Hide keyboard shortcuts

Hot-keys on this page

r m x p   toggle line displays

j k   next/prev highlighted chunk

0   (zero) top of page

1   (one) first highlighted chunk

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

 

__all__ = ["denormalizeMatches"] 

 

import lsst.afw.table 

 

 

def denormalizeMatches(matches, matchMeta=None): 

"""Generate a denormalized Catalog of matches 

 

This is intended for writing matches in a convenient way. 

Normally we write matches in a 'normalized' form: recording only the join 

table (reference ID, source ID) to minimise space (the reference and source 

catalogs should both be available separately, so the only extra information 

we need is how to join them). However, using that can be a pain, since it 

requires reading each catalog and doing the join. 

 

This function generates a Catalog containing all the information in the 

matches. The reference catalog entries are in columns with "ref_" 

prepended, while the source catalog entries are in columns with "src_" 

prepended. The distance between the matches is in a column named 

"distance". 

 

Parameters 

---------- 

matches : `list` of `lsst.afw.table.ReferenceMatch` 

List of matches between reference catalog and source catalog. 

matchMeta : `lsst.daf.base.PropertyList` 

Matching metadata to write in catalog. 

 

Returns 

------- 

catalog : `lsst.afw.table.BaseCatalog` 

Catalog containing matchlist entries. 

 

See also 

-------- 

`lsst.afw.table.packMatches` 

""" 

39 ↛ 40line 39 didn't jump to line 40, because the condition on line 39 was never true if len(matches) == 0: 

raise RuntimeError("No matches provided.") 

 

refSchema = matches[0].first.getSchema() 

srcSchema = matches[0].second.getSchema() 

 

refMapper, srcMapper = lsst.afw.table.SchemaMapper.join([refSchema, srcSchema], ["ref_", "src_"]) 

schema = refMapper.editOutputSchema() 

distKey = schema.addField("distance", type=float, doc="Distance between ref and src") 

 

catalog = lsst.afw.table.BaseCatalog(schema) 

catalog.reserve(len(matches)) 

for mm in matches: 

row = catalog.addNew() 

row.assign(mm.first, refMapper) 

row.assign(mm.second, srcMapper) 

row.set(distKey, mm.distance) 

 

57 ↛ 58line 57 didn't jump to line 58, because the condition on line 57 was never true if matchMeta is not None: 

catalog.getTable().setMetadata(matchMeta) 

 

return catalog