Extract complex real components
Separate amplitudes from complex-valued numerical data.
NumPy · Pipe
ndarray.real
Returns the real part of an ndarray. It usually provides a view into the source array, while object arrays use each element’s .real value.
How it works
Accessing ndarray.real extracts the real component of every array element. For most numeric arrays it usually provides a view into the original array; object arrays instead obtain each element’s .real value individually.
Syntax
ndarray.realReturns
The real part of the array; usually a view for ordinary numeric arrays and elementwise .real values for object arrays.
Key points
- ndarray.real extracts the real component of an ndarray.
- For standard numeric arrays, the result generally shares the source array’s data through a view.
- Object-dtype arrays obtain each element’s real value individually.
- numpy.real is the documented function equivalent of the ndarray.real attribute.
Common mistakes
- The result is generally a view, but object-dtype arrays are handled element by element, so view-based assumptions do not apply.
Example: Read real components from a complex array
import numpy as np
x = np.sqrt([1 + 0j, 0 + 1j])
real_parts = x.real
print(real_parts)
# [1. 0.70710678]
print(real_parts.dtype)
# float64Extracts the real component of each complex array element.
When to use it
Analyze computed results
Inspect the real values produced by complex-valued NumPy expressions.
Convenient attribute access
Use the array’s real component without an explicit conversion function.
Interview questions
QWhat does ndarray.real provide?
ndarray.real is an attribute that returns the array’s real part. For a complex array, each value contributes its real component while preserving the array’s shape.
Follow-up: How does it behave for object arrays? It evaluates .real elementwise rather than using the usual view behavior.
QDoes ndarray.real copy the data?
For ordinary numeric arrays, ndarray.real usually returns a view into the original array rather than copying the data. This can make access efficient and means the result may share storage with the source.
Follow-up: What exception does the documentation identify? Object arrays return elementwise .real values instead of the usual view into the original array.
QHow is ndarray.real related to numpy.real?
The attribute is accessed as x.real, where x is an ndarray. It is useful for separating real components from complex-valued data without calling a separate function.
Follow-up: What equivalent function does NumPy document? numpy.real is the equivalent function.
Related
numpy.realndarray.imag