Precision context

This module manage the context precision of calculations using affapy.

Indeed, you can choice the precision using the precision class. You can set different precision contexts between functions using the precision decorator or use the class using the with statement.

This class changes the precision context of mpmath.

You can see exPrecision1 and exPrecision2 to see how it works.

class precision.precision(dps: int = None, prec: int = None)

Bases: contextlib.ContextDecorator

Manage precision for affapy library. You can use it:

  • As decorator of a function

  • Using the with statement

It contains four fields:

  • dps: decimal precision (decimals number)

  • prec: binary precision (bits number)

  • old_dps: decimal precision before entry to the context

  • old_prec: binary precision before entry to the context

Example:

from affapy.precision import precision

with precision(dps=30):
    x + y

@precision(dps=30)
def eval_fct(x, y):
    return x + y
__init__(dps: int = None, prec: int = None)

Init the context manager for precision. You need to mention dps or prec. Both is useless.

Parameters

  • dps (int) – decimal precision of mpmath

  • prec (int) – binary precision of mpmath

Raises

affapyError – Invalid value for precision

property dps

Get decimal precision.

property prec

Get binary precision.

property old_dps

Get old decimal precision.

property old_prec

Get old binary precision.

static set_dps(dps: int)

Set decimal precision outside precision class.

Parameters

dps (int) – decimal precision

static set_prec(prec: int)

Set binary precision outside precision class.

Parameters

prec (int) – binary precision

__enter__()

Set the mpmath precision for a portion of code.

Raises

affapyError – No precision mentioned

__exit__(exc_type, exc_val, exc_tb)

Reset the mpmath precision to its last value.

Raises

affapyError – No precision saved