Error uncertainty for power law


by johnnnnyyy
Tags: error, power, uncertainty
johnnnnyyy
johnnnnyyy is offline
#1
Jan17-14, 08:50 PM
P: 16
So I have a series of 5 data points lets say that they are (1,1),(2,3),(3,4),(4,4.5),(5,4.75) that create a power function that has the equation y=1.2x^.97. Lets also say that the error uncertainty for every number is 0.1. I know that for a linear line you can take the uncertainty of the slope by finding the largest possible slope and the smallest possible slope but how would you do it for a power function?
Phys.Org News Partner Physics news on Phys.org
Better thermal-imaging lens from waste sulfur
Scientists observe quantum superconductor-metal transition and superconducting glass
New technique detects microscopic diabetes-related eye damage
Simon Bridge
Simon Bridge is offline
#2
Jan17-14, 10:10 PM
Homework
Sci Advisor
HW Helper
Thanks ∞
PF Gold
Simon Bridge's Avatar
P: 10,952
What do you want to find the uncertainty of?

Guessing:

For data suspected to be of form ##y=ax^b## ... where a and b are to be found...
notice that: ##\log(y)=\log(a)+b\log(x)##

... a plot of log(y) vs log(x) should yield a line with slope b and intercept log(a).
Find the uncertainties normally ... make sure your errorbars are correct, they are no longer symmetric.


There are also more rigorous statistical approaches to getting uncertainties in the parameters of a regressed curve but I'm guessing you don't need to go that far.


Register to reply

Related Discussions
Measurement uncertainty and error Introductory Physics Homework 25
Density and error/uncertainty Introductory Physics Homework 0
Uncertainty error calculations Advanced Physics Homework 3
How do you count Uncertainty Measurement using Precision Error and Bias Error? Engineering, Comp Sci, & Technology Homework 0
uncertainty/error question Introductory Physics Homework 1