Transcript APLpy Annotation

Python Crash Course
Aplpy
3rd year Bachelors
V1.0
dd 06-09-2013
Hour 3
APLpy
APLpy (the Astronomical Plotting Library in Python) is a Python module
aimed at producing publication-quality plots of astronomical imaging
data in FITS format. The module uses Matplotlib and is capable of
creating output files in several graphical formats, including EPS, PDF,
PS, PNG, and SVG.
See http://aplpy.github.io for documentation
Main features
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Make plots interactively or using scripts
Show grayscale, colorscale, and 3-color RGB images of FITS files
Generate co-aligned FITS cubes to make 3-color RGB images
Make plots from FITS files with arbitrary WCS (e.g. position-velocity)
Slice multi-dimensional FITS cubes
Overlay any number of contour sets
Overlay markers with fully customizable symbols
Plot customizable shapes like circles, ellipses, and rectangles
Overlay ds9 region files
Overlay coordinate grids
Show colorbars, scalebars, and beams
Customize the appearance of labels and ticks
Hide, show, and remove different contour and marker layers
Pan, zoom, and save any view as a full publication-quality plot
Save plots as EPS, PDF, PS, PNG, and SVG
APLpy
• Intro
>>> import aplpy
>>> fig = aplpy.FITSFigure('myimage.fits')
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fig.show_grayscale()
fig.hide_grayscale()
fig.show_colorscale()
fig.hide_colorscale()
# Scaling and panning
>>> fig.recenter(33.23, 55.33, width=0.3, height=0.2)
# Overlaying
>>> fig.show_contour('co_data.fits')
# save for publication
>>> fig.save('myplot.eps')
# degrees
APLpy
• Labels and shapes en DS9 Regions
>>> fig.add_label(34.455, 54.112, 'My favorite star')
>>> fig.add_label(0.1, 0.9, '(a)', relative=True)
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fig.show_markers(x_world, y_world)
# 1D arrays in degrees
fig.show_circles(x_world, y_world, radius)
fig.show_ellipses(x_world, y_world, width, height)
fig.show_rectangles(x_world, y_world, width, height)
fig.show_arrows(x_world, y_world, dx, dy)
>>> fig.show_lines(line_list)
>>> fig.show_polygons(polygon_list)
>>> fig.show_regions('myregions.reg')
# 2xN ndarray’s of vertices in degrees
APLpy
• Layers
>>> fig.list_layers()
>>> fig.hide_layer('regions')
>>> fig.show_layer('regions')
>>> layer = fig.get_layer('circles')
>>> fig.remove_layer('rectangles')
• Coordinates
>>> x_pix, y_pix = fig.world2pixel(45.3332, 22.1932)
>>> x_world, y_world = fig.pixel2world(np.array([1., 2., 3]), np.array([1., 3., 5.]))
APLpy Annotation
• Colorbar, Coordinate Grid, Scalebar, Beam
>>> fig.add_colorbar()
>>> fig.colorbar.set_width(0.1)
>>> fig.add_grid()
>>> fig.grid.set_xspacing(0.2) # degrees
>>> fig.grid.set_color('white')
>>> fig.add_scalebar()
>>> fig.scalebar.set_length(0.02) # degrees
>>> fig.scalebar.set_label('5 pc')
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fig.add_beam()
fig.beam.set_major(0.03) # degrees
fig.beam.set_minor(0.02) # degrees
fig.beam.set_angle(45.) # degrees
APLpy Annotation
• Axis labels, Tick, Ticks
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fig.axis_labels.show()
fig.axis_labels.show_x()
fig.axis_labels.set_xtext('Right Ascension (J2000)')
fig.axis_labels.set_xpad(...)
fig.axis_labels.set_ypad(...) # set displacement
fig.axis_labels.set_xposition('bottom')
>>> fig.tick_labels.show()
>>> fig.tick_labels.set_xformat('hh:mm:ss.ss')
>>> fig.tick_labels.set_xposition('top')
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fig.ticks.show()
fig.ticks.set_xspacing(0.04) # degrees
fig.ticks.set_color('black')
fig.ticks.set_linewidth(2) # points
APLpy – Practical example
• M33 plot (get data through skycat)
>>>import aplpy
gc = aplpy.FITSFigure('/disks/strw2/deul/m33.fits')
gc.show_grayscale()
gc.show_colorscale()
gc.show_colorscale(cmap='gist_heat')
gc.tick_labels.set_font(size='small')
gc.add_grid()
gc.remove_grid()
APLpy – Practical example
• Overplot GSC (get data from http://vizier.u-strasbg.fr/)
from astropy.io.votable import parse
import astropy.io.votable as vot
gsc_table = vot.parse("/home/deul/Documents/m33_gsc.vot")
table = gsc_table.get_first_table()
r=table.array['_RAJ2000']
d=table.array['_DEJ2000']
s = ones(len(r))*0.003
gc.show_circles(r,d,s)
gc.list_layers()
gc.hide_layer('circle_set_1')
gc.show_layer('circle_set_1')
l = gc.get_layer('circle_set_1')
l.set_edgecolor('green')
APLpy – Practical example
• Overplot 2MASS (get data from http://vizier.u-strasbg.fr/)
from astropy.io.votable import parse
import astropy.io.votable as vot
gsc_table = vot.parse("/home/deul/Documents/m33_2mass.vot")
table = gsc_table.get_first_table()
r=table.array['_RAJ2000']
d=table.array['_DEJ2000']
s = ones(len(r))*0.003
gc.show_circles(r,d,s)
gc.list_layers()
gc.hide_layer('circle_set_2')
gc.show_layer('circle_set_2')
l = gc.get_layer('circle_set_2')
l.set_edgecolor(‘blue')
Introduction to language
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