diff --git a/.github/workflows/basic_test.yml b/.github/workflows/basic_test.yml
index d6b5a4c..942454c 100644
--- a/.github/workflows/basic_test.yml
+++ b/.github/workflows/basic_test.yml
@@ -56,12 +56,16 @@ jobs:
           python -m pytest ./tests/test_basic_space.py -s
         shell: bash
 
-      - name: Test Synthetic Data
+      - name: Test Math
         run: |
           python -m pip install pytest numpy
           python -m pip install parameterized
           python -m pip install torch torchvision
           python --version
           python -m pytest ./tests/test_math*.py -s
+        shell: bash
+
+      - name: Test Synthetic Data
+        run: |
           python -m pytest ./tests/test_synthetic*.py -s
         shell: bash
diff --git a/exps/LFNA/lfna.py b/exps/LFNA/lfna.py
index f0ec021..71b9b0b 100644
--- a/exps/LFNA/lfna.py
+++ b/exps/LFNA/lfna.py
@@ -222,7 +222,7 @@ def pretrain_v2(base_model, meta_model, criterion, xenv, args, logger):
 
 
 def main(args):
-    logger, env_info, model_kwargs = lfna_setup(args)
+    logger, model_kwargs = lfna_setup(args)
     train_env = get_synthetic_env(mode="train", version=args.env_version)
     valid_env = get_synthetic_env(mode="valid", version=args.env_version)
     all_env = get_synthetic_env(mode=None, version=args.env_version)
diff --git a/exps/LFNA/lfna_utils.py b/exps/LFNA/lfna_utils.py
index 44489e1..ea9451d 100644
--- a/exps/LFNA/lfna_utils.py
+++ b/exps/LFNA/lfna_utils.py
@@ -11,33 +11,6 @@ from xautodl.datasets.synthetic_core import get_synthetic_env
 def lfna_setup(args):
     prepare_seed(args.rand_seed)
     logger = prepare_logger(args)
-
-    cache_path = (
-        logger.path(None) / ".." / "env-{:}-info.pth".format(args.env_version)
-    ).resolve()
-    if cache_path.exists():
-        env_info = torch.load(cache_path)
-    else:
-        env_info = dict()
-        dynamic_env = get_synthetic_env(version=args.env_version)
-        env_info["total"] = len(dynamic_env)
-        for idx, (timestamp, (_allx, _ally)) in enumerate(tqdm(dynamic_env)):
-            env_info["{:}-timestamp".format(idx)] = timestamp
-            env_info["{:}-x".format(idx)] = _allx
-            env_info["{:}-y".format(idx)] = _ally
-        env_info["dynamic_env"] = dynamic_env
-        torch.save(env_info, cache_path)
-
-    """
-    model_kwargs = dict(
-        config=dict(model_type="simple_mlp"),
-        input_dim=1,
-        output_dim=1,
-        hidden_dim=args.hidden_dim,
-        act_cls="leaky_relu",
-        norm_cls="identity",
-    )
-    """
     model_kwargs = dict(
         config=dict(model_type="norm_mlp"),
         input_dim=1,
@@ -46,7 +19,7 @@ def lfna_setup(args):
         act_cls="gelu",
         norm_cls="layer_norm_1d",
     )
-    return logger, env_info, model_kwargs
+    return logger, model_kwargs
 
 
 def train_model(model, dataset, lr, epochs):
diff --git a/exps/LFNA/vis-synthetic.py b/exps/LFNA/vis-synthetic.py
index 027776e..d30ac38 100644
--- a/exps/LFNA/vis-synthetic.py
+++ b/exps/LFNA/vis-synthetic.py
@@ -20,14 +20,13 @@ matplotlib.use("agg")
 import matplotlib.pyplot as plt
 import matplotlib.ticker as ticker
 
-lib_dir = (Path(__file__).parent / ".." / ".." / "lib").resolve()
+lib_dir = (Path(__file__).parent / ".." / "..").resolve()
 if str(lib_dir) not in sys.path:
     sys.path.insert(0, str(lib_dir))
 
-from models.xcore import get_model
-from datasets.synthetic_core import get_synthetic_env
-from utils.temp_sync import optimize_fn, evaluate_fn
-from procedures.metric_utils import MSEMetric
+from xautodl.models.xcore import get_model
+from xautodl.datasets.synthetic_core import get_synthetic_env
+from xautodl.procedures.metric_utils import MSEMetric
 
 
 def plot_scatter(cur_ax, xs, ys, color, alpha, linewidths, label=None):
@@ -181,10 +180,17 @@ def compare_cl(save_dir):
 
 def visualize_env(save_dir, version):
     save_dir = Path(str(save_dir))
-    save_dir.mkdir(parents=True, exist_ok=True)
+    for substr in ("pdf", "png"):
+        sub_save_dir = save_dir / substr
+        sub_save_dir.mkdir(parents=True, exist_ok=True)
 
     dynamic_env = get_synthetic_env(version=version)
-    min_t, max_t = dynamic_env.min_timestamp, dynamic_env.max_timestamp
+    # min_t, max_t = dynamic_env.min_timestamp, dynamic_env.max_timestamp
+    allxs, allys = [], []
+    for idx, (timestamp, (allx, ally)) in enumerate(tqdm(dynamic_env, ncols=50)):
+        allxs.append(allx)
+        allys.append(ally)
+    allxs, allys = torch.cat(allxs).view(-1), torch.cat(allys).view(-1)
     for idx, (timestamp, (allx, ally)) in enumerate(tqdm(dynamic_env, ncols=50)):
         dpi, width, height = 30, 1800, 1400
         figsize = width / float(dpi), height / float(dpi)
@@ -201,21 +207,18 @@ def visualize_env(save_dir, version):
             tick.label.set_rotation(10)
         for tick in cur_ax.yaxis.get_major_ticks():
             tick.label.set_fontsize(LabelSize - font_gap)
-        if version == "v1":
-            cur_ax.set_xlim(-2, 2)
-            cur_ax.set_ylim(-8, 8)
-        elif version == "v2":
-            cur_ax.set_xlim(-10, 10)
-            cur_ax.set_ylim(-60, 60)
+        cur_ax.set_xlim(round(allxs.min().item(), 1), round(allxs.max().item(), 1))
+        cur_ax.set_ylim(round(allys.min().item(), 1), round(allys.max().item(), 1))
         cur_ax.legend(loc=1, fontsize=LegendFontsize)
 
-        save_path = save_dir / "v{:}-{:05d}".format(version, idx)
-        fig.savefig(str(save_path) + ".pdf", dpi=dpi, bbox_inches="tight", format="pdf")
-        fig.savefig(str(save_path) + ".png", dpi=dpi, bbox_inches="tight", format="png")
+        pdf_save_path = save_dir / "pdf" / "v{:}-{:05d}.pdf".format(version, idx)
+        fig.savefig(str(pdf_save_path), dpi=dpi, bbox_inches="tight", format="pdf")
+        png_save_path = save_dir / "png" / "v{:}-{:05d}.png".format(version, idx)
+        fig.savefig(str(png_save_path), dpi=dpi, bbox_inches="tight", format="png")
         plt.close("all")
     save_dir = save_dir.resolve()
     base_cmd = "ffmpeg -y -i {xdir}/v{version}-%05d.png -vf scale=1800:1400 -pix_fmt yuv420p -vb 5000k".format(
-        xdir=save_dir, version=version
+        xdir=save_dir / "png", version=version
     )
     print(base_cmd)
     os.system("{:} {xdir}/env-{ver}.mp4".format(base_cmd, xdir=save_dir, ver=version))
@@ -371,7 +374,7 @@ if __name__ == "__main__":
     )
     args = parser.parse_args()
 
-    # visualize_env(os.path.join(args.save_dir, "vis-env"), "v1")
+    visualize_env(os.path.join(args.save_dir, "vis-env"), "v1")
     # visualize_env(os.path.join(args.save_dir, "vis-env"), "v2")
-    compare_algs(os.path.join(args.save_dir, "compare-alg"), args.env_version)
+    # compare_algs(os.path.join(args.save_dir, "compare-alg"), args.env_version)
     # compare_cl(os.path.join(args.save_dir, "compare-cl"))
diff --git a/exps/NAS-Bench-201/statistics-v2.py b/exps/NAS-Bench-201/statistics-v2.py
index 037af0f..d1a54a1 100644
--- a/exps/NAS-Bench-201/statistics-v2.py
+++ b/exps/NAS-Bench-201/statistics-v2.py
@@ -13,7 +13,10 @@ from xautodl.config_utils import dict2config
 
 # NAS-Bench-201 related module or function
 from xautodl.models import CellStructure, get_cell_based_tiny_net
-from xautodl.procedures import bench_pure_evaluate as pure_evaluate, get_nas_bench_loaders
+from xautodl.procedures import (
+    bench_pure_evaluate as pure_evaluate,
+    get_nas_bench_loaders,
+)
 from nas_201_api import NASBench201API, ArchResults, ResultsCount
 
 api = NASBench201API(
diff --git a/exps/experimental/test-dynamic.py b/exps/experimental/test-dynamic.py
new file mode 100644
index 0000000..a1a1e28
--- /dev/null
+++ b/exps/experimental/test-dynamic.py
@@ -0,0 +1,21 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019.08 #
+#####################################################
+# python test-dynamic.py
+#####################################################
+import sys
+from pathlib import Path
+
+lib_dir = (Path(__file__).parent / ".." / "..").resolve()
+print("LIB-DIR: {:}".format(lib_dir))
+if str(lib_dir) not in sys.path:
+    sys.path.insert(0, str(lib_dir))
+
+from xautodl.datasets.math_core import ConstantFunc
+from xautodl.datasets.math_core import GaussianDGenerator
+
+mean_generator = ConstantFunc(0)
+cov_generator = ConstantFunc(1)
+
+generator = GaussianDGenerator([mean_generator], [[cov_generator]], (-1, 1))
+generator(0, 10)
diff --git a/exps/experimental/test-ww-bench.py b/exps/experimental/test-ww-bench.py
index 21d7668..5f398b3 100644
--- a/exps/experimental/test-ww-bench.py
+++ b/exps/experimental/test-ww-bench.py
@@ -19,9 +19,11 @@ import seaborn as sns
 matplotlib.use("agg")
 import matplotlib.pyplot as plt
 
-lib_dir = (Path(__file__).parent / ".." / ".." / "lib").resolve()
+lib_dir = (Path(__file__).parent / ".." / "..").resolve()
+print("LIB-DIR: {:}".format(lib_dir))
 if str(lib_dir) not in sys.path:
     sys.path.insert(0, str(lib_dir))
+
 from log_utils import time_string
 from nats_bench import create
 from models import get_cell_based_tiny_net
diff --git a/exps/experimental/test-ww.py b/exps/experimental/test-ww.py
index 626a273..97597ca 100644
--- a/exps/experimental/test-ww.py
+++ b/exps/experimental/test-ww.py
@@ -3,11 +3,7 @@ from copy import deepcopy
 import torchvision.models as models
 from pathlib import Path
 
-lib_dir = (Path(__file__).parent / ".." / ".." / "lib").resolve()
-if str(lib_dir) not in sys.path:
-    sys.path.insert(0, str(lib_dir))
-
-from utils import weight_watcher
+from xautodl.utils import weight_watcher
 
 
 def main():
diff --git a/xautodl/datasets/math_adv_funcs.py b/xautodl/datasets/math_adv_funcs.py
index 2a093c7..e2529c0 100644
--- a/xautodl/datasets/math_adv_funcs.py
+++ b/xautodl/datasets/math_adv_funcs.py
@@ -17,10 +17,10 @@ from .math_base_funcs import QuarticFunc
 class ConstantFunc(FitFunc):
     """The constant function: f(x) = c."""
 
-    def __init__(self, constant=None):
+    def __init__(self, constant=None, xstr="x"):
         param = dict()
         param[0] = constant
-        super(ConstantFunc, self).__init__(0, None, param)
+        super(ConstantFunc, self).__init__(0, None, param, xstr)
 
     def __call__(self, x):
         self.check_valid()
@@ -37,6 +37,34 @@ class ConstantFunc(FitFunc):
 
 
 class ComposedSinFunc(FitFunc):
+    """The composed sin function that outputs:
+    f(x) = a * sin( b*x ) + c
+    """
+
+    def __init__(self, params, xstr="x"):
+        super(ComposedSinFunc, self).__init__(3, None, params, xstr)
+
+    def __call__(self, x):
+        self.check_valid()
+        a = self._params[0]
+        b = self._params[1]
+        c = self._params[2]
+        return a * math.sin(b * x) + c
+
+    def _getitem(self, x, weights):
+        raise NotImplementedError
+
+    def __repr__(self):
+        return "{name}({a} * sin({b} * {x}) + {c})".format(
+            name=self.__class__.__name__,
+            a=self._params[0],
+            b=self._params[1],
+            c=self._params[2],
+            x=self.xstr,
+        )
+
+
+class ComposedSinFuncV2(FitFunc):
     """The composed sin function that outputs:
       f(x) = amplitude-scale-of(x) * sin( period-phase-shift-of(x) )
     - the amplitude scale is a quadratic function of x
@@ -44,7 +72,7 @@ class ComposedSinFunc(FitFunc):
     """
 
     def __init__(self, **kwargs):
-        super(ComposedSinFunc, self).__init__(0, None)
+        super(ComposedSinFuncV2, self).__init__(0, None)
         self.fit(**kwargs)
 
     def __call__(self, x):
diff --git a/xautodl/datasets/math_base_funcs.py b/xautodl/datasets/math_base_funcs.py
index a77634b..e560755 100644
--- a/xautodl/datasets/math_base_funcs.py
+++ b/xautodl/datasets/math_base_funcs.py
@@ -5,15 +5,13 @@ import math
 import abc
 import copy
 import numpy as np
-from typing import Optional
 import torch
-import torch.utils.data as data
 
 
 class FitFunc(abc.ABC):
     """The fit function that outputs f(x) = a * x^2 + b * x + c."""
 
-    def __init__(self, freedom: int, list_of_points=None, params=None):
+    def __init__(self, freedom: int, list_of_points=None, params=None, xstr="x"):
         self._params = dict()
         for i in range(freedom):
             self._params[i] = None
@@ -24,6 +22,7 @@ class FitFunc(abc.ABC):
             self.fit(list_of_points=list_of_points)
         if params is not None:
             self.set(params)
+        self._xstr = str(xstr)
 
     def set(self, params):
         self._params = copy.deepcopy(params)
@@ -33,6 +32,13 @@ class FitFunc(abc.ABC):
             if value is None:
                 raise ValueError("The {:} is None".format(key))
 
+    @property
+    def xstr(self):
+        return self._xstr
+
+    def reset_xstr(self, xstr):
+        self._xstr = str(xstr)
+
     @abc.abstractmethod
     def __call__(self, x):
         raise NotImplementedError
@@ -106,8 +112,8 @@ class FitFunc(abc.ABC):
 class LinearFunc(FitFunc):
     """The linear function that outputs f(x) = a * x + b."""
 
-    def __init__(self, list_of_points=None, params=None):
-        super(LinearFunc, self).__init__(2, list_of_points, params)
+    def __init__(self, list_of_points=None, params=None, xstr="x"):
+        super(LinearFunc, self).__init__(2, list_of_points, params, xstr)
 
     def __call__(self, x):
         self.check_valid()
@@ -117,18 +123,19 @@ class LinearFunc(FitFunc):
         return weights[0] * x + weights[1]
 
     def __repr__(self):
-        return "{name}({a} * x + {b})".format(
+        return "{name}({a} * {x} + {b})".format(
             name=self.__class__.__name__,
             a=self._params[0],
             b=self._params[1],
+            x=self.xstr,
         )
 
 
 class QuadraticFunc(FitFunc):
     """The quadratic function that outputs f(x) = a * x^2 + b * x + c."""
 
-    def __init__(self, list_of_points=None, params=None):
-        super(QuadraticFunc, self).__init__(3, list_of_points, params)
+    def __init__(self, list_of_points=None, params=None, xstr="x"):
+        super(QuadraticFunc, self).__init__(3, list_of_points, params, xstr)
 
     def __call__(self, x):
         self.check_valid()
@@ -138,11 +145,12 @@ class QuadraticFunc(FitFunc):
         return weights[0] * x * x + weights[1] * x + weights[2]
 
     def __repr__(self):
-        return "{name}({a} * x^2 + {b} * x + {c})".format(
+        return "{name}({a} * {x}^2 + {b} * {x} + {c})".format(
             name=self.__class__.__name__,
             a=self._params[0],
             b=self._params[1],
             c=self._params[2],
+            x=self.xstr,
         )
 
 
@@ -165,12 +173,13 @@ class CubicFunc(FitFunc):
         return weights[0] * x ** 3 + weights[1] * x ** 2 + weights[2] * x + weights[3]
 
     def __repr__(self):
-        return "{name}({a} * x^3 + {b} * x^2 + {c} * x + {d})".format(
+        return "{name}({a} * {x}^3 + {b} * {x}^2 + {c} * {x} + {d})".format(
             name=self.__class__.__name__,
             a=self._params[0],
             b=self._params[1],
             c=self._params[2],
             d=self._params[3],
+            x=self.xstr,
         )
 
 
diff --git a/xautodl/datasets/math_core.py b/xautodl/datasets/math_core.py
index 5dd2429..2579282 100644
--- a/xautodl/datasets/math_core.py
+++ b/xautodl/datasets/math_core.py
@@ -6,3 +6,4 @@ from .math_dynamic_funcs import DynamicLinearFunc
 from .math_dynamic_funcs import DynamicQuadraticFunc
 from .math_adv_funcs import ConstantFunc
 from .math_adv_funcs import ComposedSinFunc
+from .math_dynamic_generator import GaussianDGenerator
diff --git a/xautodl/datasets/math_dynamic_funcs.py b/xautodl/datasets/math_dynamic_funcs.py
index e4e43c4..e83d8db 100644
--- a/xautodl/datasets/math_dynamic_funcs.py
+++ b/xautodl/datasets/math_dynamic_funcs.py
@@ -15,20 +15,19 @@ from .math_base_funcs import FitFunc
 class DynamicFunc(FitFunc):
     """The dynamic quadratic function, where each param is a function."""
 
-    def __init__(self, freedom: int, params=None):
-        super(DynamicFunc, self).__init__(freedom, None, params)
-        self._timestamp = None
+    def __init__(self, freedom: int, params=None, xstr="x"):
+        if params is not None:
+            for param in params:
+                param.reset_xstr("t") if isinstance(param, FitFunc) else None
+        super(DynamicFunc, self).__init__(freedom, None, params, xstr)
 
-    def __call__(self, x, timestamp=None):
+    def __call__(self, x, timestamp):
         raise NotImplementedError
 
     def _getitem(self, x, weights):
         raise NotImplementedError
 
-    def set_timestamp(self, timestamp):
-        self._timestamp = timestamp
-
-    def noise_call(self, x, timestamp=None, std=0.1):
+    def noise_call(self, x, timestamp, std):
         clean_y = self.__call__(x, timestamp)
         if isinstance(clean_y, np.ndarray):
             noise_y = clean_y + np.random.normal(scale=std, size=clean_y.shape)
@@ -42,13 +41,10 @@ class DynamicLinearFunc(DynamicFunc):
     The a and b is a function of timestamp.
     """
 
-    def __init__(self, params=None):
-        super(DynamicLinearFunc, self).__init__(3, params)
+    def __init__(self, params=None, xstr="x"):
+        super(DynamicLinearFunc, self).__init__(3, params, xstr)
 
-    def __call__(self, x, timestamp=None):
-        self.check_valid()
-        if timestamp is None:
-            timestamp = self._timestamp
+    def __call__(self, x, timestamp):
         a = self._params[0](timestamp)
         b = self._params[1](timestamp)
         convert_fn = lambda x: x[-1] if isinstance(x, (tuple, list)) else x
@@ -56,11 +52,11 @@ class DynamicLinearFunc(DynamicFunc):
         return a * x + b
 
     def __repr__(self):
-        return "{name}({a} * x + {b}, timestamp={timestamp})".format(
+        return "{name}({a} * {x} + {b})".format(
             name=self.__class__.__name__,
             a=self._params[0],
             b=self._params[1],
-            timestamp=self._timestamp,
+            x=self.xstr,
         )
 
 
diff --git a/xautodl/datasets/math_dynamic_generator.py b/xautodl/datasets/math_dynamic_generator.py
new file mode 100644
index 0000000..33fc478
--- /dev/null
+++ b/xautodl/datasets/math_dynamic_generator.py
@@ -0,0 +1,58 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.03 #
+#####################################################
+import abc
+import numpy as np
+
+
+def assert_list_tuple(x):
+    assert isinstance(x, (list, tuple))
+    return len(x)
+
+
+class DynamicGenerator(abc.ABC):
+    """The dynamic quadratic function, where each param is a function."""
+
+    def __init__(self):
+        self._ndim = None
+
+    def __call__(self, time, num):
+        raise NotImplementedError
+
+
+class GaussianDGenerator(DynamicGenerator):
+    def __init__(self, mean_functors, cov_functors, trunc=(-1, 1)):
+        super(GaussianDGenerator, self).__init__()
+        self._ndim = assert_list_tuple(mean_functors)
+        assert self._ndim == len(
+            cov_functors
+        ), "length does not match {:} vs. {:}".format(self._ndim, len(cov_functors))
+        assert_list_tuple(cov_functors)
+        for cov_functor in cov_functors:
+            assert self._ndim == assert_list_tuple(
+                cov_functor
+            ), "length does not match {:} vs. {:}".format(self._ndim, len(cov_functor))
+        assert (
+            isinstance(trunc, (list, tuple)) and len(trunc) == 2 and trunc[0] < trunc[1]
+        )
+        self._mean_functors = mean_functors
+        self._cov_functors = cov_functors
+        if trunc is not None:
+            assert assert_list_tuple(trunc) == 2 and trunc[0] < trunc[1]
+        self._trunc = trunc
+
+    def __call__(self, time, num):
+        mean_list = [functor(time) for functor in self._mean_functors]
+        cov_matrix = [
+            [abs(cov_gen(time)) for cov_gen in cov_functor]
+            for cov_functor in self._cov_functors
+        ]
+        values = np.random.multivariate_normal(mean_list, cov_matrix, size=num)
+        if self._trunc is not None:
+            np.clip(values, self._trunc[0], self._trunc[1], out=values)
+        return values
+
+    def __repr__(self):
+        return "{name}({ndim} dims, trunc={trunc})".format(
+            name=self.__class__.__name__, ndim=self._ndim, trunc=self._trunc
+        )
diff --git a/xautodl/datasets/synthetic_core.py b/xautodl/datasets/synthetic_core.py
index 5f2bfee..9a3eb2e 100644
--- a/xautodl/datasets/synthetic_core.py
+++ b/xautodl/datasets/synthetic_core.py
@@ -1,13 +1,14 @@
 #####################################################
 # Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.05 #
 #####################################################
+import math
 from .synthetic_utils import TimeStamp
-from .synthetic_env import EnvSampler
 from .synthetic_env import SyntheticDEnv
 from .math_core import LinearFunc
 from .math_core import DynamicLinearFunc
 from .math_core import DynamicQuadraticFunc
 from .math_core import ConstantFunc, ComposedSinFunc
+from .math_core import GaussianDGenerator
 
 
 __all__ = ["TimeStamp", "SyntheticDEnv", "get_synthetic_env"]
@@ -17,42 +18,21 @@ def get_synthetic_env(total_timestamp=1000, num_per_task=1000, mode=None, versio
     if version == "v1":
         mean_generator = ConstantFunc(0)
         std_generator = ConstantFunc(1)
-    elif version == "v2":
-        mean_generator = ComposedSinFunc()
-        std_generator = ComposedSinFunc(min_amplitude=0.5, max_amplitude=1.5)
-    else:
-        raise ValueError("Unknown version: {:}".format(version))
-    dynamic_env = SyntheticDEnv(
-        [mean_generator],
-        [[std_generator]],
-        num_per_task=num_per_task,
-        timestamp_config=dict(
-            min_timestamp=-0.5, max_timestamp=1.5, num=total_timestamp, mode=mode
-        ),
-    )
-    if version == "v1":
-        function = DynamicLinearFunc()
-        function_param = dict()
-        function_param[0] = ComposedSinFunc(
-            amplitude_scale=ConstantFunc(3.0),
-            num_sin_phase=9,
-            sin_speed_use_power=False,
+        data_generator = GaussianDGenerator(
+            [mean_generator], [[std_generator]], (-2, 2)
         )
-        function_param[1] = ConstantFunc(constant=0.9)
-    elif version == "v2":
-        function = DynamicQuadraticFunc()
-        function_param = dict()
-        function_param[0] = ComposedSinFunc(
-            num_sin_phase=4, phase_shift=1.0, max_amplitude=1.0
+        time_generator = TimeStamp(
+            min_timestamp=0, max_timestamp=math.pi * 6, num=total_timestamp, mode=mode
         )
-        function_param[1] = ConstantFunc(constant=0.9)
-        function_param[2] = ComposedSinFunc(
-            num_sin_phase=5, phase_shift=0.4, max_amplitude=0.9
+        oracle_map = DynamicLinearFunc(
+            params={
+                0: ComposedSinFunc(params={0: 2.0, 1: 1.0, 2: 2.2}),
+                1: ComposedSinFunc(params={0: 1.5, 1: 0.4, 2: 2.2}),
+            }
+        )
+        dynamic_env = SyntheticDEnv(
+            data_generator, oracle_map, time_generator, num_per_task
         )
     else:
         raise ValueError("Unknown version: {:}".format(version))
-
-    function.set(function_param)
-    # dynamic_env.set_oracle_map(copy.deepcopy(function))
-    dynamic_env.set_oracle_map(function)
     return dynamic_env
diff --git a/xautodl/datasets/synthetic_env.py b/xautodl/datasets/synthetic_env.py
index 8c7854c..66b5254 100644
--- a/xautodl/datasets/synthetic_env.py
+++ b/xautodl/datasets/synthetic_env.py
@@ -1,15 +1,9 @@
-#####################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.04 #
-#####################################################
 import math
 import random
-import numpy as np
 from typing import List, Optional, Dict
 import torch
 import torch.utils.data as data
 
-from .synthetic_utils import TimeStamp
-
 
 def is_list_tuple(x):
     return isinstance(x, (tuple, list))
@@ -38,46 +32,33 @@ class SyntheticDEnv(data.Dataset):
 
     def __init__(
         self,
-        mean_functors: List[data.Dataset],
-        cov_functors: List[List[data.Dataset]],
+        data_generator,
+        oracle_map,
+        time_generator,
         num_per_task: int = 5000,
-        timestamp_config: Optional[Dict] = None,
-        mode: Optional[str] = None,
-        timestamp_noise_scale: float = 0.3,
+        noise: float = 0.1,
     ):
-        self._ndim = len(mean_functors)
-        assert self._ndim == len(
-            cov_functors
-        ), "length does not match {:} vs. {:}".format(self._ndim, len(cov_functors))
-        for cov_functor in cov_functors:
-            assert self._ndim == len(
-                cov_functor
-            ), "length does not match {:} vs. {:}".format(self._ndim, len(cov_functor))
+        self._data_generator = data_generator
+        self._time_generator = time_generator
+        self._oracle_map = oracle_map
         self._num_per_task = num_per_task
-        if timestamp_config is None:
-            timestamp_config = dict(mode=mode)
-        elif "mode" not in timestamp_config:
-            timestamp_config["mode"] = mode
-
-        self._timestamp_generator = TimeStamp(**timestamp_config)
-        self._timestamp_noise_scale = timestamp_noise_scale
-
-        self._mean_functors = mean_functors
-        self._cov_functors = cov_functors
-
-        self._oracle_map = None
+        self._noise = noise
 
     @property
     def min_timestamp(self):
-        return self._timestamp_generator.min_timestamp
+        return self._time_generator.min_timestamp
 
     @property
     def max_timestamp(self):
-        return self._timestamp_generator.max_timestamp
+        return self._time_generator.max_timestamp
 
     @property
-    def timestamp_interval(self):
-        return self._timestamp_generator.interval
+    def time_interval(self):
+        return self._time_generator.interval
+
+    @property
+    def mode(self):
+        return self._time_generator.mode
 
     def random_timestamp(self, min_timestamp=None, max_timestamp=None):
         if min_timestamp is None:
@@ -89,16 +70,13 @@ class SyntheticDEnv(data.Dataset):
     def get_timestamp(self, index):
         if index is None:
             timestamps = []
-            for index in range(len(self._timestamp_generator)):
-                timestamps.append(self._timestamp_generator[index][1])
+            for index in range(len(self._time_generator)):
+                timestamps.append(self._time_generator[index][1])
             return tuple(timestamps)
         else:
-            index, timestamp = self._timestamp_generator[index]
+            index, timestamp = self._time_generator[index]
             return timestamp
 
-    def set_oracle_map(self, functor):
-        self._oracle_map = functor
-
     def __iter__(self):
         self._iter_num = 0
         return self
@@ -111,7 +89,7 @@ class SyntheticDEnv(data.Dataset):
 
     def __getitem__(self, index):
         assert 0 <= index < len(self), "{:} is not in [0, {:})".format(index, len(self))
-        index, timestamp = self._timestamp_generator[index]
+        index, timestamp = self._time_generator[index]
         return self.__call__(timestamp)
 
     def seq_call(self, timestamps):
@@ -122,52 +100,24 @@ class SyntheticDEnv(data.Dataset):
             return zip_sequence(xdata)
 
     def __call__(self, timestamp):
-        mean_list = [functor(timestamp) for functor in self._mean_functors]
-        cov_matrix = [
-            [abs(cov_gen(timestamp)) for cov_gen in cov_functor]
-            for cov_functor in self._cov_functors
-        ]
-
-        dataset = np.random.multivariate_normal(
-            mean_list, cov_matrix, size=self._num_per_task
+        dataset = self._data_generator(timestamp, self._num_per_task)
+        targets = self._oracle_map.noise_call(dataset, timestamp, self._noise)
+        return torch.Tensor([timestamp]), (
+            torch.Tensor(dataset),
+            torch.Tensor(targets),
         )
-        if self._oracle_map is None:
-            return torch.Tensor([timestamp]), torch.Tensor(dataset)
-        else:
-            targets = self._oracle_map.noise_call(dataset, timestamp)
-            return torch.Tensor([timestamp]), (
-                torch.Tensor(dataset),
-                torch.Tensor(targets),
-            )
 
     def __len__(self):
-        return len(self._timestamp_generator)
+        return len(self._time_generator)
 
     def __repr__(self):
         return "{name}({cur_num:}/{total} elements, ndim={ndim}, num_per_task={num_per_task}, range=[{xrange_min:.5f}~{xrange_max:.5f}], mode={mode})".format(
             name=self.__class__.__name__,
             cur_num=len(self),
-            total=len(self._timestamp_generator),
+            total=len(self._time_generator),
             ndim=self._ndim,
             num_per_task=self._num_per_task,
             xrange_min=self.min_timestamp,
             xrange_max=self.max_timestamp,
-            mode=self._timestamp_generator.mode,
+            mode=self.mode,
         )
-
-
-class EnvSampler:
-    def __init__(self, env, batch, enlarge):
-        indexes = list(range(len(env)))
-        self._indexes = indexes * enlarge
-        self._batch = batch
-        self._iterations = len(self._indexes) // self._batch
-
-    def __iter__(self):
-        random.shuffle(self._indexes)
-        for it in range(self._iterations):
-            indexes = self._indexes[it * self._batch : (it + 1) * self._batch]
-            yield indexes
-
-    def __len__(self):
-        return self._iterations
diff --git a/xautodl/datasets/synthetic_example.py b/xautodl/datasets/synthetic_example.py
deleted file mode 100644
index f5fea7b..0000000
--- a/xautodl/datasets/synthetic_example.py
+++ /dev/null
@@ -1,72 +0,0 @@
-#####################################################
-# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2021.04 #
-#####################################################
-import copy
-
-from .math_dynamic_funcs import DynamicLinearFunc, DynamicQuadraticFunc
-from .math_adv_funcs import ConstantFunc, ComposedSinFunc
-from .synthetic_env import SyntheticDEnv
-
-
-def create_example(timestamp_config=None, num_per_task=5000, indicator="v1"):
-    if indicator == "v1":
-        return create_example_v1(timestamp_config, num_per_task)
-    elif indicator == "v2":
-        return create_example_v2(timestamp_config, num_per_task)
-    else:
-        raise ValueError("Unkonwn indicator: {:}".format(indicator))
-
-
-def create_example_v1(
-    timestamp_config=None,
-    num_per_task=5000,
-):
-    mean_generator = ComposedSinFunc()
-    std_generator = ComposedSinFunc(min_amplitude=0.5, max_amplitude=0.5)
-
-    dynamic_env = SyntheticDEnv(
-        [mean_generator],
-        [[std_generator]],
-        num_per_task=num_per_task,
-        timestamp_config=timestamp_config,
-    )
-
-    function = DynamicQuadraticFunc()
-    function_param = dict()
-    function_param[0] = ComposedSinFunc(
-        num_sin_phase=4, phase_shift=1.0, max_amplitude=1.0
-    )
-    function_param[1] = ConstantFunc(constant=0.9)
-    function_param[2] = ComposedSinFunc(
-        num_sin_phase=5, phase_shift=0.4, max_amplitude=0.9
-    )
-    function.set(function_param)
-
-    dynamic_env.set_oracle_map(copy.deepcopy(function))
-    return dynamic_env, function
-
-
-def create_example_v2(
-    timestamp_config=None,
-    num_per_task=5000,
-):
-    mean_generator = ConstantFunc(0)
-    std_generator = ConstantFunc(1)
-
-    dynamic_env = SyntheticDEnv(
-        [mean_generator],
-        [[std_generator]],
-        num_per_task=num_per_task,
-        timestamp_config=timestamp_config,
-    )
-
-    function = DynamicLinearFunc()
-    function_param = dict()
-    function_param[0] = ComposedSinFunc(
-        amplitude_scale=ConstantFunc(1.0), period_phase_shift=ConstantFunc(1.0)
-    )
-    function_param[1] = ConstantFunc(constant=0.9)
-    function.set(function_param)
-
-    dynamic_env.set_oracle_map(copy.deepcopy(function))
-    return dynamic_env, function
diff --git a/xautodl/datasets/synthetic_utils.py b/xautodl/datasets/synthetic_utils.py
index 14d32a0..9c70e6b 100644
--- a/xautodl/datasets/synthetic_utils.py
+++ b/xautodl/datasets/synthetic_utils.py
@@ -13,11 +13,11 @@ class UnifiedSplit:
     """A class to unify the split strategy."""
 
     def __init__(self, total_num, mode):
-        # Training Set 60%
-        num_of_train = int(total_num * 0.6)
-        # Validation Set 20%
-        num_of_valid = int(total_num * 0.2)
-        # Test Set 20%
+        # Training Set 65%
+        num_of_train = int(total_num * 0.65)
+        # Validation Set 05%
+        num_of_valid = int(total_num * 0.05)
+        # Test Set 30%
         num_of_set = total_num - num_of_train - num_of_valid
         all_indexes = list(range(total_num))
         if mode is None:
@@ -28,6 +28,8 @@ class UnifiedSplit:
             self._indexes = all_indexes[num_of_train : num_of_train + num_of_valid]
         elif mode.lower() in ("test", "testing"):
             self._indexes = all_indexes[num_of_train + num_of_valid :]
+        elif mode.lower() in ("trainval", "trainvalidation"):
+            self._indexes = all_indexes[: num_of_train + num_of_valid]
         else:
             raise ValueError("Unkonwn mode of {:}".format(mode))
         self._all_indexes = all_indexes