Physics307L:Schedule/Week 10 agenda: Difference between revisions

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**Why fitting a line?
**Why fitting a line?
***Linear relations & This versue 1/sqrt(that)
***Linear relations & This versue 1/sqrt(that)
***<math>y=A\e^{Bx}</math>
***<math>y=Ae^{Bx}</math>
**Theoretical
**Theoretical
***Assume gaussian distribution for each <math>y_i</math> with same sigma for all measurements (not necessary, but simplifies it).
***Assume gaussian distribution for each <math>y_i</math> with same sigma for all measurements (not necessary, but simplifies it).

Revision as of 02:18, 22 October 2007

  • Fitting a line
    • AKA linear regression; least-squares fit for a line
    • Why fitting a line?
      • Linear relations & This versue 1/sqrt(that)
      • [math]\displaystyle{ y=Ae^{Bx} }[/math]
    • Theoretical
      • Assume gaussian distribution for each [math]\displaystyle{ y_i }[/math] with same sigma for all measurements (not necessary, but simplifies it).
      • Maximum likelihood...Chi-squared
      • Derivative (minimize Chi-squared) / solve
        • Just show the answer, ... skip derivation for time for practical examples.
    • Practical step by step w/ Excel..."R"...."Octave?"