1.2. Warm up

In this tutorial, you will learn basic use of numpy and matplotlib that are employed in the manipulation of nucleardatapy.

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Import numpy library.

# Import numpy
import numpy as np

Generate a numpy array with linspace(). Documentation is there: https://numpy.org/doc/stable/reference/generated/numpy.linspace.html

vec = np.linspace( 0.01, 0.31, num = 5 )
print( vec )

[0.01  0.085 0.16  0.235 0.31 ]

Generate a vector density with logspace() (https://numpy.org/doc/stable/reference/generated/numpy.logspace.html):

logvec = np.logspace(-5, -1, num = 10, base = 10)
print( logvec )

[1.00000000e-05 2.78255940e-05 7.74263683e-05 2.15443469e-04
 5.99484250e-04 1.66810054e-03 4.64158883e-03 1.29154967e-02
 3.59381366e-02 1.00000000e-01]

Generate a vector with constant asymmetry parameter asy.

For SM, where asy is a vector of zeros:

asy = np.zeros( vec.size )
print( asy )

[0. 0. 0. 0. 0.]

For NM, where asy is a vector of ones:

asy = np.ones( vec.size )
print( asy )

[1. 1. 1. 1. 1.]

For AM, where asy is any value between 0 and 1:

asy = 0.5 * np.ones( vec.size )
print( asy )

[0.5 0.5 0.5 0.5 0.5]

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Now we draw some plots.

Import the matplotlib library as well as nucleardatapy to get some data.

# Import matplotlib package
import matplotlib.pyplot as plt
# Import nucleardatapy package
import nucleardatapy as nuda

Load the energy per particle from APR equation of state and instantiate the object apr:

apr = nuda.matter.setupMicro( model = '1998-VAR-AM-APR' )
print('den in SM:',apr.sm_den)
print('energy per particle in SM:',apr.sm_e2a)

model ->  1998-VAR-AM-APR
flag_nm: True
flag_sm: True
flag_kf: False
flag_den: True
den in SM: [0.04 0.08 0.12 0.16 0.2  0.24 0.32 0.4  0.48 0.56 0.64 0.8  0.96]
energy per particle in SM: [ 932.4386795  926.7886795  923.8786795  922.9186795  923.8286795
  926.0386795  933.8886795  941.0486795  954.3786795  973.3086795
  997.2686795 1060.1686795 1142.9386795]

Plot the binding energy as function of the particle density (using plot https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.plot.html):

plt.xlabel(r'density $n$ (fm$^{-3}$)')
plt.ylabel(r'energy per particle $E/A$ (MeV)')
plt.plot( apr.sm_den, apr.sm_e2a, label = apr.label )
plt.legend(loc='upper left')

<matplotlib.legend.Legend at 0x7f4f6cbbe9f0>

Now put errorbars in the plot (using errorbar https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.errorbar.html):

plt.errorbar( apr.sm_den, apr.sm_e2a, yerr = apr.sm_e2a_err, label = apr.label )
plt.legend(loc='upper left')

<matplotlib.legend.Legend at 0x7f4f6d261550>