diff --git a/reinforcement-learning/DemoGym.ipynb b/reinforcement-learning/DemoGym.ipynb
new file mode 100644
index 0000000..49f1bf4
--- /dev/null
+++ b/reinforcement-learning/DemoGym.ipynb
@@ -0,0 +1,86 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "71383e8d-63f1-462c-bd77-688d8d34a60a",
+   "metadata": {},
+   "source": [
+    "# Demonstration of `gym`: Visualize Interactive Results in Jupyter Notebook"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "eae51654-4ccf-44ed-aaac-f1d993d7e4a1",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import matplotlib.pyplot as plt\n",
+    "from pyvirtualdisplay import Display\n",
+    "display = Display(visible=0, size=(1400, 900))\n",
+    "display.start()\n",
+    "\n",
+    "is_ipython = 'inline' in plt.get_backend()\n",
+    "if is_ipython:\n",
+    "    from IPython import display\n",
+    "\n",
+    "plt.ion()\n",
+    "\n",
+    "# Load the gym environment"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "be872e01-e4fd-4940-874e-d46e97fb3519",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import gym\n",
+    "import random\n",
+    "%matplotlib inline\n",
+    "\n",
+    "env = gym.make('LunarLander-v2')\n",
+    "env.seed(23)\n",
+    "\n",
+    "# Let's watch how an untrained agent moves around\n",
+    "\n",
+    "state = env.reset()\n",
+    "img = plt.imshow(env.render(mode='rgb_array'))\n",
+    "for j in range(200):\n",
+    "#     action = agent.act(state)\n",
+    "    action = random.choice(range(4))\n",
+    "    img.set_data(env.render(mode='rgb_array')) \n",
+    "    plt.axis('off')\n",
+    "    display.display(plt.gcf())\n",
+    "    display.clear_output(wait=True)\n",
+    "    state, reward, done, _ = env.step(action)\n",
+    "    if done:\n",
+    "        break\n",
+    "\n",
+    "env.close()"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/reinforcement-learning/DemoMUD.ipynb b/reinforcement-learning/DemoMUD.ipynb
new file mode 100644
index 0000000..21a9ecc
--- /dev/null
+++ b/reinforcement-learning/DemoMUD.ipynb
@@ -0,0 +1,74 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "2e848ca9-c915-4aa2-a7cc-a5654ed06863",
+   "metadata": {},
+   "source": [
+    "# Demonstration of Training and Testing"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "a9506e99-a947-4f69-8355-a3ce696793fa",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from main import train, test\n",
+    "import pickle"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "de500d9e-40d1-4b6b-900f-96c2ec69e464",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "data = pickle.load(open(\"data.pkl\", \"rb\"))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "39ca7791-c844-4231-9f3b-e8ae80fe8103",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "mud_point = train(data)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "8d8c70ab-d055-418c-b67e-ba5109d989f3",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "test(mud_point)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}
diff --git a/reinforcement-learning/README.md b/reinforcement-learning/README.md
new file mode 100644
index 0000000..be3c602
--- /dev/null
+++ b/reinforcement-learning/README.md
@@ -0,0 +1,72 @@
+# PREFACE
+
+This is a direct migration (stripping `git` history) of [mud-games](https://git.mlden.com/mm/mud-games) (as of commit `1a2259827f`) which shows an actual research-oriented experiment which involves a novel method of "training" (this `mud` stuff) and "testing" (visually).
+The intent was to explore a utility library named [`gym`](https://github.com/openai/gym) which provides a consistent interface with which to train reinforcement-learning algorithms, and try to "learn to win" one of its most basic games (`Cartpole-V1`).
+
+
+Takeaways from this example:
+
+- much more friendly for reproducibility
+- runs on desktop AND in notebook (handling visual output is tricky, leverage the patterns here if you need to move interactive outputs into the cloud)
+- functions defined in `main.py` are "clean" but still not "clear"
+- notice the lack of documntation: where would it be helpful to have it?
+- data is not only supplied (perhaps not good to commit it) but a method to generate it is also provided (takes some time)
+- notice the comprehensive `README` below
+
+# mud-games
+
+control systems with MUD points
+
+
+# installation
+
+```bash
+pip install -r requirements.txt
+```
+
+
+# usage
+
+A `data.pkl` file is provided for your convenience with input / output samples.
+
+```bash
+python main.py
+```
+
+You can also instead use the included [jupyter notebook](./DemoMUD.ipynb).
+
+
+# info
+
+The inputs are the parameters to a `1x4` matrix which is multiplied against the observations of the state in order to make a decision for the next action (push left or right). The output of the vector inner-product is binarized by comparing it to zero as a threshold value.
+
+The parameter space is standard normal.
+There is no assumed error in observations; the "data variance" is designed to reflect the acceptable [ranges for the observations](https://www.gymlibrary.ml/pages/environments/classic_control/cart_pole):
+- The cart x-position (index 0) can be take values between (-4.8, 4.8), but the episode terminates if the cart leaves the (-2.4, 2.4) range.
+- The pole angle can be observed between (-.418, .418) radians (or ±24°), but the episode terminates if the pole angle is not in the range (-.2095, .2095) (or ±12°)
+
+
+Therefore, since our objective is to stabilize the cart, the target "time series signal" is zero for all four dimensions of the observation space. The presumed "data variance" should actually correspond to the acceptable bands of signal (WIP).
+
+
+# generate data
+
+You can generate your own data with:
+```bash
+python sample.py
+```
+
+Note: if you change the presumed sample space in `data.py`, you should make the corresponding changes to the initial distribution in `main.py`.
+
+
+# improvements
+
+Using the following presumptions, we can establish better values for the "data variance":
+
+> The angular momentum of the pole is the most important thing to stabilize.
+
+
+# headless mode / notebook demos
+
+Run `./headless.sh` (requires `sudo`) to install virtual displays so you can use the included Jupyter notebooks.
+
diff --git a/reinforcement-learning/data.pkl b/reinforcement-learning/data.pkl
new file mode 100644
index 0000000..2a3e955
Binary files /dev/null and b/reinforcement-learning/data.pkl differ
diff --git a/reinforcement-learning/headless.sh b/reinforcement-learning/headless.sh
new file mode 100755
index 0000000..41a757a
--- /dev/null
+++ b/reinforcement-learning/headless.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+sudo apt update && sudo apt install build-essential xvfb swig
+pip install box2d-py pyvirtualdisplay
diff --git a/reinforcement-learning/main.py b/reinforcement-learning/main.py
new file mode 100644
index 0000000..40dc553
--- /dev/null
+++ b/reinforcement-learning/main.py
@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+import pickle
+
+import gym
+import numpy as np
+import pandas as pd
+from scipy.stats import gaussian_kde as gkde
+from scipy.stats import norm
+
+import matplotlib.pyplot as plt
+
+try:
+    from pyvirtualdisplay import Display
+    display = Display(visible=0, size=(1400, 900))
+    display.start()
+except ImportError:
+    pass
+
+is_ipython = 'inline' in plt.get_backend()
+if is_ipython:
+    from IPython import display
+
+plt.ion()
+
+def train(data):
+    D = pd.DataFrame(data)
+    sd = np.array([1.0, 0.5, 0.2, 0.5])
+    D["qoi"] = D["obs"].apply(lambda o: np.sum(o, axis=0) / sd / np.sqrt(len(o)))
+    D["i"] = D["lam"].apply(lambda l: norm.pdf(l).prod())
+    D["o"] = D["qoi"].apply(lambda q: norm.pdf(q).prod())
+    Q = np.array(D["qoi"].to_list()).reshape(-1, 4)
+    K = [gkde(Q[:, i]) for i in range(4)]
+    D["p"] = D["qoi"].apply(lambda q: np.prod([K[i].pdf(q[i]) for i in range(4)]))
+    D["u"] = D["i"] * D["o"] / D["p"]
+    mud_point_idx = D["u"].argmax()
+    mud_point = D["lam"].iloc[mud_point_idx]
+    print(f"MUD Point {mud_point_idx}: {mud_point}")
+    return mud_point
+
+
+def test(decision=np.array([-0.09, -0.71, -0.43, -0.74]), seed=1992):
+    env = gym.make("CartPole-v1")
+    observation, info = env.reset(seed=seed, return_info=True)
+    score = 0
+    if is_ipython:
+        img = plt.imshow(env.render(mode='rgb_array'))
+    for i in range(10000):
+        action = 1 if decision.T @ observation < 0 else 0
+        observation, reward, done, info = env.step(action)
+        score += reward
+        if not is_ipython:
+            env.render()
+        else:
+            img.set_data(env.render(mode='rgb_array'))
+            plt.axis('off')
+            display.display(plt.gcf())
+            display.clear_output(wait=True)
+        if done:
+            if score == 500:
+                print("WIN")
+            else:
+                print(f"LOSE: {int(score)}")
+            score = 0  # reset score
+            observation, info = env.reset(return_info=True)
+    env.close()
+
+
+if __name__ == "__main__":
+    data = pickle.load(open("data.pkl", "rb"))
+    mud_point = train(data)
+    test(mud_point)
diff --git a/reinforcement-learning/requirements.txt b/reinforcement-learning/requirements.txt
new file mode 100644
index 0000000..eb75ae1
--- /dev/null
+++ b/reinforcement-learning/requirements.txt
@@ -0,0 +1,5 @@
+scipy
+numpy
+gym[classic_control]
+matplotlib
+pandas
diff --git a/reinforcement-learning/sample.py b/reinforcement-learning/sample.py
new file mode 100644
index 0000000..679f94a
--- /dev/null
+++ b/reinforcement-learning/sample.py
@@ -0,0 +1,65 @@
+import pickle
+import gym
+import numpy as np
+from matplotlib import pyplot as plt
+
+# numpy precision for printing
+np.set_printoptions(precision=3, suppress=True)
+
+plt.ion()  # interactive plotting
+fig, ax = plt.subplots()
+colors = ["xkcd:orange", "xkcd:forest green", "xkcd:gray", "xkcd:light blue"]
+plots = [None] * 4
+
+env = gym.make("CartPole-v1")
+observation, info = env.reset(seed=42, return_info=True)
+
+max_steps = 100
+num_samples = 500
+samples = np.random.randn(num_samples, 4)
+
+data = []
+for lam in samples:
+    breakpoints = []
+    score = 0
+    obs = []
+    for n in range(max_steps):
+        ax.cla()
+        # action = env.action_space.sample()
+        action = 1 if lam.T @ observation < 0 else 0
+        # action = 1 if observation[0] - observation[3]  < 0 else 0
+        observation, reward, done, info = env.step(action)
+        score += reward
+        obs.append(observation.tolist())
+        o = np.array(obs)
+        var = np.var(o[-int(score) :, :], axis=0)
+        for q in range(4):
+            lines = np.hstack([o[:, q], np.zeros(max_steps - n)])
+            ax.plot(range(max_steps + 1), lines, c=colors[q])
+
+        ax.set_title(f"Reward: {int(score)}, Variance: {var}")
+        ax.set_ylim([-3, 3])
+
+        if done or n == max_steps:
+            breakpoints.append(n)
+            observation, info = env.reset(return_info=True)
+            # print(score, observation)
+            score = 0  # reset score
+
+        # draw break-point lines when game is lost
+        for b in breakpoints:
+            ax.vlines(
+                b, np.min(o, axis=0).min(), np.max(o, axis=0).max(), color="black", lw=2
+            )
+
+        fig.canvas.draw()
+        fig.show()
+        fig.canvas.flush_events()
+        env.render()
+
+    data.append({"lam": lam, "obs": obs, "break": breakpoints})
+    pickle.dump(data, open("data.pkl", "wb"))  # dump data frequently
+
+stop = input("Press any key to close.")
+plt.close()
+env.close()