NumPy np.sign(): Map Negative, Zero, and Positive Values
Use NumPy np.sign() to classify scalar or array values by sign, preserve array shape, handle NaN values, and understand complex-number behavior.
Numpy
Learn NumPy with array operations, random sampling, math functions, shapes, dtypes, plotting examples, and fixes for common NumPy errors.
NumPy argmin(): Index of the Minimum Along an Axis
Use NumPy argmin to find minimum indices, choose axes, preserve dimensions with keepdims, handle ties, and convert flat indices safely.
NumPy logical_and(): Elementwise Masks, Broadcasting, and Reductions
Use NumPy logical_and() for elementwise Boolean masks, broadcasting, range filters, where conditions, and logical reductions.
NumPy Random Poisson: Generate Counts and Validate Lambda
Generate Poisson-distributed counts with NumPy, choose lambda correctly, set a reproducible generator, and understand shape, mean, and variance expectations.
NumPy searchsorted: Find Insertion Indices in Sorted Arrays
Use NumPy searchsorted with sorted arrays, left and right sides, vectorized values, sorter indexes, and duplicate handling.
NumPy recarray: Structured Records and Field Access
Use NumPy recarray for structured records with named fields, understand attribute access limitations, filter and sort safely, and know when a structured array or DataFrame is better.
NumPy piecewise: Conditional Array Values
Evaluate different constants or functions over NumPy array regions with piecewise, matching condition shapes and optional defaults.
NumPy ifft: Inverse FFT, Axes, Scaling, and Complex Signals
Use NumPy ifft and ifftn to reconstruct signals from frequency data, with correct axes, normalization, complex values, padding, and verification.
NumPy ix_(): Open Mesh Indexing for Rows and Columns
Use NumPy ix_() to combine row and column selections into an open mesh and extract the rectangular submatrix they define.
NumPy heaviside(): Step Functions, Zero Values, and Arrays
Use NumPy heaviside() for step functions, including negative, zero, and positive inputs, the second zero-value argument, broadcasting, and plotting.