Re: Lists and Loops
- To: mathgroup at smc.vnet.net
- Subject: [mg113018] Re: Lists and Loops
- From: "Nasser M. Abbasi" <nma at 12000.org>
- Date: Mon, 11 Oct 2010 05:16:25 -0400 (EDT)
- References: <i8s5e7$935$1@smc.vnet.net>
- Reply-to: nma at 12000.org
On 10/10/2010 3:44 AM, Michaell Taylor wrote:
> I am new to Mathematica and am probably too stuck in other languages, but
> but having a hard time with a simple listing building looping structure.
> The code below is supposed to cycle through a list of stock tickers. For
> each ticker it builds a list of certain financial data elements and adds
> each element to a list. When the list is complete (all financial elements
> obtained), the list is written to a Mysql database. The internal looping
> structure seems to work fine. That is, if I execute the internal loop for a
> single ticker, the results are added to the database as planned.
>
> However, the outer structure causes a problem in that the list continues to
> grow with each ticker. The "mydata={}" line was meant to "reset" the list,
> but doesn't seem to be performing as expected.
>
> tickers = {"VNO", "AMB"}
>
> fprop = {"Average50Day", "Average200Day"}
>
> Do[
> mydata = {t}
> Do[
> mydata = Append[mydata, FinancialData[t, i]],
> {i, fprop}]
> Print[mydata]
> SQLInsert[connt, "reit" , {"ticker", "first", "second"}, mydata]
> {t, tickers}]
>
>
> My error, no doubt is obvious to some. Any guidance would be greatly
> appreciated.
>
>
OMG! , you are using loops in Mathematica :)
If I understand what you want, how about this:
tickers = {"GE", "IBM", "GOOG"};
fprop = {"Average50Day", "Average200Day"};
Outer[FinancialData, tickers, fprop];
data = Join[Transpose[{tickers}], %, 2];
TableForm[data]
GE 15.8406 16.5046
IBM 130.134 128.736
GOOG 491.243 502.399
--Nasser