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# This file is unit01_ArrayOperations.py. It contains a few examples
# of operations on lists and arrays

# George Gollin, University of Illinois, May 20, 2016

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# import a numerical methods library, give it a shorter name.
import numpy as np

# define a couple of lists
a = [2, 3, "dog"]
b = [7, 11, 13, "cat"]

# concatenate the lists:
print("a + b = ", a + b)

# use numpy to create arrays, which can be used for arithmetic operations.
aa = np.array([2, 3, 5])
bb = np.array([7, 9, 11])

# do an element-by-element sum:
print("aa = ", aa)
print("bb = ", bb)
print("aa + bb = ", aa + bb)

# calculate an element-by-element product:
print("aa * bb = ", aa * bb)

# add a scalar to every element of an array. Note the "newline" \n.
print("\naa + 100 = ", aa + 100)

# multiply every element of an array by a scalar
print("\naa * 6 = ", aa * 6)

# take the sqrt of every element of an array
print("\nnp.sqrt(aa) = ", np.sqrt(aa))

# take the square of every element of an array
print("\naa**2 = ", aa**2)

# take the sine of every element of an array
cc = np.array([0., np.pi/6, np.pi/4, np.pi/2])
print("\ncc (radians) = ", cc)
print("np.sin(cc) = ", np.sin(cc))

# convert radians to degrees
print("\nnp.degrees(cc) = ", np.degrees(cc))

# sum the elements in an array
print("\nnp.sum(aa) = ", np.sum(aa))

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