Hi Steven, > Can I ask you to please post code using plain text rather than HTML > email (also known as "rich text"), as HTML email messes up the > formatting? In this case, I can reverse-engineer the correct formatting, > so no harm done other than a waste of time, but that won't always be so > easy.
Sure Steve, will do so from now on > > Three things stand out: > > (1) The *numerator* of each term is always 4. > > (2) The *denominator* of the terms are 1, 3, 5, ... or to put it another > way, the term in position i has denominator 2*i+1 (starting with i=0). > > (3) The *sign* of the terms are +1, -1, +1, -1, +1, ... If you remember > your high school maths, (-1)**0 = +1, (-1)**1 = -1, (-1)**2 = +1, etc. > So the term in position i has denominator (-1)**i. > > Putting those three things together, the term in position i (starting > with i=0) has value 4.0*(-1)**i/(2*i+1). > > Does that help? It does! I wonder why this simplification never occurred to me. Will implement this and try it out > One other thing: > > > import math > > seed = input("Please enter the number of pairs to calculate: ") > > In Python 2, you shouldn't use input() for user input. It was a design > mistake, which has now been fixed in Python 3, but in Python 2 you > should use raw_input() instead. > > The problem with input() is that it takes the user's input and *executes > it as code*, which could have all sorts of bad side-effects starting > with errors and just getting worse: > > >>> name = input("What is your name? ") > What is your name? Steven > Traceback (most recent call last): > File "<stdin>", line 1, in ? > File "<string>", line 0, in ? > NameError: name 'Steven' is not defined > > Instead, you should say this: > > > seed = int(raw_input("How many terms would you like? ")) > Absolutely. I was just following Zelle's book and he introduces raw_input in the 4th chapter only. I will definitely use the raw_input method, especially as using "input" alone trips up string input Thanks a lot for the help Steve, Sagar _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor