Hello All, I asked myself how I could use sage to compute the standard deviation of a grade distribution for one of my courses. Rooting around, I found that I can compute for example
sage: vector(RDF,[1,2,2,1]).standard_deviation() and get the answer 0.57735026919. However, if I try the same command with "RDF" replaced by "RR," I get anAttributeError. My first question is: What's going on here; how come RDF and RR are so different in this context? Their respective descriptions look very similar -- "An approximation to the field of real numbers using double precision floating point numbers. Answers derived from calculations in this approximation may differ from what they would be if those calculations were performed in the true field of real numbers. This is due to the rounding errors inherent to finite precision calculations." "An approximation to the field of real numbers using floating point numbers with any specified precision. Answers derived from calculations in this approximation may differ from what they would be if those calculations were performed in the true field of real numbers. This is due to the rounding errors inherent to finite precision calculations." If I had found some documentation about the standard deviation command, I would probably have have found the answer to my first question. This leads to my second question: Why I don't I see information about standard_deviation when I type "standard_deviation?" at the command line? Thanks in advance for the help! Ken Ribet -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org To unsubscribe, reply using "remove me" as the subject.
