Source code for Geometry3D.utils.constant

"""
Constant module

EPS and significant numbers for comparing float point numbers.

Two float numbers are deemed equal if they equal with each other within significant numbers.

Significant numbers = log(1 / eps) all the time
"""
from math import pi,log10

# epsilon to compare if two float numbers equal to each other

SIG_FIGURES = 10
FLOAT_EPS = 1 / (10 ** SIG_FIGURES)

[docs]def set_eps(eps = 1e-10):
    """
    **Input:**

    - eps: floating number with 1e-10 the default

    **Output:**
    
    No output but set EPS to eps
    
    Signigicant numbers is also changed.
    """
    global FLOAT_EPS,SIG_FIGURES
    FLOAT_EPS = eps
    SIG_FIGURES = round(log10(1 / eps))

[docs]def get_eps():
    '''
    **Input:**

    no input

    **Output:**
    
    - current eps: float
    '''
    global FLOAT_EPS
    return FLOAT_EPS

[docs]def get_sig_figures():
    '''
    **Input:**
    
    no input

    **Output:**
    
    - current significant numbers: int
    '''
    global SIG_FIGURES
    return SIG_FIGURES

[docs]def set_sig_figures(sig_figures = 10):
    '''
    **Input:**
    
    - sig_figures: int with 10 the default

    **Output:**
    
    No output but set signigicant numbers to sig_figures
    
    EPS is also changed.
    '''
    global FLOAT_EPS,SIG_FIGURES
    SIG_FIGURES = sig_figures
    FLOAT_EPS = 1 / (10 ** SIG_FIGURES)

SMALL_ANGLE = 0.1 # used in ..calc.aux_calc

__all__=('SIG_FIGURES','FLOAT_EPS','SMALL_ANGLE','set_eps','get_eps','get_sig_figures','set_sig_figures')