Pytorch view -1 meaning

View(-1) in pytorch

import torch

x = torch.arange(6)

print(x.view(3, -1))      # inferred size will be 2 as 6 / 3 = 2
# tensor([[ 0.,  1.],
#         [ 2.,  3.],
#         [ 4.,  5.]])

print(x.view(-1, 6))      # inferred size will be 1 as 6 / 6 = 1
# tensor([[ 0.,  1.,  2.,  3.,  4.,  5.]])

print(x.view(1, -1, 2))   # inferred size will be 3 as 6 / (1 * 2) = 3
# tensor([[[ 0.,  1.],
#          [ 2.,  3.],
#          [ 4.,  5.]]])

# print(x.view(-1, 5))    # throw error as there's no int N so that 5 * N = 6
# RuntimeError: invalid argument 2: size '[-1 x 5]' is invalid for input with 6 elements

print(x.view(-1, -1, 3))  # throw error as only one dimension can be inferred
# RuntimeError: invalid argument 1: only one dimension can be inferred

Source: stackoverflow.com

Pytorch view -1 meaning

If there is any situation that you don't know how many rows you want but are sure of the number of columns, then you can specify this with a -1. (Note that you can extend this to tensors with more dimensions. Only one of the axis value can be -1). This is a way of telling the library: "give me a tensor that has these many columns and you compute the appropriate number of rows that is necessary to make this happen".

Similar codes

-1 vote138 views2 answers
How to convert 2 dimensional in 1 dimensional array
Python
0 vote151 views4 answers
Beautifulsoup parent
Python
0 vote135 views2 answers
Extra error
Python
33 votes141 views10 answers
Elon musk
Python
10 votes121 views1 answer
Create dataframe with column names pandas
Python
10 votes120 views5 answers
Progress bar in cmd python
Python
0 vote215 views1 answer
Cuda memory in pytorch
Python
0 vote115 views1 answer
How to print class attributes in python
Python
0 vote118 views1 answer
Poython inl linrt dor loop
Python
15 votes88 views2 answers
Python copy image to clipboard
Python