Python: Operações com Arrays do módulo Numpy

= Operações com Arrays=

Criando um array com o Numpy
>>> from numpy import *

>>> arr = array([1,2,4,7,5,9]) >>> print(arr) [1 2 4 7 5 9] >>> print(arr.dtype) int64

>>> arr = array([1,2,4,7,5.3]) >>> print(arr) [ 1.  2.   4.   7.   5.3] >>>print(arr.dtype) float64

Operações Vetorizadas
>>> arr = array([2,4,7,6,1]) >>> arr = arr + 5 >>> print(arr) [ 7 9 12 11  6]

>>> print pow(arr,2) [ 49 81 144 121  36] >>> arr2 = array([3,1,-2,-1,4]) >>> arr3 = arr + arr2 >>> print(arr3) [10 10 10 10 10]

Copia de arrays
>>> arr = array([1,3,9,8,2]) >>> arr2 = arr >>> arr3 = arr.view >>> arr4 = arr.copy >>> arr[1] = 7

>>> print(arr) [1 7 9 8 2] >>> print(arr2) [1 7 9 8 2] >>> print(arr3) [1 7 9 8 2] >>> print(arr4) [1 3 9 8 2]

>>> print(id(arr)) 4518341328 >>> print(id(arr2)) 4518341328 >>> print(id(arr3)) 4518341008 >>> print(id(arr4)) 4532265488

arange
>>> arr = arange(1,15,2) >>> print arr [ 1 3  5  7  9 11 13]

zeros
>>> arr = zeros(5) >>> print arr [ 0. 0.  0.  0.  0.]

ones
>>> arr = ones(7) >>> print arr [ 1. 1.  1.  1.  1.  1.  1.]

>>> arr = ones(7,int) >>> print arr [1 1 1 1 1 1 1]

logspace
>>> arr = logspace(1,15,2) >>> print arr [ 1.00000000e+01   1.00000000e+15]

linspace
Cria partes

>>> arr = linspace(0,2,3) >>> print arr [ 0. 1.  2.]

>>> arr = linspace(0,5,4) >>> print arr [ 0.         1.66666667  3.33333333  5.        ]

= Ver também =


 * Artigos sobre Python