Here are some recommendations and comments on fitting data.
In many cases, to analyze the data recorded during experiments you will need to fit and plot your data. There are large number of good fitting programs available.
MICROSOFT Excel is marginally acceptable but lacks flexibility. Fitting is difficult and handling of error bars is weak. Some powerful free programs that work well are “gnuplot” and ROOT. They can be downloaded from the WEB.
“gnuplot” has been used in the past by PHYS480L and PHYS481L students.
(“ROOT” is extremely powerful and flexible but may take time to learn. Very popular in high energy and nuclear physics.)
It is extremely important to plot the data with error bars of the correct size, which reflect the statistical and systematic uncertainties in the measurements.