Dira2: DB_HISTO

The db_histo command display an istogram of the field values present in the catalogues.

More catalogues a time can be superimpose

New values (numerical functions of values present in the catalogue fields) can be evaluated "on the fly" and used in the histogram. In the example the two lines shows the difference MADIAMR-MIDIAMR and MADIAMB-MIDIAMB of the UGC catalogue.