Replacing small values by zero

### 9.4.1 Replacing small values by zero

The epsilon2zero command replaces values close enough to zero by 0.

- epsilon2zero takes expr, an expression in x.
- epsilon2zero(expr) returns expr where any values of modulus less than epsilon (see Section 2.5.7, item 2.5.7, by default epsilon=1e−12) are replaced by zero. The expression is not evaluated.

#### Examples

With epsilon=1e−12 in the CAS configuration:

epsilon2zero(1e-13+x)

0+x |  |  |  |  |  |  |  |  |  |

With epsilon=1e−12:

epsilon2zero((1e-13+x)*100000)

100000 | ⎛ ⎝ | 0+x | ⎞ ⎠

With epsilon=0.0001:

epsilon2zero(0.001+x)

0.001+x |  |  |  |  |  |  |  |  |  |