📄 dbclass.ox
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#include <oxstd.h>
#import <database> // required to use Database class
main()
{ decl dbase, y, dy, names;
dbase = new Database(); // create new object
dbase->Load("data/data.xls"); // load data
dbase->Info(); // print database info
// select variables
dbase->Select(0, { "CONS", 0, 0, "INC", 0, 0 } );
dbase->Select(1, { "CONS", 1, 1, "INC", 1, 1 } );
dbase->SetSelSample(1953, 1, 1992, 3); // and sample
y = dbase->GetGroup(0); // extract group 0
dy = y - dbase->GetGroup(1);
names = {"CONS", "INC", "DCONS", "DINC"};
print("\nsample variance over ",
dbase->GetSelSample(),
"%r", names, "%c", names, variance(y ~ dy) );
println("\nnumber of observations: ", dbase->GetSize());
println("period of observation 9: ", dbase->ObsYear(9),
" (", dbase->ObsPeriod(9), ")");
println("database index 1985(4): ", dbase->GetIndex(1985,4));
delete dbase; // done with object, delete it
}
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