How to change column (wave) data value for a certian range (row index)

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Wed, 01/25/2012 - 09:04 am

How can I change column data value ( wave value ) for a certain wave say wave 0 but for certain range of rows.
If the waves ( say wave0 and wave1) has 100 data row(index) each ...

a) I like to subtract 5 from each data points of wave 0 from row index 4 to 40
b) Also I like to subtract (wave0- wave1) for the range 4 to 40 (row index)
c) Is there any GUi available to do this ?
You need to read about wave assignments. Please copy this command, paste it into Igor's command line, and press Enter:

DisplayHelpTopic "Waveform Arithmetic and Assignment"
Quote:
a) I like to subtract 5 from each data points of wave 0 from row index 4 to 40

Is there really a space in the name "wave 0"? That complicates typing... I will assume there is...

'wave 0'[4,40] -= 5
Quote:
b) Also I like to subtract (wave0- wave1) for the range 4 to 40 (row index)

Now there is no space. You need to be careful of that. "wave 0" and "wave0" are two different names. The presence of a space in the name requires the use of the single quotes around the name, so you're better off not having the space.

wave0[4,40] -= wave1
Quote:
c) Is there any GUi available to do this ?

You might look at Analysis->Compose Expression, but it doesn't support the subrange syntax on the left hand side of the assignment. I think most people find it's easier just to type the assignments on the command line.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

January 25, 2012 at 09:18 am - Permalink

Thank you so much...It did work..The wave name is wave0 ..without any space. Indeed typing by hand is easier than composite expression gui. Although I think if there woule have been a simple GUI that can be invoked by selecting a column (by mouse) and then clicking "column math" and it will give just option like "row Range" "value" and can parse expression typed like "wave0=wave0+5" that would be nice.
Athanks again

January 25, 2012 at 09:35 am - Permalink