ó ›ßÈ[c @ s÷dZddlmZmZddlZddlmZddlm Z ddl m Z d d d d d ddddddg Z dd„Zedd„Zeje ƒd e fd„ƒYƒZd efd„ƒYZd efd„ƒYZd efd„ƒYZd efd„ƒYZdefd„ƒYZdefd„ƒYZdefd„ƒYZdefd „ƒYZdefd!„ƒYZdefd"„ƒYZdefd#„ƒYZd$efd%„ƒYZdefd&„ƒYZd'efd(„ƒYZ dS()s€ Classes that deal with stretching, i.e. mapping a range of [0:1] values onto another set of [0:1] values with a transformation iÿÿÿÿ(tdivisiontprint_functionNi(tsix(tInheritDocstringsi(t BaseTransformt BaseStretcht LinearStretcht SqrtStretcht PowerStretchtPowerDistStretchtSquaredStretcht LogStretcht AsinhStretcht SinhStretcht HistEqStretchtContrastBiasStretchcC s`|dkr&tj|ƒtj|ƒStj|d|ƒtj|tj|ƒd|ƒ|SdS(sCalculate the log base n of x.toutN(tNonetnptlogt true_divide(tntxR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyt_logns  cC sV|rtj|ddd|ƒS|dkr>tj|dtƒStj|ƒ|(|SdS(s“ Prepare the data by optionally clipping and copying, and return the array that should be subsequently used for in-place calculations. ggð?RtcopyN(RtclipRtarraytTruetasarray(tvaluesRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyt_prepare!s  cB s,eZdZedd„Zed„ƒZRS(s´ Base class for the stretch classes, which, when called with an array of values in the range [0:1], return an transformed array of values, also in the range [0:1]. cC sdS(su Transform values using this stretch. Parameters ---------- values : array-like The input values, which should already be normalized to the [0:1] range. clip : bool, optional If `True` (default), values outside the [0:1] range are clipped to the [0:1] range. out : `~numpy.ndarray`, optional If specified, the output values will be placed in this array (typically used for in-place calculations). Returns ------- result : `~numpy.ndarray` The transformed values. N((tselfRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyt__call__9scC sdS(s5A stretch object that performs the inverse operation.N((R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pytinverseOsN(t__name__t __module__t__doc__RRR tpropertyR!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR1scB s,eZdZedd„Zed„ƒZRS(sV A linear stretch. The stretch is given by: .. math:: y = x cC st|d|d|ƒS(NRR(R(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ^scC stƒS(s5A stretch object that performs the inverse operation.(R(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!asN(R"R#R$RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyRTscB s,eZdZedd„Zed„ƒZRS(sb A square root stretch. The stretch is given by: .. math:: y = \sqrt{x} cC s/t|d|d|ƒ}tj|d|ƒ|S(NRR(RRtsqrt(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR qscC s tdƒS(s5A stretch object that performs the inverse operation.i(R(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!vsN(R"R#R$RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyRgscB s5eZdZd„Zedd„Zed„ƒZRS(sµ A power stretch. The stretch is given by: .. math:: y = x^a Parameters ---------- a : float The power index (see the above formula). cC s tt|ƒjƒ||_dS(N(tsuperRt__init__tpower(Rta((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(‹scC s5t|d|d|ƒ}tj||jd|ƒ|S(NRR(RRR)(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR scC std|jƒS(s5A stretch object that performs the inverse operation.gð?(RR)(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!”sN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR|s  cB s8eZdZdd„Zedd„Zed„ƒZRS(s An alternative power stretch. The stretch is given by: .. math:: y = \frac{a^x - 1}{a - 1} Parameters ---------- a : float, optional The ``a`` parameter used in the above formula. Default is 1000. ``a`` cannot be set to 1. g@@cC s;|dkrtdƒ‚ntt|ƒjƒ||_dS(Nisa cannot be set to 1(t ValueErrorR'R R(texp(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(ªs cC sht|d|d|ƒ}tj|j|d|ƒtj|dd|ƒtj||jdd|ƒ|S(NRRigð?(RRR)R,tsubtractR(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR °s cC std|jƒS(s5A stretch object that performs the inverse operation.R*(tInvertedPowerDistStretchR,(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!·sN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR šs R.cB s8eZdZdd„Zedd„Zed„ƒZRS(sO Inverse transformation for `~astropy.image.scaling.PowerDistStretch`. The stretch is given by: .. math:: y = \frac{\log(y (a-1) + 1)}{\log a} Parameters ---------- a : float, optional The ``a`` parameter used in the above formula. Default is 1000. ``a`` cannot be set to 1. g@@cC s;|dkrtdƒ‚ntt|ƒjƒ||_dS(Nisa cannot be set to 1(R+R'R.R(R,(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(Îs cC set|d|d|ƒ}tj||jdd|ƒtj|dd|ƒt|j|d|ƒ|S(NRRgð?i(RRtmultiplyR,taddR(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR Ôs cC std|jƒS(s5A stretch object that performs the inverse operation.R*(R R,(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!ÛsN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR.½s cB s&eZdZd„Zed„ƒZRS(st A convenience class for a power stretch of 2. The stretch is given by: .. math:: y = x^2 cC stt|ƒjdƒdS(Ni(R'R R((R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(ëscC stƒS(s5A stretch object that performs the inverse operation.(R(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!îs(R"R#R$R(R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ás cB s8eZdZdd„Zedd„Zed„ƒZRS(sî A log stretch. The stretch is given by: .. math:: y = \frac{\log{(a x + 1)}}{\log{(a + 1)}}. Parameters ---------- a : float The ``a`` parameter used in the above formula. Default is 1000. g@@cC s tt|ƒjƒ||_dS(N(R'R R(R,(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(scC s„t|d|d|ƒ}tj||jd|ƒtj|dd|ƒtj|d|ƒtj|tj|jdƒd|ƒ|S(NRRgð?(RRR/R,R0RR(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR s &cC s t|jƒS(s5A stretch object that performs the inverse operation.(tInvertedLogStretchR,(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!sN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ôs  R1cB s5eZdZd„Zedd„Zed„ƒZRS(s Inverse transformation for `~astropy.image.scaling.LogStretch`. The stretch is given by: .. math:: y = \frac{e^{y} (a + 1) -1}{a} Parameters ---------- a : float, optional The ``a`` parameter used in the above formula. Default is 1000. cC s tt|ƒjƒ||_dS(N(R'R1R(R,(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR($scC s„t|d|d|ƒ}tj|tj|jdƒd|ƒtj|d|ƒtj|dd|ƒtj||jd|ƒ|S(NRRgð?(RRR/RR,R-R(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR (s &cC s t|jƒS(s5A stretch object that performs the inverse operation.(R R,(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!0sN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR1s  cB s8eZdZdd„Zedd„Zed„ƒZRS(sß An asinh stretch. The stretch is given by: .. math:: y = \frac{{\rm asinh}(x / a)}{{\rm asinh}(1 / a)}. Parameters ---------- a : float, optional The ``a`` parameter used in the above formula. The value of this parameter is where the asinh curve transitions from linear to logarithmic behavior, expressed as a fraction of the normalized image. Must be in the range between 0 and 1. Default is 0.1 gš™™™™™¹?cC s tt|ƒjƒ||_dS(N(R'R R(R*(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(IscC snt|d|d|ƒ}tj||jd|ƒtj|d|ƒtj|tjd|jƒd|ƒ|S(NRRgð?(RRRR*tarcsinh(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR Ms &cC s!tddtjd|jƒƒS(s5A stretch object that performs the inverse operation.R*gð?(R RR2R*(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!TsN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR 6s cB s8eZdZdd„Zedd„Zed„ƒZRS(sý A sinh stretch. The stretch is given by: .. math:: y = \frac{{\rm sinh}(x / a)}{{\rm sinh}(1 / a)} Parameters ---------- a : float, optional The ``a`` parameter used in the above formula. Default is 1/3. gð?g@cC s tt|ƒjƒ||_dS(N(R'R R(R*(RR*((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(iscC snt|d|d|ƒ}tj||jd|ƒtj|d|ƒtj|tjd|jƒd|ƒ|S(NRRgð?(RRRR*tsinh(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ms &cC s!tddtjd|jƒƒS(s5A stretch object that performs the inverse operation.R*gð?(R RR3R*(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!tsgUUUUUUÕ?N( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR Zs  cB s8eZdZdd„Zedd„Zed„ƒZRS(s  A histogram equalization stretch. Parameters ---------- data : array-like The data defining the equalization. values : array-like, optional The input image values, which should already be normalized to the [0:1] range. cC s‹tj|jƒƒ|_|jjƒ}|jjƒ}|j||||_|dkr~tjddt|jƒƒ|_ n ||_ dS(Nggð?( RtsorttraveltdatatmintmaxRtlinspacetlenR(RR6Rtvmintvmax((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(‡s $cC s8t|d|d|ƒ}tj||j|jƒ|(|S(NRR(RRtinterpR6R(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR •scC st|jd|jƒS(s5A stretch object that performs the inverse operation.R(tInvertedHistEqStretchR6R(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!šsN( R"R#R$RR(RR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyRzs  R>cB s8eZdZdd„Zedd„Zed„ƒZRS(s. Inverse transformation for `~astropy.image.scaling.HistEqStretch`. Parameters ---------- data : array-like The data defining the equalization. values : array-like, optional The input image values, which should already be normalized to the [0:1] range. cC sF||_|dkr9tjddt|jƒƒ|_n ||_dS(Nggð?(R6RRR9R:R(RR6R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(­s  $cC s8t|d|d|ƒ}tj||j|jƒ|(|S(NRR(RRR=RR6(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ´scC st|jd|jƒS(s5A stretch object that performs the inverse operation.R(RR6R(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!¹sN( R"R#R$RR(RR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR> s  cB s5eZdZd„Zedd„Zed„ƒZRS(sŒ A stretch that takes into account contrast and bias. The stretch is given by: .. math:: y = (x - {\rm bias}) * {\rm contrast} + 0.5 and the output values are clipped to the [0:1] range. Parameters ---------- contrast : float The contrast parameter (see the above formula). bias : float The bias parameter (see the above formula). cC s)tt|ƒjƒ||_||_dS(N(R'RR(tcontrasttbias(RR?R@((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(Ós cC s†t|dtd|ƒ}tj||jd|ƒtj||jd|ƒtj|dd|ƒ|r‚tj|ddd|ƒn|S(NRRgà?ii( RtFalseRR-R@R/R?R0R(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR ØscC st|j|jƒS(s5A stretch object that performs the inverse operation.(tInvertedContrastBiasStretchR?R@(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR!æsN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR¿s RBcB s5eZdZd„Zedd„Zed„ƒZRS(s1 Inverse transformation for ContrastBiasStretch. Parameters ---------- contrast : float The contrast parameter (see `~astropy.visualization.ConstrastBiasStretch). bias : float The bias parameter (see `~astropy.visualization.ConstrastBiasStretch). cC s)tt|ƒjƒ||_||_dS(N(R'RBR(R?R@(RR?R@((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR(ûs cC s†t|dtd|ƒ}tj|dd|ƒtj||jd|ƒtj||jd|ƒ|r‚tj|ddd|ƒn|S(NRRgà?ii( RRARR-RR?R0R@R(RRRR((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR scC st|j|jƒS(s5A stretch object that performs the inverse operation.(RR?R@(R((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyR! sN( R"R#R$R(RRR R%R!(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyRBìs   (!R$t __future__RRtnumpyRtexternRt utils.miscRt transformRt__all__RRRRt add_metaclassRRRRR R.R R R1R R RR>RRB(((s<lib/python2.7/site-packages/astropy/visualization/stretch.pyts4    "#$!!$ &-