curve fitting - growth modelling
Posted 11 January 2012 - 08:05 AM
I'm just wondering, has any of you done any statistical modeling of plant growth? I know, plants normally have a s-shape growth pattern, but under certain conditions (e.g. disease, drought) they don't follow this kind of growth curves.
My data shows more of a parabolic curve, does any of you have idea how to fit a parabolic equation to describe that curve? Thanks in advance.
Posted 11 January 2012 - 02:43 PM
If you have prism graph or some other program (even excel) I can help more.
Posted 12 January 2012 - 04:05 AM
indeed my growth curves look like a u shape. mathematically I find it quite interesting. I'm just trying to sort out the way to explain this process in a biological context
thanks for your input. cheers.
Posted 12 January 2012 - 04:26 AM
Equation: Peak, Gaussian, 3 Parameter
but anyway, I don't even know whether it is methodologically correct to adjust curves to data this way. would you agree bob?
Posted 12 January 2012 - 12:02 PM
It sounds like what you have done in sigmaplot is probably OK, though without actually examining the data it is pretty hard to tell. It may be that there is a simpler curve that fits your data just as well, but I doubt it will make much difference, unless you are looking to extrapolate from your curve.