Computer Labs

• ep208-labSheets.pdf
• QUIZ PAGE

Additional Notes on Least Square Fitting:

1. Data file for the inverse square law
   

   Light source (LED)      Light detector
   
       /
      o --                       D
       \
   
       <----------- x ----------->
   
   * DATA
   file isl_data.txt
   first  column (x): Distance in meter
   second column (I): Light intensity in %
   
   
   * FIT
   General model:
          f(x) = a/x^n
   Coefficients (with 95% confidence bounds):
          a =       38.27  (38.12, 38.42)
          n =       1.952  (1.931, 1.972)
   
   Goodness of fit:
      S: 18.14
     r2: 0.9969
   
   gnuplot> plot "isl_data.txt", 38.27/x**1.952
   

   
   
   

2. Notes on the Hanging Chain

   y(x) = A cosh(x/A) -A

   Data:

   x = {-1.0000,   -0.8000,   -0.6000,   -0.4000,   -0.2000,    0.0000,    0.2000,    0.4000,    0.6000,    0.8000,    1.0000};
   y = { 0.5000,    0.3300,    0.1900,    0.0800,    0.0200,    0.0000,    0.0200,    0.0900,    0.1700,    0.3000,    0.5000};
   
   gnuplot> plot [-1:1] 1/0.8*cosh(0.8*x)-1/0.8, 0.42*x**2