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# Empty

An Empty NumPy array is an array filled with only zero or near-zero values. The arrays can be of any shape.

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### Imports¶

This tutorial imports Plotly and Numpy.

In [1]:
import plotly.plotly as py
from plotly.tools import FigureFactory as FF

import numpy as np


#### Empty Array¶

The np.empty() function is used to create a 2D array filled with all zeros. Often the array is filled with values near zero because of the way memory and RAM works in the computer.

In [2]:
import plotly.plotly as py
from plotly.tools import FigureFactory as FF

shape = (4, 6)

zeros_array = np.empty(shape)

colorscale = [[0, 'rgb(49, 52, 92)'], [1, 'rgb(49, 52, 92)']]
font_colors = ['rgb(255, 255, 255)']

table = FF.create_table(zeros_array, colorscale, font_colors)
py.iplot(table, filename='numpy-empty')

Out[2]:
In [2]:
help(np.empty)

Help on built-in function empty in module numpy.core.multiarray:

empty(...)
empty(shape, dtype=float, order='C')

Return a new array of given shape and type, without initializing entries.

Parameters
----------
shape : int or tuple of int
Shape of the empty array
dtype : data-type, optional
Desired output data-type.
order : {'C', 'F'}, optional
Whether to store multi-dimensional data in row-major
(C-style) or column-major (Fortran-style) order in
memory.

Returns
-------
out : ndarray
Array of uninitialized (arbitrary) data of the given shape, dtype, and
order.  Object arrays will be initialized to None.

--------
empty_like, zeros, ones

Notes
-----
empty, unlike zeros, does not set the array values to zero,
and may therefore be marginally faster.  On the other hand, it requires
the user to manually set all the values in the array, and should be
used with caution.

Examples
--------
>>> np.empty([2, 2])
array([[ -9.74499359e+001,   6.69583040e-309],
[  2.13182611e-314,   3.06959433e-309]])         #random

>>> np.empty([2, 2], dtype=int)
array([[-1073741821, -1067949133],
[  496041986,    19249760]])                     #random


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