this “Extract values” process on either recordings or “matrix” files with the option “Average selected signals” selected.
Make sure you start from the same source files for both extract versions (you cannot execute the two processes at once, otherwise the input of the 2nd process would be the output of the first one - that would explain the type of data you get…)

There are so many possible combinations of options for these processes, maybe there are configurations I didn’t think of. If you need more explanations, please include screen captures to illustrate your database configuration and process options.