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from sklearn.manifold import TSNE |
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import matplotlib.pyplot as plt |
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import numpy as np |
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def TSNE_reduction(latent_points: np.ndarray, perplexity=30, learning_rate=20): |
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""" |
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:param latent_points: [ndarray] - an array of arrays that define the points of multiple objects in the latent space |
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:param perplexity: [int] - default perplexity = 30 " Perplexity balances the attention t-SNE gives to local and global aspects of the data. It is roughly a guess of the number of close neighbors each point has... a denser dataset ... requires higher perplexity value" Recommended: Perplexity(5-50) |
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:param learning_rate: [int] - default learning rate = 200 "If the learning rate is too high, the data may look like a ‘ball’ with any point approximately equidistant from its nearest neighbours. If the learning rate is too low, most points may look compressed in a dense cloud with few outliers." Recommended: learning_rate(10-1000) |
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:return: [tuple] - the output is the x and y coordinates for the reduced latent space, a title, and a TSNE embedding |
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""" |
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model = TSNE(n_components=2, random_state=0, perplexity=perplexity, |
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learning_rate=learning_rate) |
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embedding = model |
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tsne_data = model.fit_transform(latent_points) |
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x = tsne_data[:, 0] |
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y = tsne_data[:, 1] |
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title = ("T-SNE of Data") |
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return x, y, title, embedding |
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def plot_dimensionality_reduction(x: list, y: list, label_set: list, title: str): |
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""" |
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:param x: [list] - the first set of coordinates for each latent point |
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:param y: [list] - the second set of coordinates for each latent point |
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:param label_set: [list] - a set of values that define the color of each point based on an additional quantitative attribute. |
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:return: matplotlib figure - the output is a matplotlib figure that displays all the points in a 2-dimensional latent space, based on the labels provided. |
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""" |
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plt.title(title) |
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if label_set[0].dtype == float: |
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plt.scatter(x, y, c=label_set) |
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cbar = plt.colorbar() |
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cbar.set_label('Average Density', fontsize=12) |
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print("using scatter") |
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else: |
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for label in set(label_set): |
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cond = np.where(np.array(label_set) == str(label)) |
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plt.plot(x[cond], y[cond], marker='o', linestyle='none', label=label) |
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plt.legend(numpoints=1) |
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plt.xlabel("Dimension 1") |
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plt.ylabel("Dimension 2") |
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""" |
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# Use for personal plotting |
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import pandas as pd |
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import json |
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df = pd.read_csv('2D_Lattice.csv') |
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# row = 0 |
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# box = df.iloc[row,1] |
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# array = np.array(json.loads(box)) |
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# Select a subset of the data to use |
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number_samples = 10000 |
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perplexity = 300 |
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random_samples = sorted(np.random.randint(0,len(df), number_samples)) # Generates ordered samples |
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df = df.iloc[random_samples] |
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print(df) |
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print(np.shape(df)) |
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# For plotting CSV data |
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# define a function to flatten a box |
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def flatten_box(box_str): |
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box = json.loads(box_str) |
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return np.array(box).flatten() |
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# apply the flatten_box function to each row of the dataframe and create a list of flattened arrays |
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flattened_arrays = df['Array'].apply(flatten_box).tolist() |
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avg_density = np.sum(flattened_arrays, axis=1)/(len(flattened_arrays[0])) |
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x, y, title, embedding = TSNE_reduction(flattened_arrays, perplexity=perplexity) |
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plot_dimensionality_reduction(x, y, avg_density, title) |
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plt.title(title) |
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plt.savefig('TSNE_Partial_Factorial_Perplexity_' + str(perplexity) + "_Data_Samples_" + str(number_samples)) |
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""" |
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