Convert amplitude vs time graph to energy vs time graph

[samitha95]

Hi,

I would like to convert amplitude vs time graph into energy vs time graph. How can I do it?

Also want to indicate the time value of 40% of maximum amplitude.

Relevant VI and data file are attached below.

Please help.

[altenbach]

We don't know how to convert amplitude into Energy. Do you have a calibration formula? Just apply it before graphing!

If you just want to change the axis label, you can do it in edit mode directly or change it via a property node.

You could place a cursor at 40% of the max amplitude once you decide where (max absolute amplitude, max positive amplitude, abs(max negative amplitude), etc.). Do you need help with that?

[altenbach · Accepted solution]

Maybe something like this (assuming the Y values are already calibrated)?

(And please don't maximize the front panel to the screen!)

[samitha95]

Thanks @altenbach for your explanation.

The energy transported by a wave is directly proportional to the square of the amplitude of the wave. So it has to square the amplitude values to get the relevant energy values. When doing that do it need to put amplitude values to an array before the conversion? or can I directly square the values taken by graph?

[altenbach · Accepted solution]

You can just insert a square function into the array of amplitudes right after you index out the columns.

(A graph is an indicator, so operate on the data before it gets there.)

[samitha95]

Thanks @altenbach, I'll do like that.

Could you please explain the use of below functions I attached in the photo?

[altenbach]

It is a property node of the graph.