Which library is designed for fast mathematical computations and array operations in data science?

The library designed specifically for fast mathematical computations and array operations in data science is NumPy. It provides support for large, multi-dimensional arrays and matrices, along with a collection of mathematical functions to operate on these arrays. NumPy's core functionality allows for efficient computation by leveraging optimized implementations written in C and Fortran, making it much faster than using Python's built-in lists for numerical tasks.

NumPy is fundamental in the scientific Python ecosystem and serves as the foundation for many other libraries, enabling functionalities that are essential for data science, like linear algebra, Fourier transforms, and random number generation. It allows users to perform element-wise operations, broadcasting, and operations on entire arrays, which are key features for handling large datasets efficiently.

In contrast, while Pandas is excellent for data manipulation and analysis, it is more focused on labeled data and does not provide the same level of performance for numerical computations as NumPy. Scikit-learn is primarily a machine learning library, offering tools for classification, regression, and clustering, but it builds on NumPy for data handling. Matplotlib, on the other hand, is used for data visualization and does not focus on mathematical computations or array operations.