Averaging data to a time base
| gfors | March 18, 2009 - 11:47 | ||
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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 |
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Joined: 2007-06-29
Location: United States
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
Joined: 2009-03-18
Location: United Kingdom
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
Joined: 2007-06-21
Location: United States
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.