StepPolMap

class sofia_redux.instruments.hawc.steps.steppolmap.StepPolMap

Bases: StepParent

Generate a polarization map image.

This pipeline step calls sofia_redux.visualization.quicklook.make_image to generate a PNG image for quick-look purposes from polarization data in the input. This step must be run after sofia_redux.instruments.hawc.steps.StepRegion. It expects a ‘FINAL POL DATA’ table extension in the input DataFits.

The output from this step is identical to the input. As a side effect, a PNG file is saved to disk to the same base name as the input file, with ‘PMP’ replacing the product type indicator.

Methods Summary

run()	Run the data reduction algorithm.
setup()	Set parameters and metadata for the pipeline step.

Methods Documentation

run()

Run the data reduction algorithm.

Because this step is single-in, single-out (SISO), self.datain must be a DataFits object. The output is also a DataFits object, stored in self.dataout.

The process is:

1. Read image data and polarization table data.

2. Generate a plot with vectors overlaid on a flux image.

setup()

Set parameters and metadata for the pipeline step.

Output files have PRODTYPE = ‘polmap’, and are named with the step abbreviation ‘PMP’.

Parameters defined for this step are:

maphdustr

Extension name to use as the background image.

lowhighscalelist of float

Specify a low and high percentile value for the image scale, e.g. [0,99].

scalevecfloat

Scale factor for sizing polarization vectors.

scalebool

If set, vector lengths are scaled by their magnitude. If not, all vectors will be the same length.

rotatebool

If set, vectors are rotated to display B-field directions.

debiasbool

If set, the debiased polarizations are used to determine the vectors.

colorvecstr

Vector color.

colorcontourstr

Contour color.

colormapstr

Image colormap.

ncontoursint

Number of contour levels.

fillcontoursbool

If set, the contours will be filled, rather than just overlaid on the image.

gridbool

If set, a grid will be overlaid on the image.

titlestr

A title string. If set to ‘info’, a title will be automatically generated.

centercropbool

If set, the image will be cropped, using the values in the ‘centercropparams’ parameter.

centercropparamslist of float

Cropping area to use if centercrop = True. Should be a 4-element list of [RA center (deg), Dec center (deg, box width (deg), box height (deg)].

watermarkstr

Text to add to the plot as a watermark.