On Sat, Jul 4, 2009 at 12:09 PM, Steven Buck<bucks...@gmail.com> wrote:
> I've used a module (StataTools) from (http://presbrey.mit.edu/PyDTA ) to get > a Stata ".dta" file into Python. In Stata the data set is an NXK matrix > where N is the number of observations (households) and K is the number of > variables. > I gather it's now a list where each element of the list is an observation (a > vector) for one household. The name of my list is "data"; I gather Python > recognizes the first observation by: data[1] . > Example, > data = [X_1, X_2, X_3, . . . . , X_N] where each X_i for all i, is vector > of household characteristics, eg X_1 = (age_1, wage_1, . . . , residence_1). > > I also have a list for variable names called "varname"; although I'm not > sure the module I used to extract the ".dta" into Python also created a > correspondence between the varname list and the data list--the python > interpreter won't print anything when I type one of the variable names, I > was hoping it would print out a vector of ages or the like. varname is probably just a list of strings without any direct connection to the data. > In anycase, I'd like to make a scatter plot in pylab, but don't know how to > identify a variable in "data" (i.e. I'd like a vector listing the ages and > another vector listing the wages of households). Perhaps, I need to run > subroutine to collect each relevant data point to create a new list which I > define as my variable of interest? From the above example, I'd like to > create a list such as: age = [age_1, age_2, . . . , age_N] and likewise for > wages. You can use a list comprehension to collect columns from the data. If age is the first element of each observation (index 0), and wages the second (index 1), then ages = [ observation[0] for observation in data ] wages = [ observation[1] for observation in data ] > Any help you could offer would be very much appreciated. Also, this is my > first time using the python tutor, so let me know if I've used it > appropriately or if I should change/narrow the structure of my question. It's very helpful if you show us the code you have so far. Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
