torchtest 0.5

= torchtest

A Tiny Test Suite for pytorch based Machine Learning models, inspired by https://github.com/Thenerdstation/mltest/blob/master/mltest/mltest.py[mltest].
Chase Roberts lists out 4 basic tests in his https://medium.com/@keeper6928/mltest-automatically-test-neural-network-models-in-one-function-call-eb6f1fa5019d[medium post] about mltest.
torchtest is mostly a pytorch port of mltest(which was written for tensorflow).

== Installation

[source, bash]
----
pip install --upgrade torchtest
----

== Tests


[source, python]
----
# imports for examples
import torch
import torch.nn as nn
import torch.nn.functional as F
from torch.autograd import Variable
----


=== Variables Change

[source, python]
----
from torchtest import assert_vars_change

inputs = Variable(torch.randn(20, 20))
targets = Variable(torch.randint(0, 2, (20,))).long()
batch = [inputs, targets]
model = nn.Linear(20, 2)

# what are the variables?
print('Our list of parameters', [ np[0] for np in model.named_parameters() ])

# do they change after a training step?
# let's run a train step and see
assert_vars_change(
model=model,
loss_fn=F.cross_entropy,
optim=torch.optim.Adam(model.parameters()),
batch=batch)
----

[source, python]
----
""" FAILURE """
# let's try to break this, so the test fails
params_to_train = [ np[1] for np in model.named_parameters() if np[0] is not 'bias' ]
# run test now
assert_vars_change(
model=model,
loss_fn=F.cross_entropy,
optim=torch.optim.Adam(params_to_train),
batch=batch)

# YES! bias did not change
----


=== Variables Don't Change

[source, python]
----
from torchtest import assert_vars_same

# What if bias is not supposed to change, by design?
# test to see if bias remains the same after training
assert_vars_same(
model=model,
loss_fn=F.cross_entropy,
optim=torch.optim.Adam(params_to_train),
batch=batch,
params=[('bias', model.bias)]
)
# it does? good. let's move on
----

=== Output Range

[source, python]
----
from torchtest import test_suite

# NOTE : bias is fixed (not trainable)
optim = torch.optim.Adam(params_to_train)
loss_fn=F.cross_entropy

test_suite(model, loss_fn, optim, batch,
output_range=(-2, 2),
test_output_range=True
)

# seems to work
----

[source, python]
----
""" FAILURE """
# let's tweak the model to fail the test
model.bias = nn.Parameter(2 + torch.randn(2, ))

test_suite(
model,
loss_fn, optim, batch,
output_range=(-1, 1),
test_output_range=True
)

# as expected, it fails; yay!
----

=== NaN Tensors

[source, python]
----
""" FAILURE """
model.bias = nn.Parameter(float('NaN') * torch.randn(2, ))

test_suite(
model,
loss_fn, optim, batch,
test_nan_vals=True
)
----

=== Inf Tensors

[source, python]
----
""" FAILURE """
model.bias = nn.Parameter(float('Inf') * torch.randn(2, ))

test_suite(
model,
loss_fn, optim, batch,
test_inf_vals=True
)
----