# This script reduces field after field and outputs the mean offset of all
# matches between usno-b and ppmx.

import makecross

from gavo import api
from gavo import config
from gavo import sqlsupport

def findSingleCorrection(band, survey, field):
	table = "usnob.offsetfind"
	makecross.makeCrossTable(table, band, survey, field)
	with api.getTableConn() as conn:
		return list(conn.query(
			"SELECT sum(alphaPPMX-alphaEp)/count(*),"
			" sum(deltaPPMX-deltaEp)/count(*) FROM %s"%table))[0]

if __name__=="__main__":
	config.setDbProfile("feed")
	band = "B1"
	survey = 'A'
	for field in range(1, 200):
		print band, survey, field, findSingleCorrection(band, survey, field)