commons-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
Subject [math] Getting second derivative for discrete dataset
Date Fri, 30 Mar 2012 20:49:51 GMT

I have a (newbie) question about how to go about solving the problem below with commons-math.

1) I have histogram data (equal x intervals) based off some distribution.
2) I need a way to calculate the second differential between two given x points in the distribution.

Here is what I think I should do:
1) Feed the (x,y) values represented by the top of each histogram entry within my x-range
into a UnivariateRealInterpolator between ranges (x1,y1) and (x2,y2).
2) The interpolate method gives me back a PolynomialSplineFunction (call if psf).
3) I get the second differential UnivariateRealFunction (call it urf) by calling psf.getPolynomialSplineDerivative().derivative()
4) I compute the second derivative value as the difference of urf.value(x2) - urf.value(x1)

Does this sound like a reasonable/accurate approach? Any suggestions/gotchas or pointers to
better approaches?

Thanks very much,


To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message