Averaging data to a time base

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Hello. I am new to igor and i am having trouble trying to do the following using the help menus.

I will try to explain my problem as best as i can.

I have a high frequency data column (y) and a time stamp associated with this column (x). The frequency of the data is 6 minutes. What i want to do is to create a new wave with hourly timestamps and average the high frequency data (y) to these new time stamps specifying the range.

eg. If i have a timestamp of 12/03/2009 01:00, then i want to average the high frequency data +/- 30 minutes of the low frequency time stamp and create a new wave.

Cheers
We call that "decimation". Add this line:

#include <Decimation>

to your Procedure window, then close the Procedure window. It will load in a WaveMetrics procedure file that will do the decimation for you. If you the go to the Analysis menu you will find a new item, "Decimate".

You will have to decimate the Y wave and the time wave separately. Be careful that you use the same settings for both.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

March 19, 2009 at 05:48 pm - Permalink
Many thanks for your help.

I was wondering if it is also possible to output the standard deviation instead of the average using this technique.

Cheers

March 20, 2009 at 05:53 am - Permalink
[quote=gfors]I was wondering if it is also possible to output the standard deviation instead of the average using this technique.[/quote]

It looks like you can generate std dev in addition to average. When I #include the decimation procedure file and choose Analysis->Decimation, I see a "Generate a Standard Deviation Wave" popup menu at the bottom of the dialog.

March 20, 2009 at 11:18 pm - Permalink