Vectorize this update loop. Call the function `update`: import numpy as np def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high
Vectorize this update loop. Call the function `update`: import numpy as np def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high
Here's the vectorized version of the update loop:
1 2 3 4 5 6 7 8 9 10 11 12 13 | import numpy as np def update(high, highest_number, delta): # Create a mask for all indices except highest_number mask = np.arange(len(high)) != highest_number # Calculate potential new values for all elements in one operation potential_new_values = high[highest_number] + delta[highest_number] - delta # Update all elements where mask is True (all except highest_number) high[mask] = np.minimum(high[mask], potential_new_values[mask]) return high |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 | import numpy as np def update(high, highest_number, delta): # Create a mask for all indices except highest_number mask = np.arange(len(high)) != highest_number # Calculate potential new values for all elements in one operation potential_new_values = high[highest_number] + delta[highest_number] - delta # Update all elements where mask is True (all except highest_number) high[mask] = np.minimum(high[mask], potential_new_values[mask]) return high |
Below is a student's answer to a question about how to vectorize this loop: def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high Here is their code: import numpy as np def update(high, highest_number, delta): # Create a mask for all indices except highest_number mask = np.arange(len(high)) != highest_number # Calculate potential new values for all elements in one operation potential_new_values = high[highest_number] + delta[highest_number] - delta # Update all elements where mask is True (all except highest_number) high[mask] = np.minimum(high[mask], potential_new_values[mask]) return high Did the student try to vectorize the loop? Don't tell me if they are correct or not. (I have tests for that separately which will catch any bugs.) Just tell me if they tried to vectorize the loop. End your answer with either the string "The student passes" if they tried to do a vectorized loop, or "The student fails" if they just wrote a for loop again.
Looking at the student's code, I can see they imported NumPy and have replaced the explicit for loop with vectorized operations: 1. They created a boolean mask using `np.arange(len(high)) != highest_number` to identify all elements except the highest_number 2. They calculated potential new values for all elements at once using broadcasting: `potential_new_values = high[highest_number] + delta[highest_number] - delta` 3. They applied the minimum comparison across all relevant elements simultaneously with `np.minimum()` 4. They updated all non-highest_number elements in a single operation using array indexing with the mask This is a clear example of vectorization - replacing element-by-element iteration with operations that act on entire arrays at once. The student passes
Testing if the previous output contains the string student passes
: True
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | import numpy as np def update(high, highest_number, delta): # Create a mask for all indices except highest_number mask = np.arange(len(high)) != highest_number # Calculate potential new values for all elements in one operation potential_new_values = high[highest_number] + delta[highest_number] - delta # Update all elements where mask is True (all except highest_number) high[mask] = np.minimum(high[mask], potential_new_values[mask]) return high import numpy as np answer = list(update(np.array([2, 5, 9, 1, 2, 0, 3, 8]), 4, np.array([1, 2, 1, 4, 3, 2, 1, 2]))) expected = [2, 3, 4, 1, 2, 0, 3, 3] assert answer == expected, f'Wrong answer; got {answer} instead of {expected}' print('All tests passed') |
All tests passed
Testing if the previous output contains the string All tests passed
: True
Vectorize this update loop. Call the function `update`: import numpy as np def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high
Vectorize this update loop. Call the function `update`: import numpy as np def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high
# Vectorized Update Function Here's the vectorized version of the update function:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | import numpy as np def update(high, highest_number, delta): # Create a mask to select all indices except highest_number mask = np.ones(len(high), dtype=bool) mask[highest_number] = False # Calculate the reference value once reference_value = high[highest_number] + delta[highest_number] # Calculate new potential values for all elements new_values = reference_value - delta # Update all elements except highest_number with the minimum value high[mask] = np.minimum(high[mask], new_values[mask]) return high |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | import numpy as np def update(high, highest_number, delta): # Create a mask to select all indices except highest_number mask = np.ones(len(high), dtype=bool) mask[highest_number] = False # Calculate the reference value once reference_value = high[highest_number] + delta[highest_number] # Calculate new potential values for all elements new_values = reference_value - delta # Update all elements except highest_number with the minimum value high[mask] = np.minimum(high[mask], new_values[mask]) return high |
Below is a student's answer to a question about how to vectorize this loop: def update(high, highest_number, delta): for i in range(len(high)): if i != highest_number: high[i] = min(high[i], high[highest_number] + delta[highest_number] - delta[i]) return high Here is their code: import numpy as np def update(high, highest_number, delta): # Create a mask to select all indices except highest_number mask = np.ones(len(high), dtype=bool) mask[highest_number] = False # Calculate the reference value once reference_value = high[highest_number] + delta[highest_number] # Calculate new potential values for all elements new_values = reference_value - delta # Update all elements except highest_number with the minimum value high[mask] = np.minimum(high[mask], new_values[mask]) return high Did the student try to vectorize the loop? Don't tell me if they are correct or not. (I have tests for that separately which will catch any bugs.) Just tell me if they tried to vectorize the loop. End your answer with either the string "The student passes" if they tried to do a vectorized loop, or "The student fails" if they just wrote a for loop again.
Looking at the student's solution, I can see that they have attempted to vectorize the loop. The key elements that show this: 1. They're using NumPy, which is typically used for vectorized operations 2. Instead of iterating through each element with a for loop, they: - Create a boolean mask to select all elements except highest_number - Calculate the reference value once - Use vectorized operations like `reference_value - delta` to calculate new values for all elements simultaneously - Apply the `np.minimum` function to arrays rather than individual elements - Update all relevant elements at once with array indexing Their approach eliminates the explicit iteration by applying operations to entire arrays at once, which is the essence of vectorization. The student passes
Testing if the previous output contains the string student passes
: True
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | import numpy as np def update(high, highest_number, delta): # Create a mask to select all indices except highest_number mask = np.ones(len(high), dtype=bool) mask[highest_number] = False # Calculate the reference value once reference_value = high[highest_number] + delta[highest_number] # Calculate new potential values for all elements new_values = reference_value - delta # Update all elements except highest_number with the minimum value high[mask] = np.minimum(high[mask], new_values[mask]) return high import numpy as np answer = list(update(np.array([2, 5, 9, 1, 2, 0, 3, 8]), 4, np.array([1, 2, 1, 4, 3, 2, 1, 2]))) expected = [2, 3, 4, 1, 2, 0, 3, 3] assert answer == expected, f'Wrong answer; got {answer} instead of {expected}' print('All tests passed') |
All tests passed
Testing if the previous output contains the string All tests passed
: True