Hello,(adsbygoogle = window.adsbygoogle || []).push({});

I have done a chi squared test on the measurements from a neutron flux experiment to get the best parameters for a function of the form Ysim=Acos(B*X). I used Solver in Excel to find the minimum parameters. The test takes the form

chi^2 / dof = SUM(Ysim-Yi)^2/(sigma i)^2

Where Yi are the measured values of the flux at various heights and (sigma i) is the uncertainty in flux i.

What I want to do is to find the uncertainty in the parameter B. I have been told that if I shift the parameter B until the minimum value of chi^2 is altered to get chi^2 + 1 then the difference between the original value for B and the new value for B can be used to get the uncertainty in B.

Does this make any kind of mathematical sense? I've found hints that this is equivalent to garbageing chi^2 by one standard deviation but I have not found any hard evidence of this. Has anyone seen this method referenced anywhere?

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Finding Uncertainty in a coefficient with a Chi Squared Test

Loading...

Similar Threads for Finding Uncertainty coefficient | Date |
---|---|

I Confusion over using integration to find probability | Jun 27, 2017 |

I How To Find 68% Confidence Interval After Running MCMC | May 29, 2017 |

I Finding the average time with given probability | Apr 21, 2017 |

Finding the Uncertainty of the Slope Parameter of a Liner Regression | Mar 1, 2014 |

How do you find the uncertainty in a function of two variables? | Sep 30, 2012 |

**Physics Forums - The Fusion of Science and Community**