| selrec | Select records according to a boolean expression |
| -d <data> | source data frame |
| -dout <dataout> | output data |
| -expr <expr>; | expression to be evaluated |
| [-v] | verbose evaluation |
This command selects those data records into <dataout>, which produce a TRUE value, when the specified boolean expression is evaluated. Note, that the resulting data has the same fields as the source data. The number of data records might be smaller (or even zero), though. The expression must give a boolean value as a result. More information about expressions can be found in section 4.3.1.
Example (ex4.4): This example selects data records, which represent expensive apartments.
NDA> load boston.dat NDA> selrec -d boston -expr 'boston.rate' > 30; -dout data # Continue analysis for them NDA> prepro -d data -dout predata -e -n NDA> somtr -d predata -sout som1 -l 4 ...