Versions Compared

Old Version 8

changes.mady.by.user Richard Dubois

Saved on

compared with

New Version 9

changes.mady.by.user James Chiang

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

  • Python Tools for Analysis and Visualization of Astronomical Data
    • Tools from Space Telescope Science Institute:
      • numarray A replacement for the Numeric package; offers similar array manipulation functionality as matlab or IDL.
      • PyFITS A nice interface for accessing data in FITS files.
      • numdisplay Steer image display using ds9 or ximtool from Python.
      • PyRAF Python replacement for the IRAF command language.
    • matplotlib A default plotting package for Python?\\\\
      An example plot:
      Code Block
      titletest_plot.py
      from matplotlib.matlab import *

def join(x, sign=1):
    x1 = list(x)
    x2 = list(sign*x)
    x1.reverse()
    x1.extend(x2)
    return array(x1)

func = "x**3 - x + 1"
f = eval("lambda x: " + func)

x = arange(-2, 8, 0.01)
y2 = f(x)
indx = where(y2 > 0)
x = x[indx]
y = sqrt(y2[indx])
x = join(x)
y = join(y, -1)

figure(1, figsize=(6, 6))
clf()
plot(x, y, 'k')
xymax = 20
plot([0, 0], [-xymax, xymax], ':b', [-xymax, xymax], [0, 0], ':g')

xx = arange(-1, 8)
yy = sqrt(f(xx))
indx = where((yy % 1) == 0)
plot(xx[indx], yy[indx], "D")

xlabel(r'$x$')
ylabel(r'$y$')
eq = '$y^2 = ' + func.replace('**', '^').replace('*', '') + '$'
legend((eq, '$x=0$', '$y=0$'))

xlim(-1.5, 2)
ylim(-2, 2)

      Here is the result:\\\\
      Image Removed Image Added\\\\
      An example of image display using this package:\\\\
      Code Block
      titledc1_image.py
      import pyfits
from matplotlib.matlab import *

dc1_map = pyfits.open("dc1_counts_map.fits")
dc1_map.info()

im = dc1_map[0].data.copy()

clf()
figure(1, figsize=(8, 4))
       
imshow(log10(im[0] + 1e-5))

      and the resulting image:\\\\
      Image Removed Image Added