B [j@sdZddlmZddlmZmZmZmZdgZddl m Z m Z m Z ddlm Z mZmZe eeZeededeed ZeeeededZGd dde Zd S) z **Contains** * Medium )division)secondmeterkilogramampereMedium)Symbolsympifysqrt)speed_of_lightu0e0cseZdZdZdfdd ZeddZeddZed d Zed d Z ed dZ ddZ ddZ ddZ ddZddZZS)ra5 This class represents an optical medium. The prime reason to implement this is to facilitate refraction, Fermat's principle, etc. An optical medium is a material through which electromagnetic waves propagate. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. Parameters ========== name: string The display name of the Medium. permittivity: Sympifyable Electric permittivity of the space. permeability: Sympifyable Magnetic permeability of the space. n: Sympifyable Index of refraction of the medium. Examples ======== >>> from sympy.abc import epsilon, mu >>> from sympy.physics.optics import Medium >>> m1 = Medium('m1') >>> m2 = Medium('m2', epsilon, mu) >>> m1.intrinsic_impedance 149896229*pi*kilogram*meter**2/(1250000*ampere**2*second**3) >>> m2.refractive_index 299792458*meter*sqrt(epsilon*mu)/second References ========== .. [1] http://en.wikipedia.org/wiki/Optical_medium Ncs tt|||}t||_t||_t||_|dk r|dkr`|dkr`|dtd|j|_|dkr|dkr|dtd|j|_|dkr|dkrt|tt |j|jdkrt dnD|dk r|dk rtt |||_n |dkr|dkrt |_t |_|S)Nrgư>zValues are not consistent.) superr__new__r _permittivity _permeabilityZ_ncabsr ValueError_e0mksa_u0mksa)clsname permittivity permeabilitynobj) __class__:lib/python3.7/site-packages/sympy/physics/optics/medium.pyrDs$     zMedium.__new__cCst|j|jS)az Returns intrinsic impedance of the medium. The intrinsic impedance of a medium is the ratio of the transverse components of the electric and magnetic fields of the electromagnetic wave travelling in the medium. In a region with no electrical conductivity it simplifies to the square root of ratio of magnetic permeability to electric permittivity. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.intrinsic_impedance 149896229*pi*kilogram*meter**2/(1250000*ampere**2*second**3) )r rr)selfr!r!r"intrinsic_impedanceXszMedium.intrinsic_impedancecCsdt|j|jS)z Returns speed of the electromagnetic wave travelling in the medium. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.speed 299792458*meter/second )r rr)r#r!r!r"speedosz Medium.speedcCs t|jS)z Returns refractive index of the medium. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.refractive_index 1 )rr&)r#r!r!r"refractive_indexszMedium.refractive_indexcCs|jS)a Returns electric permittivity of the medium. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.permittivity 625000*ampere**2*second**4/(22468879468420441*pi*kilogram*meter**3) )r)r#r!r!r"rszMedium.permittivitycCs|jS)a Returns magnetic permeability of the medium. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.permeability pi*kilogram*meter/(2500000*ampere**2*second**2) )r)r#r!r!r"rszMedium.permeabilitycCs ddlm}t|j||jS)Nr)sstr)Zsympy.printingr(type__name__args)r#r(r!r!r"__str__s zMedium.__str__cCs |j|jkS)zC Compares based on refractive index of the medium. )r')r#otherr!r!r"__lt__sz Medium.__lt__cCs ||k S)Nr!)r#r-r!r!r"__gt__sz Medium.__gt__cCs |j|jkS)N)r')r#r-r!r!r"__eq__sz Medium.__eq__cCs ||k S)Nr!)r#r-r!r!r"__ne__sz Medium.__ne__)NNN)r* __module__ __qualname____doc__rpropertyr$r&r'rrr,r.r/r0r1 __classcell__r!r!)r r"rs-     N)r4Z __future__rZsympy.physics.unitsrrrr__all__Zsympyrr r r r r Z convert_torrrrr!r!r!r"s "