search for: data_dictionari

...d a course at MIT for data preparation that uses python but I'm using R to learning. The first exercise is the preparation of data from a database that shows the contributions made to candidates for U.S. president. The database is described in FORMART ftp://ftp.fec.gov/FEC/Presidential_Map/2012/DATA_DICTIONARIES/CONTRIBUTOR_FORMAT.txt link. I wonder how to print the table showing how many states are President Obama the top candidate (by full amount of donations received) with R language? I try using tapply method but, i dont understand how to working with more than one variable grouped. Could anyone hel...

Hello, I''m wondering if there is any plan to leverage SQL92 INFORMATION_SCHEMA in ActiveRecord? In a nutshell, INFORMATION_SCHEMA provides the meta information necessary to automatically discover all the associations between objects (primary and foreign keys, has_many, has_one and belongs_to, etc). Most relational databases do support this SQL92 standard one way or another*:

I am web scraping a page at http://catalog.ihsn.org/index.php/catalog#_r=&collection=&country=&dtype=&from=1890&page=1&ps=100&sid=&sk=&sort_by=nation&sort_order=&to=2017&topic=&view=s&vk= From this url, I have built up a dataframe through the following code: dflist <- map(.x = 1:417, .f = function(x) { Sys.sleep(5) url <-