Please update h file in DWdatareader (DLL for Matlab)

Hi,

I noticed that some functions in de DWdatareader DLL are not placed in the function definition in the DWDataReaderLib.h file (Matlab files in the datareader package).

One example is the function "DWGetChannelFactors". It was missing in the h file and I had to add it myself.

Can you please add this (and possible other missing functions) to the h file definition, so that in the future, all functions are in the h-file.

Thanks,

Harm

By the way, the function "DWGetChannelFactors" leads to a wrong answer when opening a file made in Dewesoft 7.1.2.
Files from Dewesoft X1 looks okay.
Is this indeed a version issue?

Hi,

our developers have updated the header file, so you should now be able to use all of the functions. We will also take a look at the "DWGetChannelFactors" function to make sure it outputs the correct results, and write you back as soon as we figure something out.

Hi,

the function "DWGetChannelFactors" outputs two parameters: the scale and the offset. If you compare these values to the ones that you're able to see in DEWESoft (under channel properties or the setup tab in analysis mode), they won't match. The reason for this is the existence of two pairs of scale and offset values.

The values that are returned when calling the "DWGetChannelFactors" function are raw values, which are formed when reading the data straight from the DAQ card. The scale and offset values that you're able to see in DEWESoft on the other hand represent the factors of the already transformed/scaled data. That is the reason that the scale and offset will be 1 and 0, for any channels without a sensor association.

That being said, the output values that you're reading in MATLAB are not wrong, they're just of a different type. Currently, there is now way of accessing the scaled channel factors, but we could potentially add it if that is something that you require in your analysis. We also have functions that differentiate between reading the raw (DWGetRawSamples) and scaled (DWGetScaledSamples) data.

Hi,

thanks for your (much appreciated) reply. I look forward to the update h-file.

Concerning the scaling, it is good thing to know in your data when values are scaled or not, without checking the setup file.
However, I was not aware of the GetRawSamples function. That would also solve the problem, since you can compare the scaled and raw samples.

Best regards,

Harm