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Python Dataset.sa["regressor"]方法代码示例

本文整理汇总了Python中mvpa.datasets.base.Dataset.sa["regressor"]方法的典型用法代码示例。如果您正苦于以下问题:Python Dataset.sa["regressor"]方法的具体用法?Python Dataset.sa["regressor"]怎么用?Python Dataset.sa["regressor"]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mvpa.datasets.base.Dataset的用法示例。


在下文中一共展示了Dataset.sa["regressor"]方法的1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: _call

# 需要导入模块: from mvpa.datasets.base import Dataset [as 别名]
# 或者: from mvpa.datasets.base.Dataset import sa["regressor"] [as 别名]
    def _call(self, dataset):
        # just for the beauty of it
        X = self._design

        # precompute transformation is not yet done
        if self._inv_design is None:
            self._inv_ip = (X.T * X).I
            self._inv_design = self._inv_ip * X.T

        # get parameter estimations for all features at once
        # (betas x features)
        betas = self._inv_design * dataset.samples

        # charge state
        self.ca.pe = pe = betas.T.A

        # if betas and no z-stats are desired return them right away
        if not self._voi == "pe" or self.ca.is_enabled("zstat"):
            # compute residuals
            residuals = X * betas
            residuals -= dataset.samples

            # estimates of the parameter variance and compute zstats
            # assumption of mean(E) == 0 and equal variance
            # XXX next lines ignore off-diagonal elements and hence covariance
            # between regressors. The humble being writing these lines asks the
            # god of statistics for forgives, because it knows not what it does
            diag_ip = np.diag(self._inv_ip)
            # (features x betas)
            beta_vars = np.array([r.var() * diag_ip for r in residuals.T])
            # (parameter x feature)
            zstat = pe / np.sqrt(beta_vars)

            # charge state
            self.ca.zstat = zstat

        if self._voi == "pe":
            # return as (beta x feature)
            result = Dataset(pe.T)
        elif self._voi == "zstat":
            # return as (zstat x feature)
            result = Dataset(zstat.T)
        else:
            # we shall never get to this point
            raise ValueError, "Unknown variable of interest '%s'" % str(self._voi)
        result.sa["regressor"] = np.arange(len(result))
        return result
开发者ID:arokem,项目名称:PyMVPA,代码行数:49,代码来源:glm.py


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