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Solutions-Coursera-Machine-…/Exercise3/utils.py
2018-08-26 09:57:20 -07:00

105 lines
3.2 KiB
Python
Executable File

import sys
import numpy as np
from matplotlib import pyplot
sys.path.append('..')
from submission import SubmissionBase
def displayData(X, example_width=None, figsize=(10, 10)):
"""
Displays 2D data stored in X in a nice grid.
"""
# Compute rows, cols
if X.ndim == 2:
m, n = X.shape
elif X.ndim == 1:
n = X.size
m = 1
X = X[None] # Promote to a 2 dimensional array
else:
raise IndexError('Input X should be 1 or 2 dimensional.')
example_width = example_width or int(np.round(np.sqrt(n)))
example_height = n / example_width
# Compute number of items to display
display_rows = int(np.floor(np.sqrt(m)))
display_cols = int(np.ceil(m / display_rows))
fig, ax_array = pyplot.subplots(display_rows, display_cols, figsize=figsize)
fig.subplots_adjust(wspace=0.025, hspace=0.025)
ax_array = [ax_array] if m == 1 else ax_array.ravel()
for i, ax in enumerate(ax_array):
ax.imshow(X[i].reshape(example_width, example_width, order='F'),
cmap='Greys', extent=[0, 1, 0, 1])
ax.axis('off')
def sigmoid(z):
"""
Computes the sigmoid of z.
"""
return 1.0 / (1.0 + np.exp(-z))
class Grader(SubmissionBase):
# Random Test Cases
X = np.stack([np.ones(20),
np.exp(1) * np.sin(np.arange(1, 21)),
np.exp(0.5) * np.cos(np.arange(1, 21))], axis=1)
y = (np.sin(X[:, 0] + X[:, 1]) > 0).astype(float)
Xm = np.array([[-1, -1],
[-1, -2],
[-2, -1],
[-2, -2],
[1, 1],
[1, 2],
[2, 1],
[2, 2],
[-1, 1],
[-1, 2],
[-2, 1],
[-2, 2],
[1, -1],
[1, -2],
[-2, -1],
[-2, -2]])
ym = np.array([0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3])
t1 = np.sin(np.reshape(np.arange(1, 25, 2), (4, 3), order='F'))
t2 = np.cos(np.reshape(np.arange(1, 41, 2), (4, 5), order='F'))
def __init__(self):
part_names = ['Regularized Logistic Regression',
'One-vs-All Classifier Training',
'One-vs-All Classifier Prediction',
'Neural Network Prediction Function']
super().__init__('multi-class-classification-and-neural-networks', part_names)
def __iter__(self):
for part_id in range(1, 5):
try:
func = self.functions[part_id]
# Each part has different expected arguments/different function
if part_id == 1:
res = func(np.array([0.25, 0.5, -0.5]), self.X, self.y, 0.1)
res = np.hstack(res).tolist()
elif part_id == 2:
res = func(self.Xm, self.ym, 4, 0.1)
elif part_id == 3:
res = func(self.t1, self.Xm) + 1
elif part_id == 4:
res = func(self.t1, self.t2, self.Xm) + 1
else:
raise KeyError
yield part_id, res
except KeyError:
yield part_id, 0