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# Python cmath.isclose() Method

### Example

Compare the closeness of two complex values:

#Import cmath Library
import cmath

#compare the closeness of two complex values using relative tolerance
print(cmath.isclose(10+5j, 10+5j))
print(cmath.isclose(10+5j, 10.01+5j))
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## Definition and Usage

The `cmath.isclose()` method checks whether two complex values are close, or not. This method returns a Boolean value: `True` if the values are close, otherwise `False`.

This method uses a relative tolerance, or an absolute tolerance, to see if the values are close.

Tip: It uses the following formula to compare the values:
abs(a-b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)

## Syntax

cmath.isclose(a, b, rel_tol = value, abs_tol = value)

## Parameter Values

Parameter Description
a Required. The first value to check for closeness
b Required. The second value to check for closeness
rel_tol = value Optional. The relative tolerance. It is the maximum allowed difference between value a and b. Default value is 1e-09
abs_tol = value Optional. The minimum absolute tolerance. It is used to compare values near 0. The value must be at least 0

## Technical Details

Return Value: A `bool` value. `True` if the values are close, otherwise `False` 3.5

## More Examples

### Example

Compare the closeness of two complex values where absolute tolerance is defined:

#Import cmath Library
import cmath

#compare the closeness of two complex values using absolute tolerance
print(cmath.isclose(10+5j, 10+5j, abs_tol=0.005))
print(cmath.isclose(10+5j, 10.01+5j, abs_tol=0.005))
Try it Yourself »