replaces approximate real numbers in expr that are close to zero by the exact integer 0.


replaces numbers smaller in absolute magnitude than delta by 0.



open allclose all

Basic Examples  (1)

Zero out elements that are very close to 0:

Scope  (2)

Drop small imaginary parts:

Convert from approximate zeros to exact zeros:

Applications  (2)

Test if two numbers are the same to a certain tolerance:

They are the same to the default tolerance of :

They are not the same to the tolerance of :

Eliminate very small terms before comparing with Equal:

They are not equal because a small number is not equal to zero:

Once the small terms are eliminated, equality holds:

Properties & Relations  (1)

A functional implementation of Chop:

Chop is much faster for large expressions:

Possible Issues  (1)

Machine complex numbers have machine reals for both real and imaginary parts:

Consequently, Chop does not make the real part of machine complex numbers an exact zero:

Small imaginary parts from machine complex numbers are eliminated to make a machine real:

Wolfram Research (1988), Chop, Wolfram Language function,


Wolfram Research (1988), Chop, Wolfram Language function,


Wolfram Language. 1988. "Chop." Wolfram Language & System Documentation Center. Wolfram Research.


Wolfram Language. (1988). Chop. Wolfram Language & System Documentation Center. Retrieved from


@misc{reference.wolfram_2023_chop, author="Wolfram Research", title="{Chop}", year="1988", howpublished="\url{}", note=[Accessed: 28-September-2023 ]}


@online{reference.wolfram_2023_chop, organization={Wolfram Research}, title={Chop}, year={1988}, url={}, note=[Accessed: 28-September-2023 ]}