Coding the Matrix-3장 Vector

Charpter3. Vector

In [8]:

import math

s=[3.14159, 2.718281828, -1.0, 2.0]

e=list(enumerate(s))

print(e)

[(0, 3.14159), (1, 2.718281828), (2, -1.0), (3, 2.0)]

In [11]:

list(zip([1,2,3,4], [1,2,3,4]))

Out[11]:

[(1, 1), (2, 2), (3, 3), (4, 4)]

In [14]:

%matplotlib inline

import numpy as np

import matplotlib.pyplot as plt

limit=4

s=[2+2j, 3+2j, 1.75+1j, 2+1j, 2.25+1j, 2.5+1j, 2.75+1j, 3+1j, 3.25+1j]

for x in range(len(s)) :

    plt.plot(s[x].real, s[x].imag, 'ro-', label='complex')

    ##  plt.plot([0,s[x].real], [0, s[x].imag])

plt.xlim(-limit,limit)

plt.ylim(-limit,limit)

plt.ylabel('Imaginary')

plt.xlabel('Real')  

plt.grid(True)

plt.show()

In [16]:

%matplotlib inline

import numpy as np

import matplotlib.pyplot as plt

limit=4

soa = np.array([0,0,3,1.5])

X,Y,U,V = zip(soa)

ax = plt.gca()

ax.quiver(X,Y,U,V,  angles='xy', scale_units='xy', scale=1)

ax.set_xlim([-5,5])

ax.set_ylim([-5,5])

plt.draw()

plt.grid(True)

plt.show()

In [18]:

u=[1,1,1,1,1]

v=[10,20,0,40,-100]

sum(u*v for (u,v) in list(zip(u,v)))

Out[18]:

-30