在极坐标中应用np.expm1

Question

如何将pandas函数重写为polars？ 我对 np.expm1 有一些问题，在极坐标中没有这样的功能。

def add_elasticity_predictions(data: pd.DataFrame) -> pd.DataFrame:
    data["huber_elasticity"] = np.expm1(data["intercept"] + data["huber_elasticity_coefficient"] *
 np.log1p(data["discount_price"]))
    return data

例如

import polars as pl

data = pl.DataFrame({"elasticity_intercept": [-6.195475, -8.437139, -4.741667],
                     "elasticity_coefficient": [1.553659, 2.048057, 1.285653],
                     "discount_price": [126, 129, 115],
                    })

输出应为 [2.78384188, 3.62672375, 2.93456563]

Answer 1

来自 https://github.com/pola-rs/polars/issues/12891#issuecomment-1841872969：

numpy 函数https://numpy.org/doc/stable/reference/ generated/numpy.expm1.html#numpy.expm1

是一个ufunc，所以你可以直接使用它例如

df.with_columns(np.expm1(pl.col('values')))