当前位置: 首页>>代码示例>>Python>>正文


Python Minimizer.penalty方法代码示例

本文整理汇总了Python中lmfit.Minimizer.penalty方法的典型用法代码示例。如果您正苦于以下问题:Python Minimizer.penalty方法的具体用法?Python Minimizer.penalty怎么用?Python Minimizer.penalty使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在lmfit.Minimizer的用法示例。


在下文中一共展示了Minimizer.penalty方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Python代码示例。

示例1: CommonMinimizerTest

# 需要导入模块: from lmfit import Minimizer [as 别名]
# 或者: from lmfit.Minimizer import penalty [as 别名]

#.........这里部分代码省略.........
        if not HAS_EMCEE:
            return True

        self.mini.emcee(nwalkers=100, steps=5)

        # if you've run the sampler the Minimizer object should have a _lastpos
        # attribute
        assert_(hasattr(self.mini, '_lastpos'))

        # now try and re-use sampler
        out2 = self.mini.emcee(steps=10, reuse_sampler=True)
        assert_(out2.chain.shape[1] == 15)

        # you shouldn't be able to reuse the sampler if nvarys has changed.
        self.mini.params['amp'].vary = False
        pytest.raises(ValueError, self.mini.emcee, reuse_sampler=True)

    def test_emcee_lnpost(self):
        # check ln likelihood is calculated correctly. It should be
        # -0.5 * chi**2.
        result = self.mini.minimize()

        # obtain the numeric values
        # note - in this example all the parameters are varied
        fvars = np.array([par.value for par in result.params.values()])

        # calculate the cost function with scaled values (parameters all have
        # lower and upper bounds.
        scaled_fvars = []
        for par, fvar in zip(result.params.values(), fvars):
            par.value = fvar
            scaled_fvars.append(par.setup_bounds())

        val = self.mini.penalty(np.array(scaled_fvars))

        # calculate the log-likelihood value
        bounds = np.array([(par.min, par.max)
                           for par in result.params.values()])
        val2 = _lnpost(fvars,
                       self.residual,
                       result.params,
                       result.var_names,
                       bounds,
                       userargs=(self.x, self.data))

        assert_almost_equal(-0.5 * val, val2)

    def test_emcee_output(self):
        # test mcmc output
        if not HAS_EMCEE:
            return True
        try:
            from pandas import DataFrame
        except ImportError:
            return True
        out = self.mini.emcee(nwalkers=10, steps=20, burn=5, thin=2)
        assert_(isinstance(out, MinimizerResult))
        assert_(isinstance(out.flatchain, DataFrame))

        # check that we can access the chains via parameter name
        assert_(out.flatchain['amp'].shape[0] == 80)
        assert out.errorbars
        assert_(np.isfinite(out.params['amp'].correl['period']))

        # the lnprob array should be the same as the chain size
        assert_(np.size(out.chain)//out.nvarys == np.size(out.lnprob))
开发者ID:lmfit,项目名称:lmfit-py,代码行数:70,代码来源:test_nose.py

示例2: CommonMinimizerTest

# 需要导入模块: from lmfit import Minimizer [as 别名]
# 或者: from lmfit.Minimizer import penalty [as 别名]

#.........这里部分代码省略.........

        # but you can't initialise if the shape is wrong.
        assert_raises(ValueError,
                      self.mini.emcee,
                      nwalkers=100,
                      steps=1,
                      pos=out.chain[..., -1, :-1])

    def test_emcee_reuse_sampler(self):
        if not HAS_EMCEE:
            return True

        self.mini.emcee(nwalkers=100, steps=5)

        # if you've run the sampler the Minimizer object should have a _lastpos
        # attribute
        assert_(hasattr(self.mini, '_lastpos'))

        # now try and re-use sampler
        out2 = self.mini.emcee(steps=10, reuse_sampler=True)
        assert_(out2.chain.shape[1] == 15)

        # you shouldn't be able to reuse the sampler if nvarys has changed.
        self.mini.params['amp'].vary = False
        assert_raises(ValueError, self.mini.emcee, reuse_sampler=True)

    def test_emcee_lnpost(self):
        # check ln likelihood is calculated correctly. It should be
        # -0.5 * chi**2.
        result = self.mini.minimize()

        # obtain the numeric values
        # note - in this example all the parameters are varied
        fvars = np.array([par.value for par in result.params.values()])

        # calculate the cost function with scaled values (parameters all have
        # lower and upper bounds.
        scaled_fvars = []
        for par, fvar in zip(result.params.values(), fvars):
            par.value = fvar
            scaled_fvars.append(par.setup_bounds())

        val = self.mini.penalty(np.array(scaled_fvars))

        # calculate the log-likelihood value
        bounds = np.array([(par.min, par.max)
                           for par in result.params.values()])
        val2 = _lnpost(fvars,
                       self.residual,
                       result.params,
                       result.var_names,
                       bounds,
                       userargs=(self.x, self.data))

        assert_almost_equal(-0.5 * val, val2)

    def test_emcee_output(self):
        # test mcmc output
        if not HAS_EMCEE:
            return True
        try:
            from pandas import DataFrame
        except ImportError:
            return True
        out = self.mini.emcee(nwalkers=10, steps=20, burn=5, thin=2)
        assert_(isinstance(out, MinimizerResult))
        assert_(isinstance(out.flatchain, DataFrame))

        # check that we can access the chains via parameter name
        assert_(out.flatchain['amp'].shape[0] == 80)
        assert_(out.errorbars is True)
        assert_(np.isfinite(out.params['amp'].correl['period']))

        # the lnprob array should be the same as the chain size
        assert_(np.size(out.chain)//4 == np.size(out.lnprob))

    @decorators.slow
    def test_emcee_float(self):
        # test that it works if the residuals returns a float, not a vector
        if not HAS_EMCEE:
            return True

        def resid(pars, x, data=None):
            return -0.5 * np.sum(self.residual(pars, x, data=data)**2)

        # just return chi2
        def resid2(pars, x, data=None):
            return np.sum(self.residual(pars, x, data=data)**2)

        self.mini.userfcn = resid
        np.random.seed(123456)
        out = self.mini.emcee(nwalkers=100, steps=200,
                                      burn=50, thin=10)
        check_paras(out.params, self.p_true, sig=3)

        self.mini.userfcn = resid2
        np.random.seed(123456)
        out = self.mini.emcee(nwalkers=100, steps=200,
                              burn=50, thin=10, float_behavior='chi2')
        check_paras(out.params, self.p_true, sig=3)
开发者ID:brennerd11,项目名称:lmfit-py,代码行数:104,代码来源:test_nose.py


注:本文中的lmfit.Minimizer.penalty方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。