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neural network

The neural network give a score for how at risk the child is to be trafficked. It trains on a dataset provided by the pool of social workers updating the db. Each time the user inputs data, the Flask app sends the data to Pandas to be preprocessed for the neural network. The social worker can predict any new client’s score.
It is written in Tensorflow, which can kind of be thought of as a more powerful version of Numpy, made so that we could build neural networks from computational graphs.
1
necessary imports:
2
import tensorflow as tf
import numpy as np
import pandas as pd
from tensorflow import keras
from tensorflow.keras import layers
3
load the data into a DataFrame, make training and test sets,
4
# pour the data into a frame
dataframe = pd.read_csv("/Users/vincentparis/dev/pca/mL/binarydata.csv")

# print(dataframe)
print(dataframe.shape)
print(dataframe.head())

# split training and testing dataframes
val_dataframe = dataframe.sample(frac=0.2, random_state=1337)
train_dataframe = dataframe.drop(val_dataframe.index)

print(
"Using %d samples for training and %d for validation"
% (len(train_dataframe), len(val_dataframe))
)

5
pop the target off (so the net can train) and make the dataset
6
# convert dfs to Dataset
def dataframe_to_dataset(dataframe):
dataframe = dataframe.copy()
# pop the target
labels = dataframe.pop("csec_risk")
ds = tf.data.Dataset.from_tensor_slices((dict(dataframe), labels))
ds = ds.shuffle(buffer_size=len(dataframe))
return ds

train_ds = dataframe_to_dataset(train_dataframe)
val_ds = dataframe_to_dataset(val_dataframe)

for x, y in train_ds.take(1):
print("Input:", x)
print("Target:", y)

train_ds = train_ds.batch(32)
val_ds = val_ds.batch(32)
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1
encode the numerical and categorical (all binary, in my case) features
2
def encode_numerical_feature(feature, name, dataset):
# Create a Normalization layer for our feature
normalizer = Normalization()

# Prepare a Dataset that only yields our feature
feature_ds = dataset.map(lambda x, y: x[name])
feature_ds = feature_ds.map(lambda x: tf.expand_dims(x, -1))

# Learn the statistics of the data
normalizer.adapt(feature_ds)

# Normalize the input feature
encoded_feature = normalizer(feature)
return encoded_feature

def encode_integer_categorical_feature(feature, name, dataset):
# Create a CategoryEncoding for our integer indices
encoder = CategoryEncoding(output_mode="binary")

# Prepare a Dataset that only yields our feature
feature_ds = dataset.map(lambda x, y: x[name])
feature_ds = feature_ds.map(lambda x: tf.expand_dims(x, -1))

# Learn the space of possible indices
encoder.adapt(feature_ds)

# Apply one-hot encoding to our indices
encoded_feature = encoder(feature)
return encoded_feature

# categorical features
sex = keras.Input(shape=(1,), name="sex", dtype="int64")
num_cases = keras.Input(shape=(1,), name="num_cases", dtype="int64")
zipcode = keras.Input(shape=(1,), name="zipcode", dtype="int64")
social_media = keras.Input(shape=(1,), name="social_media", dtype="int64")
basic_need = keras.Input(shape=(1,), name="basic_need", dtype="int64")
safetysish = keras.Input(shape=(1,), name="safetysish", dtype="int64")
runaway = keras.Input(shape=(1,), name="runaway", dtype="int64")
race = keras.Input(shape=(1,), name="race", dtype="int64")
caregiver_MH = keras.Input(shape=(1,), name="caregiver_MH", dtype="int64")
rem_home = keras.Input(shape=(1,), name="rem_home", dtype="int64")

# Numerical features
age = keras.Input(shape=(1,), name="age", dtype="int64")
aperp_age = keras.Input(shape=(1,), name="aperp_age", dtype="int64")
age_diff = keras.Input(shape=(1,), name="age_diff", dtype="int64")

all_inputs = [
age,
sex,
num_cases,
aperp_age,
age_diff,
zipcode,
social_media,
basic_need,
safetysish,
runaway,
race,
caregiver_MH,
rem_home
]

sex_encoded = encode_integer_categorical_feature(sex, "sex", train_ds)
numcase_encoded = encode_integer_categorical_feature(num_cases, "num_cases", train_ds)
zip_encoded = encode_integer_categorical_feature(zipcode, "zipcode", train_ds)
socmed_encoded = encode_integer_categorical_feature(social_media, "social_media", train_ds)
basicneed_encoded = encode_integer_categorical_feature(basic_need, "basic_need", train_ds)
safe_encoded = encode_integer_categorical_feature(safetysish, "safetysish", train_ds)
runaway_encoded = encode_integer_categorical_feature(runaway, "runaway", train_ds)
race_encoded = encode_integer_categorical_feature(race, "race", train_ds)
caremh_encoded = encode_integer_categorical_feature(caregiver_MH, "caregiver_MH", train_ds)
rem_encoded = encode_integer_categorical_feature(rem_home, "rem_home", train_ds)

# Numerical features
age_encoded = encode_numerical_feature(age, "age", train_ds)
aperpage_encoded = encode_numerical_feature(aperp_age, "aperp_age", train_ds)
agediff_encoded = encode_numerical_feature(age_diff, "age_diff", train_ds)

all_features = layers.concatenate(
[
sex_encoded,
numcase_encoded,
zip_encoded,
socmed_encoded,
basicneed_encoded,
safe_encoded,
runaway_encoded,
race_encoded,
caremh_encoded,
rem_encoded,
age_encoded,
aperpage_encoded,
agediff_encoded,
]
)

x = layers.Dense(32, activation="relu")(all_features)
x = layers.Dropout(0.5)(x)
output = layers.Dense(1, activation="sigmoid")(x)
model = keras.Model(all_inputs, output)
model.compile("adam", "binary_crossentropy", metrics=["accuracy"])

keras.utils.plot_model(model, show_shapes=True, rankdir="LR",
to_file='/Users/vincentparis/dev/pca/mL/model.png')

model.fit(train_ds, epochs=50, validation_data=val_ds)
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1
give it a sample dictionary, representing a new client, and run prediction
2
sample = {
"age": 13,
"sex": 0,
"num_cases": 2,
"aperp_age": 29,
"age_diff": 16,

"zipcode": 10,
"social_media": 1,

# should be a bunch of binary cols for basic needs
"basic_need": 1,
"safetysish": 0,
"runaway": 0,
"race": 0,
"caregiver_MH": 1,
"remhome": 1,
}

input_dict = {name: tf.convert_to_tensor([value]) for name, value in sample.items()}
# print(input_dict)
model.predict(input_dict)
3
>> [[0.4350972]]
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