ó ¡¼™\c@ sðdZddlmZddlmZmZmZmZdgZddl m Z m Z m Z ddlm Z mZmZe jeeƒZejededeed ƒZejeeededƒZde fd „ƒYZd S( s **Contains** * Medium iÿÿÿÿ(tdivision(tsecondtmetertkilogramtamperetMedium(tSymboltsympifytsqrt(tspeed_of_lighttu0te0iiicB s˜eZdZd d d d„Zed„ƒZed„ƒZed„ƒZed„ƒZ ed„ƒZ d„Z d„Z d „Z d „Zd „ZRS( s6 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] https://en.wikipedia.org/wiki/Optical_medium cC s|tt|ƒj||ƒ}t|ƒ|_t|ƒ|_t|ƒ|_|dk r|dk r‹|dkr‹|dtd|j|_n|dk rÂ|dkrÂ|dtd|j|_n|dk rx|dk rxt |tt |j|jƒƒdkrt dƒ‚qqxn_|dk rK|dk rKtt ||ƒ|_n-|dkrx|dkrxt |_t |_n|S(Nigíµ ÷Æ°>sValues are not consistent.(tsuperRt__new__Rt _permittivityt _permeabilityt_ntNonetctabsRt ValueErrort_e0mksat_u0mksa(tclstnamet permittivityt permeabilitytntobj((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyR Ds$ *  cC st|j|jƒS(sz 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) (RRR(tself((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pytintrinsic_impedanceXscC sE|jdk r6|jdk r6dt|j|jƒSt|jSdS(sM 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 >>> m2 = Medium('m2', n=1) >>> m.speed == m2.speed True iN(RRRRRR(R((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pytspeedoscC s t|jS(s× Returns refractive index of the medium. Examples ======== >>> from sympy.physics.optics import Medium >>> m = Medium('m') >>> m.refractive_index 1 (RR(R((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pytrefractive_index…scC s|jS(s 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((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyR•scC s|jS(s 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((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyR¥scC s=ddlm}t|ƒjd||j|j|jgƒS(Niÿÿÿÿ(tsstrs: (tsympy.printingR!ttypet__name__RRR(RR!((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyt__str__µscC s|j|jkS(sC Compares based on refractive index of the medium. (R (Rtother((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyt__lt__ºscC s ||k S(N((RR&((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyt__gt__ÀscC s|j|jkS(N(R (RR&((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyt__eq__ÃscC s ||k S(N((RR&((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyt__ne__ÆsN(R$t __module__t__doc__RR tpropertyRRR RRR%R'R(R)R*(((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyRs-    N(R,t __future__Rtsympy.physics.unitsRRRRt__all__tsympyRRRR R R t convert_toRRRR(((s:lib/python2.7/site-packages/sympy/physics/optics/medium.pyts" '#