Are the values returned by numpy.empty() random or not?
$begingroup$
https://docs.scipy.org/doc/numpy-1.15.0/reference/generated/numpy.empty.html
reads that "Return a new array of given shape and type, without initializing entries."
Q1:what do "without initializing entries." mean here.
Q2:Are the output returned by np.empty() are random numbers?
I am using below code to generate an array and I am getting same output so how could they be random numbers?
import numpy as np
print(np.empty([2,2]))
numpy
edited 7 mins ago
Wes
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asked 16 hours ago
Vinay SharmaVinay Sharma
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$endgroup$
add a comment |
$begingroup$
https://docs.scipy.org/doc/numpy-1.15.0/reference/generated/numpy.empty.html
reads that "Return a new array of given shape and type, without initializing entries."
Q1:what do "without initializing entries." mean here.
Q2:Are the output returned by np.empty() are random numbers?
I am using below code to generate an array and I am getting same output so how could they be random numbers?
import numpy as np
print(np.empty([2,2]))
numpy
edited 7 mins ago
Wes
1469
asked 16 hours ago
Vinay SharmaVinay Sharma
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
https://docs.scipy.org/doc/numpy-1.15.0/reference/generated/numpy.empty.html
reads that "Return a new array of given shape and type, without initializing entries."
Q1:what do "without initializing entries." mean here.
Q2:Are the output returned by np.empty() are random numbers?
I am using below code to generate an array and I am getting same output so how could they be random numbers?
import numpy as np
print(np.empty([2,2]))
numpy
edited 7 mins ago
Wes
1469
asked 16 hours ago
Vinay SharmaVinay Sharma
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
https://docs.scipy.org/doc/numpy-1.15.0/reference/generated/numpy.empty.html
reads that "Return a new array of given shape and type, without initializing entries."
Q1:what do "without initializing entries." mean here.
Q2:Are the output returned by np.empty() are random numbers?
I am using below code to generate an array and I am getting same output so how could they be random numbers?
import numpy as np
print(np.empty([2,2]))
numpy
numpy
edited 7 mins ago
Wes
1469
asked 16 hours ago
Vinay SharmaVinay Sharma
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 mins ago
Wes
1469
asked 16 hours ago
Vinay SharmaVinay Sharma
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 7 mins ago
Wes
1469
edited 7 mins ago
Wes
1469
edited 7 mins ago
Wes
1469
1469
asked 16 hours ago
Vinay SharmaVinay Sharma
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 16 hours ago
Vinay SharmaVinay Sharma
61
asked 16 hours ago
Vinay SharmaVinay Sharma
61
61
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Vinay Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
1 Answer
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$begingroup$
The array is allocated in memory but each item in the area is uninitialized just like an uninitialized variable. In other words, the items in the array have not had their values set and are just taking the value that was held in memory until you explicitly assign them a value. Sometimes this value is 0 or close to it, but there is no guarantee what was in memory at those locations. Here is the note on the reference page:
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.
So unless you have a certain use case, go with zeros or something else. I'll also note that typically Python does not allow you to just declare a variable without initializing it, which is why this behavior might seem strange.
answered 14 hours ago
WesWes
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1 Answer
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1 Answer
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$begingroup$
The array is allocated in memory but each item in the area is uninitialized just like an uninitialized variable. In other words, the items in the array have not had their values set and are just taking the value that was held in memory until you explicitly assign them a value. Sometimes this value is 0 or close to it, but there is no guarantee what was in memory at those locations. Here is the note on the reference page:
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.
So unless you have a certain use case, go with zeros or something else. I'll also note that typically Python does not allow you to just declare a variable without initializing it, which is why this behavior might seem strange.
answered 14 hours ago
WesWes
1469
New contributor
Wes is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
The array is allocated in memory but each item in the area is uninitialized just like an uninitialized variable. In other words, the items in the array have not had their values set and are just taking the value that was held in memory until you explicitly assign them a value. Sometimes this value is 0 or close to it, but there is no guarantee what was in memory at those locations. Here is the note on the reference page:
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.
So unless you have a certain use case, go with zeros or something else. I'll also note that typically Python does not allow you to just declare a variable without initializing it, which is why this behavior might seem strange.
answered 14 hours ago
WesWes
1469
New contributor
Wes is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
The array is allocated in memory but each item in the area is uninitialized just like an uninitialized variable. In other words, the items in the array have not had their values set and are just taking the value that was held in memory until you explicitly assign them a value. Sometimes this value is 0 or close to it, but there is no guarantee what was in memory at those locations. Here is the note on the reference page:
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.
So unless you have a certain use case, go with zeros or something else. I'll also note that typically Python does not allow you to just declare a variable without initializing it, which is why this behavior might seem strange.
answered 14 hours ago
WesWes
1469
New contributor
Wes is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
The array is allocated in memory but each item in the area is uninitialized just like an uninitialized variable. In other words, the items in the array have not had their values set and are just taking the value that was held in memory until you explicitly assign them a value. Sometimes this value is 0 or close to it, but there is no guarantee what was in memory at those locations. Here is the note on the reference page:
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.
So unless you have a certain use case, go with zeros or something else. I'll also note that typically Python does not allow you to just declare a variable without initializing it, which is why this behavior might seem strange.
answered 14 hours ago
WesWes
1469
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Wes is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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answered 14 hours ago
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answered 14 hours ago
WesWes
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answered 14 hours ago
WesWes
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