Re : wavelet diadem

[kkloo]

Hello,

I want to know if it's possible to do wavelet transform in DIAdem?

Thanks for your answers

Best regards

Pascal

[R_Duval]

Hi Pascal,

Do you want only use DIAdem?

With LabVIEW there is the Advanced Signal Processing Toolkit for the wavelet transform.

Maybe you could create a DLL that implements portions of the Advanced Signal Processing Toolkit and use it on DIAdem.

I will try to find if there is a way to do wavelet transform in DIAdem.

Regards,

[kkloo]

Bonjour Romain,

Je suis français, donc je pense que ce sera plus facile de s'exprimer.

Tout d'abord merci pour votre réponse.

En fait je n'utilise que DIAdem, que j'ai découvert il y a quelques semaines. Pour nos acquisitions nous utilisons Labview, le soucis est que je ne maîtrise pas cet outil.

Ensuite je fait du post traitement. Ce sont des acquisitions vibratoires que je dépouille.

J'aimerais utiliser l'analyse par transformée en ondelette pour avoir d'autres outils de traitement et d'expertises.

J'aimerais bien utiliser NI Sound & Vibration, mais je n'arrive pas à lire mes fichiers TDM issue de DIAdem (acquisitions de 500 000 points)

Car trop gros.

Je ne peux pas non plus changer la fréquence d'acquisition, car tout est bridé.

L'utilisation d'un logiciel comme NI Sound & Vibration, me permettrait d'utiliser des outils plus spécifique. Car pour l'instant j'essaie de les créer sous DIAdem (Spectre 1/n d'octave, Transformée en ondelette,...)

Si vous avez un moyen pour lire ces acquisitions sous NI Sound & Vibration, ce serait un grand pas!!!

Merci d'avance pour toutes aides apportées.

Cordialement

Pascal

[Brad_Turpin]

Hi Pascal,

My French is a bit rusty, so forgive me if I misunderstood parts of your most recent post.  It sounds like you are acquiring large (500 000 point) vibration data files using LabVIEW, and either they're TDM files to start with or they're TDM files after DIAdem gets done with them.  It also sounds like you would be happy to use the LabVIEW Sound and Vibration Toolkit for the wavelet analysis if you could just  load the TDM data into the LV-SVT data clusters.  It looks like you're saying the main trouble there is the large TDM file size.  I understand that it is not feasible to reduce the file size by reducing the acquisition rate.

You can use the LabVIEW Storage VIs to load either the full TDM file, all of the values of some of the channels, or some of the values of the channels in the TDM file.  So you really have quite a few TDM file loading options.  How many channels are in your TDM file, and how many of those do you need for the wavelet analysis?  Is the wavelet analysis something that can be carried out piece-wise?  You could load the first 25% of the channels and do the wavelet analysis on that first chunk of data and then repeat the calculation 3 more times, for instance (if piece-wise calculation works with the wavelet analysis).

If need be, it's actually quite easy to call LabVIEW VIs from DIAdem using the LVRuntime object in a VBScript.  I don't think there are any built-in wavelet analysis options in DIAdem, but I am checking with R&D on that for possible options.

Brad Turpin

DIAdem Product Support Engineer
National Instruments