Contents

shapepipe.modules.setools_package

shapepipe.modules.setools_package

SETOOLS PACKAGE.

This package contains the module(s) for setools.

Author

Axel Guinot

Parent module

sextractor_runner

Input

SExtractor catalogue

Output

SExtractor catalogue

Description

This module defines samples via selection criteria, or masks. A variety of statistical mathematical functions are implemented, that can be applied to the input catalogue.

The setools module can create random sub-sample output catalogues, for example for training and validation purposes.

In addition, the module can produce user-defined plots, and compute summary statistics of the selected population(s). The figures include scatter plots and histograms, the summaries are number, mean, mode, extrema, and standard deviation.

Module-specific config file entries

SETOOLS_CONFIG_PATHstr

Path to setools configuration file

Setools configuration file

This file can contain an arbitrary number of sections. Each section is initiated by a line [TYPE:name]. The following mask types TYPE are valid.

  • MASK: define a selection or mask

  • RAND_SPLIT: split an input into random subsamples

  • PLOT: create a plot

  • STATS: output summary statistics

name is the file name, in which the result of the section is saved. This is a FITS file for MASK, .png file for PLOT, and an ASCII file for STATS. For TYPE = MASK and RAND_SPLIT, name is also the reference, by which the defined sample can be addressed within the configuration file.

The following is an example of a star selection using two MASK sections. First, a pre-selection is defined:

[MASK:preselect]
MAG_AUTO > 0
MAG_AUTO < 21
FWHM_IMAGE > 0.3 / 0.187
FWHM_IMAGE < 1.5 / 0.187
FLAGS == 0
IMAFLAGS_ISO == 0
NO_SAVE

This selects objects within a magnitude (MAG_AUTO) and size (FWHM_IMAGE) ranges. The size limits of 0.3” and 1.5” are transformed from arcseconds to pixels. Additional flag criteria for FLAGS AND IMAFLAGS_ISO are specified. The keyword NO_SAVE indicates that this selection is not to be saved to disk.

Next, the final star selection is defined:

[MASK:star_selection]
MAG_AUTO > 18.
MAG_AUTO < 22.
FWHM_IMAGE <= mode(FWHM_IMAGE{preselect}) + 0.2
FWHM_IMAGE >= mode(FWHM_IMAGE{preselect}) - 0.2
FLAGS == 0
IMAFLAGS_ISO == 0

The size range is now refined using the mode of preselected objects. The preselection removes outliers before the mode computation.

An example of the definition of random subsamples is as follows:

[RAND_SPLIT:star_split]
RATIO = 20
MASK = star_selection

This uses as input the star_selection sample (given by the MASK entry). It creates two random subsamples: one with 20% and one with 80% (100 - RATIO) percent of input objects. The output file base names are given by the mask name and the ratios; in this case two files star_split_ratio_20-<num>.fits and star_split_ratio_80-<num>.fits are created, where <num> is the pipeline number of the (single-exposure single-HDU) image that is processed.

Entries in the MASK and STATS sections, lines can contain basic relational operations, and functions.

The operands can be

  • input column names, or SExtractor keywords,

  • or names defined by a previous mask.

The following are illustrations of two plots. First, another mask is defined.

[MASK:fwhm_mag_cut]
FWHM_IMAGE > 0
FWHM_IMAGE < 40
MAG_AUTO < 35
FLAGS == 0
IMAFLAGS_ISO == 0
NO_SAVE

[PLOT:size_mag]
TYPE = plot
FORMAT = png
X_1 = FWHM_IMAGE{fwhm_mag_cut}
Y_1 = MAG_AUTO{fwhm_mag_cut}
X_2 = FWHM_IMAGE{star_selection}
Y_2 = MAG_AUTO{star_selection}
MARKER_1 = +
MARKER_2 = .
MARKERSIZE_1 = 3
MARKERSIZE_2 = 3
LABEL_1 = All
LABEL_2 = "Stars, mean FWHM: @mean(FWHM_IMAGE{star_selection})*0.187@arcsec"
TITLE = "Stellar locus"
XLABEL = "FWHM (pix)"
YLABEL = Mag

[PLOT:hist_mag_stars]
TYPE = hist
FORMAT = png
Y = MAG_AUTO{star_selection}
BIN = 20
LABEL = "stars"
XLABEL = "Magnitude"
YLABEL = "Number"
TITLE = "Magnitude of stars"

Possible values for TYPE are plot, histogram, scatter. More than one sample can be plotted by adding _1, _2, … to all of the above given keywords.

Keywords for all plot types:

Ystr

Functions of samples to plot on y-axis

XLABEL, YLABELstr, optional

Labels for x- and y-axes, respectively

LABELstr, optional

Plot label

TITLEstr, optional

Plot title

ALPHAfloat

Alpha (transparency) parameter

COLORstr, optional

Plot color; the default is the standard matplotlib color sequence

FORMATstr, optional

Output file format; the default value is png

Keywords for standard and scatter plots (TYPE in plot, scatter):

Xstr

Functions of samples to plot on x-axis

MARKERstr, optional

Point marker symbol; the default value is +

Additional keywords for standard line/points plot (TYPE = plot):

MARKERSIZEfloat, optional

Marker size; the default value is 1

LINEstr, optional

Line type

Additional keywords for histograms (TYPE = hist):

BINint, optional

Number of bins; the default value is 50

HTYPEstr, optional

Histogram type; the default value is bar

LOGbool, optional

Logarithmic (linear) bins if True (False); the defaul value is False

Additional keywords for scatter plots (TYPE = scatter):

MARKERstr

Point marker

SCATTERstr, optional

Function of some input sample acting as third variable that is color-coded in the point colors.

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