[Tempo2] Using 'select' files in tempo2

[George Hobbs]

Dear tempo2 users,

  The sourceforge code for tempo2 has had a few updates recently. One of the largest changes has been the development of the use of 'select' files.  Now you can produce a file (called a 'select file') that defines which data tempo2 will use.  For instance, for the Parkes pulsar timing array project we observe with multiple frequencies and backend systems.  We can now produce files like:

-----
PASS TOAERR 0. 1.0
REJECT MJD 55179.5 55181.2
PASS FREQ 1200 1600
PROCESS SIMUL -f MULTI_PDFB2 MULTI_PDFB4 TOAERR 1500
PROCESS SIMUL -f MULTI_PDFB2 MULTI_PDFB1 TOAERR 1500
----

This file (called, for instance, 20cm.sel) can be run with:

>tempo2 -gr plk -f mypar.par mytim.tim -select 20cm.sel

The file makes tempo2:
1. select only observations with TOA uncertainties between 0us and 1us (PASS TOAERR 0. 1.0)
2. delete all observations with MJDs between 55179.5 and 55181.2 (REJECT MJD 55179.5 55181.2)
3. select only the 20cm observations (PASS FREQ 1200 1600)
4. find simultaneous points (where simultaneous means that the TOAs are with 1500s of each other - the default is 60s) for which one point has a flag "-f MULTI_PDFB2" and the other point has a flag "-f MULTI_PDFB4".  For each of these simultaneous points the observation with the largest TOAERR is removed. (PROCESS SIMUL -f MULTI_PDFB2 MULTI_PDFB4 TOAERR 1500)

---
The commands implemented so far are:

Reject commands
=============

REJECT FREQ <freq1> <freq2>		Rejects all points with frequencies between freq1 and freq2
REJECT MJD <mjd1> <mjd2>			Rejects all points with MJDs between mjd1 and mjd2
REJECT TOAERR <e1> <e2> 			Rejects all points with TOAERRs between e1 and e2

Pass commands
=============

PASS FREQ <freq1> <freq2>			Select only points with frequencies between freq1 and freq2
PASS MJD <mjd1> <mjd2>			Select only points with MJDs between mjd1 and mjd2
PASS TOAERR <e1> <e2>			Select only points with TOAERRs between e1 and e2

Process commands
===============

PROCESS SIMUL <flagID> <flag1> <flag2> <command>  <time>
									Determines all points that are simultaneous (within time <time> - default = 60s) with given flagID and flag values set to flag1 or flag2 and then
									processes them according to the command.

									command = only		deletes all other observations
									command = toaerr	selects the simultaneous point with the smallest toaerr
									command = 1		selects only the point with flag value = flag1
									command = 2		selects only the point with flag value = flag2

									example: PROCESS SIMUL -f MULTI_PDFB1 MULTI_PDFB2 toaerr
									will remove the largest error bar observation for all simultaneous MULTI_PDFB1 and MULTI_PDFB2 observations

PROCESS <flagID> <flagVal> <command> <val1> <val2>
									Determines all points with given flagID and flagValue and then processes them according to the command
				
									command = mjdpass	Only selects those points with MJDs between <val1> and <val2>
									command = mjdreject Rejects those points with MJDs between <val1> and <val2>
									command = errpass	Only selects those points with TOAERRs between <val1> and <val2>
									command = errreject	Rejects those points with MJDs between <val1> and <val2>
									command = freqpass	Only selects those points with frequencies between <val1> and <val2>
									command = freqreject Rejects those points with frequencies between <val1> and <val2>

----
hopefully you'll find these commands useful.

Cheers,
 George







-------------------------------------------------------
George Hobbs
Australia Telescope National Facility
02 93724652
george.hobbs at csiro.au