How to get frequency spectrum from spectrogram?

[Ramon Campos]

Hello,

i'm trying to implement some wavelet frequency analysis in SEMG signal.

i've got a scalogram (X- time, Y- scale, Z-energy) and a spectrogram (X- time, Y-frequency, Z-amplitude), as can be seen in the picture attached (middle graph).

How can I "rotate" axis of the graphic, or extract the frequency spectrum to get (Y-amplitue, X- frequency) graph ?

Or yet, how to get the values of X, Y and Z axis into arrays to build a new graphic ?

I've tried to use some property node, but no success.

Hope someone could help!

Ramon Campos

[Ramon Campos]

Where are the "masters of labivew" to help me??

[SunshineDesign]

Ramon you did not include any code to review. I suspect you have a 3 dimensional array of the data. This data will be either in full array format or the waveform format (i.e. T0 dT or F0 dF)

for the respective time or frequency oriented data axis. No matter the data from it can be transformed or conformally mapped to a different orientation by swapping the arrays in the dimensions. The arrays can be parsed by dimension and reassembled the way you want prior to sending to the graphic tool.

[Abel_Souza]

Hi Ramon,

  May you poste your code or an imagem from your block diagram for I understand what you can change in your code.

Best Regards,

Abel Souza

Applications Engineering

NI Brazil

[Ramon Campos]

Hello SunshineDesign and Abel.

thank yours for the attention.

after "fighting" against the program, I guess I did it.

In fact, the spectrogram is a 2D array....

I used the YScale.Offset&Mult from spectrogam graph and connected it to XScale.Offset&Mult from frequecy spectrum graph.....

It get strange when use low scales (4, 8, 16)

Here are the VI (lv 2010) and an EMG signal from biceps brachii in a 30 seconds isometric contraction.

Can you validate my implementation?

Thanks Sunshine!

Obrigado Abel!

PS.

Hey! I can not attach a LVM file???

change the extension from .TXT to .LVM

Ramon Campos

[SunshineDesign]

You are welcome. A Kudo would be appreciated.

[Ramon Campos]

... some help would be appreciated too!