Contenido del Curso
Ultimate NumPy
3. Commonly used NumPy Functions
Ultimate NumPy
Random Arrays
It is often the case that we need to generate a random number or an array of random numbers. Luckily, NumPy has a module named random
specifically for this purpose.
Note
random
generates pseudo-random numbers, not truly random numbers. However, for most purposes, this is more than enough.
The two most commonly used functions of the random
module are:
rand()
;randint()
.
rand()
The numpy.random.rand()
function is used to generate either a random float
number or an array of random floats from a uniform distribution over [0, 1).
Its only possible arguments are the dimensions of the array. If no argument is passed, rand()
generates a random float
number (scalar).
Let’s clarify with an example:
First, we generated a random float
number. Next, we generated a random 1D array with 5 elements by setting its size to 5
. Finally, we generated a random 2D array of shape 3x4
.
Note
Dimensions in the
rand()
function should be specified as separate integer parameters, not a tuple of integers.
randint()
The numpy.random.randint
function is used to generate either a random integer or an array of random integers from a
discrete uniform distribution within a specified interval.
Its three most important parameters are low
(the only required parameter), high
, and size
. The interval is [low, high)
(from low
inclusive to high
exclusive). However, if high
is not specified, then the interval is [0, low)
.
Let’s look at an example:
There is actually nothing complicated here; everything is rather straightforward.
Note
Unlike
rand()
, we specify the dimensions of the array via a single parametersize
, passing either an integer or a tuple of integers.
As always, here is the documentation for you: numpy.random.rand and numpy.random.randint.
Tarea
- Create a 1D array of random floats from a uniform distribution in [0, 1) with 4 elements for
random_floats_array
. - Create a 2D array of random floats from a uniform distribution in [0, 1) with a shape of 3x2 for
random_floats_matrix
. - Use the correct function to create a 2D array of random integers for
random_integers_matrix
. - Set the interval to [10, 21) (from
10
to21
exclusive) by specifying the first two arguments of the function. - Set the shape of the
random_integers_matrix
to 3x2 by specifying the third keyword argument of the function.
¿Todo estuvo claro?
Contenido del Curso
Ultimate NumPy
3. Commonly used NumPy Functions
Ultimate NumPy
Random Arrays
It is often the case that we need to generate a random number or an array of random numbers. Luckily, NumPy has a module named random
specifically for this purpose.
Note
random
generates pseudo-random numbers, not truly random numbers. However, for most purposes, this is more than enough.
The two most commonly used functions of the random
module are:
rand()
;randint()
.
rand()
The numpy.random.rand()
function is used to generate either a random float
number or an array of random floats from a uniform distribution over [0, 1).
Its only possible arguments are the dimensions of the array. If no argument is passed, rand()
generates a random float
number (scalar).
Let’s clarify with an example:
First, we generated a random float
number. Next, we generated a random 1D array with 5 elements by setting its size to 5
. Finally, we generated a random 2D array of shape 3x4
.
Note
Dimensions in the
rand()
function should be specified as separate integer parameters, not a tuple of integers.
randint()
The numpy.random.randint
function is used to generate either a random integer or an array of random integers from a
discrete uniform distribution within a specified interval.
Its three most important parameters are low
(the only required parameter), high
, and size
. The interval is [low, high)
(from low
inclusive to high
exclusive). However, if high
is not specified, then the interval is [0, low)
.
Let’s look at an example:
There is actually nothing complicated here; everything is rather straightforward.
Note
Unlike
rand()
, we specify the dimensions of the array via a single parametersize
, passing either an integer or a tuple of integers.
As always, here is the documentation for you: numpy.random.rand and numpy.random.randint.
Tarea
- Create a 1D array of random floats from a uniform distribution in [0, 1) with 4 elements for
random_floats_array
. - Create a 2D array of random floats from a uniform distribution in [0, 1) with a shape of 3x2 for
random_floats_matrix
. - Use the correct function to create a 2D array of random integers for
random_integers_matrix
. - Set the interval to [10, 21) (from
10
to21
exclusive) by specifying the first two arguments of the function. - Set the shape of the
random_integers_matrix
to 3x2 by specifying the third keyword argument of the function.
¿Todo estuvo claro?