Bug in filterPrecursorScan()

[lgatto]

> library(rpx)
> PXD022816 <- PXDataset("PXD022816")
> (mzmls <- pxget(PXD022816, grep("mzML", pxfiles(PXD022816))[1:2]))
Loading QEP2LC6_HeLa_50ng_251120_01-calib.mzML from cache.
Loading QEP2LC6_HeLa_50ng_251120_02-calib.mzML from cache.
[1] "~/.cache/rpx/207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML"
[2] "~/.cache/rpx/207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML"
> sp <- Spectra(mzmls)
> sp2 <- filterPrecursorScan(sp, 2490)
> length(sp2)
[1] 12

spectraData(sp2)[, c("msLevel", "acquisitionNum", "precScanNum", "dataOrigin")]

msLevel	acquisitionNum	precScanNum	dataOrigin
1	2479	NA	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
2	2480	2479	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
1	2482	NA	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
2	2485	2482	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
1	2486	NA	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
2	2490	2486	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
1	2479	NA	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
1	2480	NA	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
2	2482	2480	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
1	2485	NA	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
2	2486	2485	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
2	2490	2485	207e03973c908_QEP2LC6_HeLa_50ng_251120_02-calib.mzML

Issues

1. First, the acquisition number for all files are extracted, which is probably not what the user wanted. This could be handled explicitly with a call to filterDataOrigin() if I wanted to extract the set from a single file.
2. The result is wrong. We get the acquisition numbers 2490 from the two files, their precursor scans 2485 and 2486 (again from both files), but then these recursively extract each other across different files. The correct results should contain 4 scans:

> spectraData(filterPrecursorScan(filterDataOrigin(sp, unique(dataOrigin(sp))[1]), 2490))[, c("msLevel", "acquisitionNum", "precScanNum", "dataOrigin")]

msLevel	acquisitionNum	precScanNum	dataOrigin
1	2486	NA	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML
2	2490	2486	207e04bccd3dd_QEP2LC6_HeLa_50ng_251120_01-calib.mzML

and

> spectraData(filterPrecursorScan(filterDataOrigin(sp, unique(dataOrigin(sp))[2]), 2490))[, c("msLevel", "acquisitionNum", "precScanNum", "dataOrigin")]

msLevel	acquisitionNum	precScanNum	dataOrigin
1	2485	NA	13707d04ce6b_QEP2LC6_HeLa_50ng_251120_02-calib.mzML
2	2490	248513707d04ce6b_QEP2LC6_HeLa_50ng_251120_02-calib.mzML

Suggested workarounds

• We make filterPrecursorScan() only work with a data from a single data origin ( 👎🏻 )
• We run it on different files to (1) avoid the wrong results (recursive scan selection across files) even though an acquisition should be file specific (not ideal)
• We add a dataOrigin argument (that can be omitted when there's only a single data origin) that needs to be same length at the acquisition number ( 👍🏻 )

@sgibb @jorainer - any comments/suggestions?