I'm trying to build a service that has 2 components. In component 1, I train a machine learning model using sklearn by creating a Pipeline. This model gets serialized using joblib.dump (really numpy_pickle.dump). Component 2 runs in the cloud, loads the model trained by (1), and uses it to label text that it gets as input.
I'm running into an issue where, during training (component 1) I need to first binarize my data since it is text data, which means that the model is trained on binarized input and then makes predictions using the mapping created by the binarizer. I need to get this mapping back when (2) makes predictions based on the model so that I can output the actual text labels.
I tried adding the binarizer to the pipeline like this, thinking that the model would then have the mapping itself:
p = Pipeline([
('binarizer', MultiLabelBinarizer()),
('vect', CountVectorizer(min_df=min_df, ngram_range=ngram_range)),
('tfidf', TfidfTransformer()),
('clf', OneVsRestClassifier(clf))
])
But I get the following error:
model = p.fit(training_features, training_tags)
*** TypeError: fit_transform() takes 2 positional arguments but 3 were given
My goal is to make sure the binarizer and model are tied together so that the consumer knows how to decode the model's output.
What are some existing paradigms for doing this? Should I be serializing the binarizer together with the model in some other object that I create? Is there some other way of passing the binarizer to Pipeline so that I don't have to do that, and would I be able to get the mappings back from the model if I did that?
Your intuition that you should add the MultiLabelBinarizer to the pipeline was the right way to solve this problem. It would have worked, except that MultiLabelBinarizer.fit_transform does not take the fit_transform(self, X, y=None) method signature which is now standard for sklearn estimators. Instead, it has a unique fit_transform(self, y) signature which I had never noticed before. As a result of this difference, when you call fit on the pipeline, it tries to pass training_tags as a third positional argument to a function with two positional arguments, which doesn't work.
The solution to this problem is tricky. The cleanest way I can think of to work around it is to create your own MultiLabelBinarizer that overrides fit_transform and ignores its third argument. Try something like the following.
class MyMLB(MultiLabelBinarizer):
def fit_transform(self, X, y=None):
return super(MultiLabelBinarizer, self).fit_transform(X)
Try adding this to your pipeline in place of the MultiLabelBinarizer and see what happens. If you're able to fit() the pipeline, the last problem that you'll have is that your new MyMLB class has to be importable on any system that will de-pickle your now trained, pickled pipeline object. The easiest way to do this is to put MyMLB into its own module and place a copy on the remote machine that will be de-pickling and executing the model. That should fix it.
I misunderstood how the MultiLabelBinarizer worked. It is a transformer of outputs, not of inputs. Not only does this explain the alternative fit_transform() method signature for that class, but it also makes it fundamentally incompatible with the idea of inclusion in a single classification pipeline which is limited to transforming inputs and making predictions of outputs. However, all is not lost!
Based on your question, you're already comfortable with serializing your model to disk as [some form of] a .pkl file. You should be able to also serialize a trained MultiLabelBinarizer, and then unpack it and use it to unpack the outputs from your pipeline. I know you're using joblib, but I'll write this up this sample code as if you're using pickle. I believe the idea will still apply.
X = <training_data>
y = <training_labels>
# Perform multi-label classification on class labels.
mlb = MultiLabelBinarizer()
multilabel_y = mlb.fit_transform(y)
p = Pipeline([
('vect', CountVectorizer(min_df=min_df, ngram_range=ngram_range)),
('tfidf', TfidfTransformer()),
('clf', OneVsRestClassifier(clf))
])
# Use multilabel classes to fit the pipeline.
p.fit(X, multilabel_y)
# Serialize both the pipeline and binarizer to disk.
with open('my_sklearn_objects.pkl', 'wb') as f:
pickle.dump((mlb, p), f)
Then, after shipping the .pkl files to the remote box...
# Hydrate the serialized objects.
with open('my_sklearn_objects.pkl', 'rb') as f:
mlb, p = pickle.load(f)
X = <input data> # Get your input data from somewhere.
# Predict the classes using the pipeline
mlb_predictions = p.predict(X)
# Turn those classes into labels using the binarizer.
classes = mlb.inverse_transform(mlb_predictions)
# Do something with predicted classes.
<...>
Is this the paradigm for doing this? As far as I know, yes. Not only that, but if you desire to keep them together (which is a good idea, I think) you can serialize them as a tuple as I did in the example above so they stay in a single file. No need to serialize a custom object or anything like that.
Model serialization via pickle et al. is the sklearn approved way to save estimators between runs and move them between computers. I've used this process successfully many times before, including in productions systems with success.
Related
I've been trying to generate human pose estimations, I came across many pretrained models (ex. Pose2Seg, deep-high-resolution-net ), however these models only include scripts for training and testing, this seems to be the norm in code written to implement models from research papers ,in deep-high-resolution-net I have tried to write a script to load the pretrained model and feed it my images, but the output I got was a bunch of tensors and I have no idea how to convert them to the .json annotations that I need.
total newbie here, sorry for my poor English in advance, ANY tips are appreciated.
I would include my script but its over 100 lines.
PS: is it polite to contact the authors and ask them if they can help?
because it seems a little distasteful.
Im not doing skeleton detection research, but your problem seems to be general.
(1) I dont think other people should teaching you from begining on how to load data and run their code from begining.
(2) For running other peoples code, just modify their test script which is provided e.g
https://github.com/leoxiaobin/deep-high-resolution-net.pytorch/blob/master/tools/test.py
They already helps you loaded the model
model = eval('models.'+cfg.MODEL.NAME+'.get_pose_net')(
cfg, is_train=False
)
if cfg.TEST.MODEL_FILE:
logger.info('=> loading model from {}'.format(cfg.TEST.MODEL_FILE))
model.load_state_dict(torch.load(cfg.TEST.MODEL_FILE), strict=False)
else:
model_state_file = os.path.join(
final_output_dir, 'final_state.pth'
)
logger.info('=> loading model from {}'.format(model_state_file))
model.load_state_dict(torch.load(model_state_file))
model = torch.nn.DataParallel(model, device_ids=cfg.GPUS).cuda()
Just call
# evaluate on Variable x with testing data
y = model(x)
# access Variable's tensor, copy back to CPU, convert to numpy
arr = y.data.cpu().numpy()
# write CSV
np.savetxt('output.csv', arr)
You should be able to open it in excel
(3) "convert them to the .json annotations that I need".
That's the problem nobody can help. We don't know what format you want. For their format, it can be obtained either by their paper. Or looking at their training data by
X, y = torch.load('some_training_set_with_labels.pt')
By correlating the x and y. Then you should have a pretty good idea.
I have built an Microsoft Azure ML Studio workspace predictive web service, and have a scernario where I need to be able to run the service with different training datasets.
I know I can setup multiple web services via Azure ML, each with a different training set attached, but I am trying to find a way to do it all within the same workspace and passing a Web Input Parameter as the input value to choose which training set to use.
I have found this article, which describes almost my scenario. However, this article relies on the training dataset that is being pulled from the Load Trained Data module, as having a static endpoint (or blob storage location). I don't see any way to dynamically (or conditionally) change this location based on a Web Input Parameter.
Basically, does Azure ML support a "conditional training data" loading?
Or, might there be a way to combine training datasets, then filter based on the passed Web Input Parameter?
This probably isn't exactly what you need, but hopefully, it helps you out.
To combine data sets, you can use the Join Data module.
To filter, that may be accomplished by executing a Python script. Here's an example.
Using the Adult Census Income Binary Classification dataset, on the age column, there's a minimum age of 17.
If I wanted to filter the data set by age, connect it to an Execute Python Script module and here's the filtering code with the pandas query method.
# The script MUST contain a function named azureml_main
# which is the entry point for this module.
import pandas as pd
def azureml_main(dataframe1 = None, dataframe2 = None):
# Return value must be of a sequence of pandas.DataFrame
return dataframe1.query("age >= 25")
And looking at that output it filters out the data set where the minimum age is now 25.
Sure, you can do that. What you would want is to use an Execute R Script or SQL Transformation module to determine, based on your input data, what model to use. Something like this:
Notice, your input data is cleaned/updated/feature engineered, then it's passed to two different SQL transforms which will tell it to go to one of two paths.
Each path has it's own training data.
Note: I am not exactly sure what your use case is, but if it were me, I would instead train two different models using the two different training data, then try to just use the models in my web service, not actually train on the web service as that would likely be quite slow.
Every TensorFlow example I've seen uses placeholders to feed data into the graph. But my applications work fine without placeholders. According to the documentation, using placeholders is the "best practice", but they seem to make the code unnecessarily complex.
Are there any occasions when placeholders are absolutely necessary?
According to the documentation, using placeholders is the "best practice"
Hold on, this quote is out-of-context and could be misinterpreted. Placeholders are the best practice when feeding data through feed_dict.
Using a placeholder makes the intent clear: this is an input node that needs feeding. Tensorflow even provides a placeholder_with_default that does not need feeding — but again, the intent of such a node is clear. For all purposes, a placeholder_with_default does the same thing as a constant — you can indeed feed the constant to change its value, but is the intent clear, would that not be confusing? I doubt so.
There are other ways to input data than feeding and AFAICS all have their uses.
A placeholder is a promise to provide a value later.
Simple example is to define two placeholders a,b and then an operation on them like below .
a = tf.placeholder(tf.float32)
b = tf.placeholder(tf.float32)
adder_node = a + b # + provides a shortcut for tf.add(a, b)
a,b are not initialized and contains no data Because they were defined as placeholders.
Other approach to do same is to define variables tf.Variable and in this case you have to provide an initial value when you declare it.
like :
tf.global_variables_initializer()
or
tf.initialize_all_variables()
And this solution has two drawbacks
Performance wise that you need to do one extra step with calling
initializer however these variables are updatable .
in some cases you do not know the initial values for these variables
so you have to define it as a placeholder
Conclusion :
use tf.Variable for trainable variables such as weights (W) and biases (B) for your model or when Initial values are required in
general.
tf.placeholder allows you to create operations and build computation graph, without needing the data. In TensorFlow
terminology, we then feed data into the graph through these
placeholders.
I really like Ahmed's answer and I upvoted it, but I would like to provide an alternative explanation that might or might not make things a bit clearer.
One of the significant features of Tensorflow is that its operation graphs are compiled and then executed outside of the original environment used to build them. This allows Tensorflow do all sorts of tricks and optimizations, like distributed, platform independent calculations, graph interoperability, GPU computations etc. But all of this comes at the price of complexity. Since your graph is being executed inside its own VM of some sort, you have to have a special way of feeding data into it from the outside, for example from your python program.
This is where placeholders come in. One way of feeding data into your model is to supply it via a feed dictionary when you execute a graph op. And to indicate where inside the graph this data is supposed to go you use placeholders. This way, as Ahmed said, placeholder is a sort of a promise for data supplied in the future. It is literally a placeholder for things you will supply later. To use an example similar to Ahmed's
# define graph to do matrix muliplication
x = tf.placeholder(tf.float32)
y = tf.placeholder(tf.float32)
# this is the actual operation we want to do,
# but since we want to supply x and y at runtime
# we will use placeholders
model = tf.matmul(x, y)
# now lets supply the data and run the graph
init = tf.global_variables_initializer()
with tf.Session() as session:
session.run(init)
# generate some data for our graph
data_x = np.random.randint(0, 10, size=[5, 5])
data_y = np.random.randint(0, 10, size=[5, 5])
# do the work
result = session.run(model, feed_dict={x: data_x, y: data_y}
There are other ways of supplying data into the graph, but arguably, placeholders and feed_dict is the most comprehensible way and it provides most flexibility.
If you want to avoid placeholders, other ways of supplying data are either loading the whole dataset into constants on graph build or moving the whole process of loading and pre-processing the data into the graph by using input pipelines. You can read up on all of this in the TF documentation.
https://www.tensorflow.org/programmers_guide/reading_data
I am using a custom image set to train a neural network using Tensorflow API. After successful training process I get these checkpoint files containing values of different training var. I now want to get an inference model from these checkpoint files, I found this script which does that, which I can then use to generate deepdream images as explained in this tutorial. The problem is when I load my model using:
import tensorflow as tf
model_fn = 'export'
graph = tf.Graph()
sess = tf.InteractiveSession(graph=graph)
with tf.gfile.FastGFile(model_fn, 'rb') as f:
graph_def = tf.GraphDef()
graph_def.ParseFromString(f.read())
t_input = tf.placeholder(np.float32, name='input')
imagenet_mean = 117.0
t_preprocessed = tf.expand_dims(t_input-imagenet_mean, 0)
tf.import_graph_def(graph_def, {'input':t_preprocessed})
I get this error:
graph_def.ParseFromString(f.read())
self.MergeFromString(serialized)
raise message_mod.DecodeError('Unexpected end-group tag.')
google.protobuf.message.DecodeError: Unexpected end-group tag.
The script expect a protocol buffer file, I am not sure the script I am using to generate inference models is giving me proto buffer files or not.
Can someone please suggest what am I doing wrong, or is there a better way to achieve this. I simply want to convert checkpoint files generated by tensor to proto buffer.
Thanks
The link to the script you ran is broken, but in any case the recommended thing is not to try to generate an inference model from a checkpoint, but rather to embed code at the end of your training program that will emit a "SavedModel" export (which is not the same thing as a checkpoint).
Please see [1], and in particular the heading "Building a Saved Model". Note that a Saved Model constitutes multiple files, one of which is indeed a protocol buffer (which directly answers your question I hope); the others are variable files and (optional) asset files.
[1] https://www.tensorflow.org/programmers_guide/saved_model
I'm using SKlearn's Pipeline model to extract and construct a united feature which is then being sent to a random forest classifier, while some feature extractors can be removed or added later, consider the following structure:
model = Pipeline([
('feature_extract',
FeatureUnion([
('feature A', extracorA()),
('feature B', ExtractorB()),
('feature C', FeatureUnion([
('c1', C1Extractor())
('c2', C2Extractor())]))
)]),
('random_forest', RandomForestRegressor(...)))])
I would like to improve the predictions of the random forest by inspecting the
feature_importances_
property of the RandomForstRegressor
I managed to get the list using:
model._final_estimator.feature_importances_
And now I would like to dynamically link between the column number in the feature_importances_ index to the feature name/step in the pipeline.
Is there a preferred way to save/retrieve the feature name inside a feature union? How would you address this issue?
To keep everything in dynamic form, you can use the below function as the transform implementation of a separate class and make the class's object a part of your pipeline. You can even change scoring parameter. I think Grid Search as a part of the pipeline is what you are looking for...
def best_config(model, parameters, train_instances, judgements):
clf = GridSearchCV(model, parameters, cv=5,
scoring="accuracy", verbose=5, n_jobs=4)
clf.fit(train_instances, judgements)
best_estimator = clf.best_estimator_
return [str(clf.best_params_), clf.best_score_,
best_estimator]