Exercise 5.... continue...

Condividi "Exercise 5.... continue..."

(1)

Exercise 5.... continue...

10) Repeat what you have done in point 8 (random

selection of half the data) and see how things get worst.

11) go back to the original data (saved in the script) and see how fit changes if you add errors to your V_mag (y) data (you must create a vector of same size as y

containing errors). Choose reasonable values for the

errors. (Errors must be all different). See what happens to the fit if you give larger errors to data at larger airmass.

12) Find a way to plot error bars.

(2)

Exercise 6

Find out how to use imsl_kolmogorov2

And establish if (and with which significativity) the 2 following distribution can be considered different)

Data set 1 : 22.06 21.68 21.07 20.91 20.85

20.82 20.72 20.60 20.49 20.36 20.17 19.68 19.66 19.25 18.95 18.90 18.87 18.70

18.67 17.70

Data set 2 : 21.88 21.26 20.84 20.35 20.18

19.75 19.73 19.72 19.66 19.54 19.53 19.52 19.39 19.38 19.10 19.04 18.83 18.76

18,54 18,02

(3)

Exercise 7

Write a routine Idl able to display the theoretical distribution (assuming it is gaussian) of a sample of 3343 galaxies having

 M

 =−20 =0.9

Exercise 5.... continue...

Exercise 5.... continue...

10) Repeat what you have done in point 8 (random

selection of half the data) and see how things get worst.

11) go back to the original data (saved in the script) and see how fit changes if you add errors to your V_mag (y) data (you must create a vector of same size as y

containing errors). Choose reasonable values for the

errors. (Errors must be all different). See what happens to the fit if you give larger errors to data at larger airmass.

12) Find a way to plot error bars.

Exercise 6

Find out how to use imsl_kolmogorov2

And establish if (and with which significativity) the 2 following distribution can be considered different)

Data set 1 : ­22.06 ­21.68 ­21.07 ­20.91 ­20.85

­20.82 ­20.72 ­20.60 ­20.49 ­20.36 ­20.17 ­19.68 ­19.66 ­19.25 ­18.95 ­18.90 ­18.87 ­18.70

­18.67 ­17.70

Data set 2 : ­21.88 ­21.26 ­20.84 ­20.35 ­20.18

­19.75 ­19.73 ­19.72 ­19.66 ­19.54 ­19.53 ­19.52 ­19.39 ­19.38 ­19.10 ­19.04 ­18.83 ­18.76

­18,54 ­18,02

Exercise 7

Write a routine Idl able to display the theoretical distribution (assuming it is gaussian) of a sample of 3343 galaxies having

 M

 =−20 =0.9

Data set 1 : 22.06 21.68 21.07 20.91 20.85

20.82 20.72 20.60 20.49 20.36 20.17 19.68 19.66 19.25 18.95 18.90 18.87 18.70

18.67 17.70

Data set 2 : 21.88 21.26 20.84 20.35 20.18

19.75 19.73 19.72 19.66 19.54 19.53 19.52 19.39 19.38 19.10 19.04 18.83 18.76

18,54 18,02