def test_convert_to_scientific_form(input_number, decimal_places, threshold,
expected_output):
'''Test method converts to scientific form.'''
# Act, assert
actual_output = Collatz.convert_to_scientific_form(
input_number, decimal_places=decimal_places, threshold=threshold)
assert expected_output == actual_output
def plot_comparison(sequences, scale='linear'):
'''Plot each sequence in sequences on the same plot.'''
linear = scale == 'linear'
plt.style.use('ggplot')
plotted_sequences = 0
for sequence in sequences:
if len(sequence) == 1:
print(
f'Sequence {sequence!r} not plotted as only contains one element'
)
continue
x_values = range(len(sequence))
sequence_label = Collatz.convert_to_scientific_form(sequence[0])
try:
plt.plot(x_values, sequence, label=sequence_label)
plotted_sequences += 1
except OverflowError:
print(f'ERROR: Sequence {sequence!r} too large to plot')
continue
# Axis limits
plt.xlim(0)
y_min = 0 if linear else 1
plt.ylim(y_min)
# Labels
plt.title(f'Comparison plot of {plotted_sequences} Collatz sequences')
plt.xlabel('Step')
plt.ylabel(fr'Value - $\it{{{scale}\ scale}}$')
# Scale
scale = 'linear' if linear else 'log'
plt.yscale(scale)
if len(sequences) <= 10:
plt.legend(title='First term', facecolor='#fdf6e3', framealpha=1)
plt.show()
