NumPy: Create a vector with values from 0 to 20 and change the sign of the numbers in the range from 9 to 15
NumPy: Basic Exercise-22 with Solution
Write a NumPy program to create a vector with values from 0 to 20 and change the sign of the numbers in the range from 9 to 15.
Sample Solution :
Python Code :
import numpy as np
x = np.arange(21)
print("Original vector:")
print(x)
print("After changing the sign of the numbers in the range from 9 to 15:")
x[(x >= 9) & (x <= 15)] *= -1
print(x)
Sample Output:
Original vector: [ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20] After changing the sign of the numbers in the range from 9 to 15: [ 0 1 2 3 4 5 6 7 8 -9 -10 -11 -12 -13 -14 -15 16 17 18 19 20]
Pictorial Presentation:
Python-Numpy Code Editor:
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Find current directory and file's directory:
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To get the current working directory use
import os cwd = os.getcwd()
Documentation references for the modules, constants and functions used above:
- The os and os.path modules.
- The __file__ constant
- os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
- os.path.dirname(path) (returns "the directory name of pathname path")
- os.getcwd() (returns "a string representing the current working directory")
- os.chdir(path) ("change the current working directory to path")
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