Arithmetic¶
Operations along one or more axes¶
In Cube objects, the sum
, mean
and
median
methods return the sum, mean and median values along
a given axis or axes of the cube:
In [1]: import matplotlib.pyplot as plt
In [2]: from mpdaf.obj import Cube
In [3]: cube = Cube('sdetect/minicube.fits')
In [4]: cube.info()
[INFO] 3681 x 40 x 40 Cube (sdetect/minicube.fits)
[INFO] .data(3681 x 40 x 40) (1e-20 erg / (Angstrom cm2 s)), .var(3681 x 40 x 40)
[INFO] center:(10:27:56.3962,04:13:25.3588) size:(8.000",8.000") step:(0.200",0.200") rot:-0.0 deg frame:FK5
[INFO] wavelength: min:4749.89 max:9349.89 step:1.25 Angstrom
In [5]: spe = cube.mean(axis=(1,2))
In [6]: spe.info()
[INFO] 3681 Spectrum (sdetect/minicube.fits)
[INFO] .data(3681) (1e-20 erg / (Angstrom cm2 s)), .var(3681)
[INFO] wavelength: min:4749.89 max:9349.89 step:1.25 Angstrom
In [7]: spe.plot()
# white image
In [8]: ima = cube.sum(axis=0)
In [9]: ima.info()
[INFO] 40 x 40 Image (sdetect/minicube.fits)
[INFO] .data(40 x 40) (1e-20 erg / (Angstrom cm2 s)), .var(40 x 40)
[INFO] center:(10:27:56.3962,04:13:25.3588) size:(8.000",8.000") step:(0.200",0.200") rot:-0.0 deg frame:FK5
In [10]: plt.figure()