diff --git a/crypto_features/feature/engineering.py b/crypto_features/feature/engineering.py
new file mode 100644
index 0000000..8bcffb2
--- /dev/null
+++ b/crypto_features/feature/engineering.py
@@ -0,0 +1,241 @@
+"""
+Feature engineering module
+"""
+import matplotlib.pyplot as plt
+import numpy as np
+import pandas as pd
+
+from crypto_features.feature.information_correlation import \
+    InformationCorrelation
+
+
+class FeatureEngineering:
+    def __init__(self, feature: pd.Series, klines=None):
+        """
+
+        :param feature: feature data
+        :param klines: klines data
+        """
+        self._feature = feature
+        self._klines = klines
+
+    def set_feature(self, feature: pd.Series):
+        """
+        Set feature data
+        """
+        self._feature = feature
+
+    def set_klines(self, klines: pd.DataFrame):
+        """
+        Set return data
+        """
+        self._klines = klines
+
+    def _make_return(self, minutes: int) -> pd.Series:
+        """
+        Make return data
+
+        :param minutes: minutes to calculate return
+        """
+        return self._klines["close"].pct_change(minutes)
+
+    def visualize_histogram(self, return_minutes: int):
+        """
+        Visualize histogram of funding rate
+
+        :param return_minutes: minutes to calculate return
+        """
+        # plot settings
+        fig = plt.figure(figsize=(8, 8))
+        grid = plt.GridSpec(5, 4, hspace=0.5, wspace=0.5)
+
+        x, y = InformationCorrelation.format_array(
+            self._klines, self._feature, return_minutes
+        )
+        main_ax = fig.add_subplot(grid[1:, 1:])
+        main_ax.scatter(x, y, alpha=0.5)
+        main_ax.set_xlabel("feature")
+        main_ax.tick_params(left=True, bottom=True, labelleft=True, labelbottom=True)
+
+        x_hist = fig.add_subplot(grid[0, 1:], sharex=main_ax)
+        x_hist.hist(x, bins=50, align="mid", rwidth=0.8)
+        x_hist.set_title("feature vs return")
+        x_hist.tick_params(bottom=True, labelbottom=True)
+
+        y_hist = fig.add_subplot(grid[1:, 0], sharey=main_ax)
+        y_hist.hist(y, bins=50, orientation="horizontal", align="mid", rwidth=0.8)
+        y_hist.invert_xaxis()
+        y_hist.tick_params(left=True, labelleft=True)
+        y_hist.set_ylabel(f"return (after {return_minutes} minutes)")
+
+        plt.tight_layout()
+        plt.savefig(f"feature_vs_return_{return_minutes}.png")
+        plt.close()
+
+    def diff_feature(self) -> pd.Series:
+        """
+        Calculate difference of funding rate
+        """
+        return self._feature.diff()
+
+    def square_feature(self) -> pd.Series:
+        """
+        Calculate square of funding rate
+        """
+        return self._feature**2
+
+    def cube_feature(self) -> pd.Series:
+        """
+        Calculate cube of funding rate
+        """
+        return self._feature**3
+
+    def exp_feature(self) -> pd.Series:
+        """
+        Calculate exp of funding rate
+        """
+        return np.exp(self._feature)
+
+    def sin_feature(self) -> pd.Series:
+        """
+        Calculate sin of funding rate
+        """
+        return np.sin(self._feature)
+
+    def cos_feature(self) -> pd.Series:
+        """
+        Calculate cos of funding rate
+        """
+        return np.cos(self._feature)
+
+    def tan_feature(self) -> pd.Series:
+        """
+        Calculate tan of funding rate
+        """
+        return np.tan(self._feature)
+
+    def tanh_feature(self) -> pd.Series:
+        """
+        Calculate tanh of funding rate
+        """
+        return np.tanh(self._feature)
+
+    def sigmoid_feature(self) -> pd.Series:
+        """
+        Calculate sigmoid of funding rate
+        """
+        return 1 / (1 + np.exp(-self._feature))
+
+    def softmax_feature(self) -> pd.Series:
+        """
+        Calculate softmax of funding rate
+        """
+        return np.exp(self._feature) / np.sum(np.exp(self._feature))
+
+    def log_feature(self) -> pd.Series:
+        """
+        Calculate log of funding rate
+        """
+        return np.log(self._feature)
+
+    def log10_feature(self) -> pd.Series:
+        """
+        Calculate log10 of funding rate
+        """
+        return np.log10(self._feature)
+
+    def log2_feature(self) -> pd.Series:
+        """
+        Calculate log2 of funding rate
+        """
+        return np.log2(self._feature)
+
+    def square_root_feature(self) -> pd.Series:
+        """
+        Calculate square root of funding rate
+        """
+        return np.sqrt(self._feature)
+
+    def arctan_feature(self) -> pd.Series:
+        """
+        Calculate arctan of funding rate
+        """
+        return np.arctan(self._feature)
+
+    def arcsin_feature(self) -> pd.Series:
+        """
+        Calculate arcsin of funding rate
+        """
+        return np.arcsin(self._feature)
+
+    def arccos_feature(self) -> pd.Series:
+        """
+        Calculate arccos of funding rate
+        """
+        return np.arccos(self._feature)
+
+    def arctanh_feature(self) -> pd.Series:
+        """
+        Calculate arctanh of funding rate
+        """
+        return np.arctanh(self._feature)
+
+    def arcsinh_feature(self) -> pd.Series:
+        """
+        Calculate arcsinh of funding rate
+        """
+        return np.arcsinh(self._feature)
+
+    def arccosh_feature(self) -> pd.Series:
+        """
+        Calculate arccosh of funding rate
+        """
+        return np.arccosh(self._feature)
+
+    def absolute_feature(self) -> pd.Series:
+        """
+        Calculate absolute of funding rate
+        """
+        return np.absolute(self._feature)
+
+    def reciprocal_feature(self) -> pd.Series:
+        """
+        Calculate reciprocal of funding rate
+        """
+        return np.reciprocal(self._feature)
+
+    def negative_feature(self) -> pd.Series:
+        """
+        Calculate negative of funding rate
+        """
+        return np.negative(self._feature)
+
+    def sign_feature(self) -> pd.Series:
+        """
+        Calculate sign of funding rate
+        """
+        return np.sign(self._feature)
+
+    def ceil_feature(self) -> pd.Series:
+        """
+        Calculate ceil of funding rate
+        """
+        return np.ceil(self._feature)
+
+    def floor_feature(self) -> pd.Series:
+        """
+        Calculate floor of funding rate
+        """
+        return np.floor(self._feature)
+
+    def rint_feature(self) -> pd.Series:
+        """
+        Calculate rint of funding rate
+        """
+        return np.rint(self._feature)
+
+    def trunc_feature(self) -> pd.Series:
+        """
+        Calculate trunc of funding rate
+        """
+        return np.trunc(self._feature)
diff --git a/crypto_features/feature/information_correlation.py b/crypto_features/feature/information_correlation.py
index 20bf437..b7fcb49 100644
--- a/crypto_features/feature/information_correlation.py
+++ b/crypto_features/feature/information_correlation.py
@@ -20,19 +20,14 @@ def __init__(self):
         pass
 
     @staticmethod
-    def run_calculate(
-        klines: pd.DataFrame, feature: pd.Series, return_minutes=1, **kwargs
-    ):
+    def format_array(klines: pd.DataFrame, feature: pd.Series, return_minutes=1):
         """
-        Calculate and visualize the information correlation.
-
+        Format the array.
         :param klines: The klines data.
         :param feature: The feature data.
         :param return_minutes: The return minutes.
+        :return: formatted feature and return array.
         """
-        if not os.path.exists("information_correlation"):
-            os.mkdir("information_correlation")
-
         close_chg_pct_header = f"close_chg_pct_after_{return_minutes}min"
         klines["close"] = klines["close"].astype(float)
         klines[close_chg_pct_header] = klines["close"].pct_change(
@@ -49,14 +44,33 @@ def run_calculate(
         klines[close_chg_pct_header] = klines[close_chg_pct_header].round(4)
 
         feature_arr = feature[feature.index.isin(klines.index)].values
-        klines_arr = klines[klines.index.isin(feature.index)][
+        return_arr = klines[klines.index.isin(feature.index)][
             close_chg_pct_header
         ].values
 
         assert len(feature_arr) == len(
-            klines_arr
-        ), f"len(feature_arr)={len(feature_arr)}, len(klines_arr)={len(klines_arr)}"
+            return_arr
+        ), f"len(feature_arr)={len(feature_arr)}, len(return_arr)={len(return_arr)}"
+
+        return feature_arr, return_arr
+
+    @staticmethod
+    def run_calculate(
+        klines: pd.DataFrame, feature: pd.Series, return_minutes=1, **kwargs
+    ):
+        """
+        Calculate and visualize the information correlation.
+
+        :param klines: The klines data.
+        :param feature: The feature data.
+        :param return_minutes: The return minutes.
+        """
+        if not os.path.exists("information_correlation"):
+            os.mkdir("information_correlation")
 
+        feature_arr, klines_arr = InformationCorrelation.format_array(
+            klines, feature, return_minutes
+        )
         print("[green] Start calculating the information correlation... [/green]")
 
         # Pearson's correlation coefficient
diff --git a/crypto_features/feature/preprocessing.py b/crypto_features/feature/preprocessing.py
index 86b5726..1825aaa 100644
--- a/crypto_features/feature/preprocessing.py
+++ b/crypto_features/feature/preprocessing.py
@@ -111,6 +111,7 @@ def _load_klines_data(self, symbol) -> pd.DataFrame:
 
         df.set_index("timestamp_open", inplace=True)
         df.index = pd.to_datetime(df.index, utc=True, unit="ms")
+        df["close"] = df["close"].astype(float)
 
         return df
 
@@ -186,6 +187,7 @@ def _load_klines_data(self, symbol) -> pd.DataFrame:
         df = df.drop(["index", "index2"], axis=1)
         df["timestamp_open"] = pd.to_datetime(df["timestamp_open"], utc=True)
         df.set_index("timestamp_open", inplace=True)
+        df["close"] = df["close"].astype(float)
 
         return df