Lec3 LeastSquaresFit

Lec3 LeastSquaresFit - Gaussian Distribution Physics 257...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 257 Lecture 3: Least Squares Fit Prof. Matt Dobbs Physics Department, McGill U. Prof. M. Dobbs, Physics 257 Sept 27, 2007 2 Gaussian Distribution Question from last class: where does the Gauss distribution come from? ± Used in the 1730s by de Moivre as the limiting case for large N binomial distributions. Later extended by Laplace Æ Theorem of Moivre-Laplace ± Legendre introduced method of least squares in 1805 – Gauss gave a formal justification for the method in 1809 by assuming the errors were distributed in according to the Normal Distribution. Prof. M. Dobbs, Physics 257 Sept 27, 2007 3 Summary - Distributions ± Flat (roll of a die) ± Gaussian or normal (average heart rate of Canadian males) z Central limit theorem means that nature produces Gaussian distributions OFTEN. ± Poisson (counting – number of heads or tails) Prof. M. Dobbs, Physics 257 Sept 27, 2007 4 Review: Central Limit Theorem ± http://www.math.csusb.edu/faculty/stanton/probst at/clt.html
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Prof. M. Dobbs, Physics 257 Sept 27, 2007 5 Outline ± Questions ? ± Intro to χ 2 ± Least squares fitting to straight lines ± Why Δ x= ±1/ 12 z When doesn’t this apply? Prof. M. Dobbs, Physics 257 Sept 27, 2007 6 Lab / Asst Feedback ± Remember the checklists for graphing and read the instructions carefully . ± Discussions: z Quote the result (but do not repeat all details) z Discuss the experimental results and errors. z Were your results consistent with expectation? If not, why not? How can the expt be improved? ± Always show example calculation or spreadsheet. z You can use software like MS Equation Editor or a typesetter like Latex. z If you’re not comfortable with these, you may write the example calculation equations carefully and clearly by hand. (Everything else, including graphs, must be computer generated for the lab reports).
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/29/2008 for the course PHYS 257 taught by Professor Dobbs during the Fall '07 term at McGill.

Page1 / 7

Lec3 LeastSquaresFit - Gaussian Distribution Physics 257...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online