CatMatcher Quickstart

1. Module import

[5]:

import os
import pandas as pd
from stilts_wrapper.matcher import StiltsMatcher

2. Setup

To use CatMatcher, users need to provide a path to the directory holding the files they would like to perform a cross-match on. Since the STILTS backend works with relative path variables for the matching process, the users are also prompted to provide a directory name. CatMatcher will then create a directory with that name inside the file directory, along with the file structure needed to run STILTS in the background.

[6]:

file_path = '../../Data/example_files/'
files = [f for f in os.listdir(file_path) if "csv" in f]

files

[6]:

['Megeath_YSOs.csv', 'Nemesis_YSOs_OrionB.csv', 'Disks_NGC2024.csv']

3. Define Match parameters

[7]:

match_values = ["RAJ2000 DEJ2000", "RA DE", "RAJ2000 DEJ2000"]  # Names of the columns to match
match_radius = 1  # arcseconds

4. Performing a simple match

All the matching functionality is encapsulated in the StiltsMatcher class.

[8]:

# Initialize Matcher
Nmatcher = StiltsMatcher(
    file_list=files,
    file_path=file_path,
    output_file_name="test.csv",  # name of the output file
    ifmt="csv",
    match_radius=match_radius,
    match_values=match_values,
    join_mode="match",
)

csv ['test', 'csv']

[9]:

Nmatcher.build_N_match(print_command=True)

Command written to /Users/alena/PycharmProjects/CatMatcher/Data/example_files/CatMatcher_cwd/scripts/Nmatch_commands
stilts tmatchn multimode=group nin=3 matcher=sky params=1 \
        in1=../../Megeath_YSOs.csv ifmt1=csv suffix1='_1' values1='RAJ2000 DEJ2000' \
        in2=../../Nemesis_YSOs_OrionB.csv ifmt2=csv suffix2='_2' values2='RA DE' \
        in3=../../Disks_NGC2024.csv ifmt3=csv suffix3='_3' values3='RAJ2000 DEJ2000' \
        join1=match     join2=match join3=match \
        fixcols=dups out=../matches/test.csv ofmt=csv progress=time

[10]:

Nmatcher.perform_Nmatch()

Command written to /Users/alena/PycharmProjects/CatMatcher/Data/example_files/CatMatcher_cwd/scripts/Nmatch_commands
Output: Current directory: /Users/alena/PycharmProjects/CatMatcher/Data/example_files/CatMatcher_cwd/scripts

Error: Params: Max Error(Number)/arcsec=1.0
Tuning: HEALPix k(Integer)=14
Processing: Split, BasicParallel
Binning rows for table 1......................................................
Time: 0.0s
Binning rows for table 2......................................................
Time: 0.0s
Binning rows for table 3......................................................
Time: 0.0s
Average bin count per row: 1.0820783
4894 row refs in 4311 bins
(average bin occupancy 1.1352354)
Consolidating potential match groups..........................................
Time: 0.0s
Locating pairs................................................................
Time: 0.0s
Eliminating internal links....................................................
Time: 0.0s
Internal links removed: 1
Mapping rows to links.........................................................
Time: 0.0s
Identifying isolated links....................................................
Time: 0.0s
Walking links..............................................................
Time: 0.0s
Eliminating internal links....................................................
Time: 0.0s
Elapsed time for match: 0 seconds
Populate index maps...........................................................
Time: 0.0s
Params: Max Error(Number)/arcsec=1.0
Tuning: HEALPix k(Integer)=14
Processing: Split, BasicParallel
Binning rows for table 1......................................................
Time: 0.0s
Binning rows for table 2......................................................
Time: 0.0s
Binning rows for table 3......................................................
Time: 0.0s
Average bin count per row: 1.0820783
4894 row refs in 4311 bins
(average bin occupancy 1.1352354)
Consolidating potential match groups..........................................
Time: 0.0s
Locating pairs................................................................
Time: 0.0s
Eliminating internal links....................................................
Time: 0.0s
Internal links removed: 1
Mapping rows to links.........................................................
Time: 0.0s
Identifying isolated links....................................................
Time: 0.0s
Walking links..............................................................
Time: 0.0s
Eliminating internal links....................................................
Time: 0.0s
Elapsed time for match: 0 seconds
Populate index maps...........................................................
Time: 0.0s

Return code: 0