Find xMax and delta x from scaled Ydata.

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Mon, 09/14/2015 - 09:42 am

Hi All,

I have a set of waves Ydata which has x-scaling such that when I plot XvsY (Ydata=wave Xdata=calculated) everything is correct.
Is there a way to recover minValue, maxValue and delta of the xscaling from the Ydata?

I would like to shift the Ydata along the xaxis and I was trying to use the SetScale function as follows but then realised I didn't now how to call up the start or the delta of a pre-scaled wave.

SetScale/P x (start+A),delta,"", wavename


I killed my x-waves as part of my load procedure to avoid cluttering but now I feel I may have to bring them back. Is there a way to at least find the minimum point and the delta from scaled Ydata?

I think I can use Wavestats to find the V_minloc which i think will give me the first point (My graphs are gaussian fits of data sets) but to find the delta I have no idea.

To clarify:
If i have a graph Y=X.
I want to take the Y data and change the scaling for example shift 2 units and give the resultant graph Y=X-2.
Can anyone help me?

Thanks,
N
The function leftx() will give you the X value corresponding to point zero.
The function rightx() will give you the X value corresonding to the point numpnts(wave), a non-existent point. It is conceptually the right edge of the X range of the last point.
You can get the X value of the true last point using pnt2x(wave, numpnts(wave)-1) or with leftx(wave)+(numpnts(wave)-1)*deltax(wave).

These are old functions that apply only to 1D waves. If you need similar information for waves with more than one dimension, use DimDelta(), DimOffset(), and DimSize().

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

September 14, 2015 at 09:52 am - Permalink

Hi John,
Thanks for the speedy reply!

This looks like it will do the trick! =)

Thanks again,
N

September 14, 2015 at 09:59 am - Permalink