/Research_Notes

The other day I was importing email and text messages on my Mac in Stata from the .db files that they are stored in so that I could do some analysis on how often I text/email certain people. I've never been able to get odbc to work on my Mac in Stata, so I cheated with Sqlite3 and imported with:
foreach tbl in chat chat_msg_join message handle chat_handle_join {
! sqlite3 ~/Library/messages/chat.db
! sqlite3 .tables
! sqlite .headers on
! sqlite .mode csv
! sqlite .output /users/ebooth/`tbl'.csv
! sqlite SELECT * FROM `tbl' ;
! sqlite .quit
}

to get my texts.  Merging tables from chat.db is another (very long) story.  

I opened these csv files in Excel to inspect them and noticed that Emoji from the texts were missing (I assumed they'd be converted into some sort of unicode or hex equivalent), but when I imported these messages into Stata I was surprised to see something like the picture to the right where Emoji were being included in Stata (in the results window and data browser…

√-1 2^3 Σ π and it was delicious (because it was of the pizza variety).


My obligatory March 14 Pi  post involves estimating Pi by finding the proportion of randomly plotted points inside a square that are also inside a circumscribed circle. The larger the number of points we plot using this method, the closer to Pi we get (sort of Pi estimation by  simulation in Stata (I know, I know, it should have been programmed in PYthon)).

You can approximate a Pi calculation via boring methods like:
pressing the π on your TI-83 calculator , calculating fractions like 22/7 or 355/113 ,  calculating the log(6)^log(5)^log(4)^log(3)^log(2),  or whatnot. e.g.,

. di  22/7
3.1428571

. di  355/113
3.1415929

. di  log(6)^(log(5)^(log(4)^(log(3)^log(2))))
3.1415774


or just cheat and plot  circles via -tw- functions or -graph pie-, etc in Stata.

However  (assuming you aren't Yasumasa Kanada and Daisuke Takahashi from the U of Tokyo with server cycles to spare)  another approach for calculating Pi is to _draw …