行列演算とPythonの言語デザイン

4. "Python has arguably become the de facto
standard for exploratory, interactive, and
computation-driven scientific research”

10. •L[i, j, k]
•L[1:2, ..., 2:3]
L[i][j][k] L[i,j,k]

11. A = A*2
A *= 2

12. A = B*C*D*E
X1 = B*C
X2 = X1*D
A = X2*E
A = B*C
A *= D
A *= E

13. X = (A < B)
X = (A.__cmp__(B) == -1)
X = A.__lt__(B)

14. >>> x = np.random.rand(5)
>>> x
array([0.90081264, 0.22836483, 0.34013548,
0.83180827, 0.22866072])
>>> y = (x >= 0.5)
>>> y
array([ True, False, False, True, False])
>>> x[x >= 0.5]
array([0.90081264, 0.83180827])

15. >>> A =[1, 2, 3]
>>> A[1]
2
>>> A[np.int64(1)]
2

17. A @ B
np.matmul(A, B)

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