plotlive

Interactive matplotlib-compatible graphs rendered with pygame. Write the same code you'd write for matplotlib — get a live, interactive window instead of a static plot.

Built for ML tutorial creators who want to explain concepts step by step with pan, zoom, hover tooltips, and frame-by-frame animation.

Install

python3 -m venv .venv
source .venv/bin/activate
pip3 install -e .

Quick start

import plotlive.pyplot as plt
import numpy as np

x = np.arange(50)
plt.plot(x, np.exp(-x/10), label='train loss')
plt.plot(x, np.exp(-x/12) + 0.05*np.random.randn(50), label='val loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.title('Training Curve')
plt.legend()
plt.grid()
plt.show()

---

Controls

Mouse

Action	Result
Scroll up	Zoom in (centered on cursor)
Scroll down	Zoom out (centered on cursor)
Click and drag	Pan the view
Double-click	Reset zoom and pan

Keyboard

Key	Action
? or H	Show / hide the help panel
Space	Play / pause animation
→ Right arrow	Step forward one frame (while paused)
← Left arrow	Step back one frame (while paused)
R	Reset zoom / pan + restart animation from frame 0 (paused)
S	Save current frame as frame_NNNN.png
Esc	Close the help panel

Animations start paused. Press Space to begin. Use ← / → to step one frame at a time.

Each subplot is independently interactive — zoom and pan apply only to the subplot your cursor is over.

---

Supported plot types

Function	EDA use case
plt.plot(x, y)	Line plots — training curves, time series
plt.scatter(x, y, c=labels)	Scatter — clusters, feature relationships
plt.hist(data, bins=20)	Histogram — feature distributions
plt.bar(x, height) / plt.barh(y, width)	Bar charts — feature importance, class counts
plt.imshow(matrix, cmap='Blues')	Heatmap — confusion matrix, correlation
plt.boxplot(data)	Box plot — distribution summary + outliers
plt.violinplot(data)	Violin plot — full distribution shape per group
plt.fill_between(x, y1, y2)	Shaded area — confidence bands, regions
plt.errorbar(x, y, yerr=std)	Error bars — mean ± std / confidence
plt.stackplot(x, y1, y2, y3)	Stacked area — cumulative contributions
plt.pie(values, labels=...)	Pie chart — class proportions

---

API reference

# ── Figure / layout ──────────────────────────────────────────────────
fig = plt.figure(figsize=(10, 6))
fig, ax = plt.subplots()
fig, axs = plt.subplots(2, 3, figsize=(14, 8))   # returns 2-D array of Axes
fig.suptitle('Overall title')
plt.tight_layout()
plt.savefig('output.png')
plt.save_animation('output.gif')   # requires: pip install Pillow
plt.save_animation('output.mp4')   # requires: pip install imageio[ffmpeg]
plt.show()

# ── Plots ────────────────────────────────────────────────────────────
plt.plot(x, y, 'b--', label='data', linewidth=2)
plt.scatter(x, y, c=colors, cmap='viridis', s=50, alpha=0.7)
plt.hist(data, bins=30, color='steelblue', edgecolor='white')
plt.bar(categories, values, color='steelblue')
plt.barh(categories, values)
plt.imshow(matrix, cmap='coolwarm', vmin=-1, vmax=1)
plt.colorbar()

plt.boxplot([group_a, group_b, group_c])
plt.violinplot([group_a, group_b], positions=[1, 2], widths=0.6)
plt.fill_between(x, y_low, y_high, alpha=0.3, color='steelblue')
plt.errorbar(x, y, yerr=std, fmt='o', capsize=4)
plt.stackplot(x, y1, y2, y3, labels=['A', 'B', 'C'], alpha=0.8)
plt.pie(values, labels=['Cat A', 'Cat B', 'Cat C'], startangle=90)

# ── Axes decoration ──────────────────────────────────────────────────
plt.xlabel('x label')
plt.ylabel('y label')
plt.title('Axes title')
plt.legend()
plt.grid()
plt.xlim(0, 10)
plt.ylim(-1, 1)
plt.xscale('log')
plt.yscale('log')
plt.xticks([0, 1, 2], ['zero', 'one', 'two'])
plt.yticks([0, 0.5, 1])
plt.axhline(y=0, color='k', linewidth=0.8)
plt.axvline(x=0, color='k', linewidth=0.8)

# ── OOP API ─────────────────────────────────────────────────────────
fig, ax = plt.subplots(2, 2, figsize=(12, 8))
ax[0, 0].plot(x, y)
ax[0, 1].scatter(x, y, c=labels, cmap='tab10')
ax[1, 0].boxplot([a, b, c])
ax[1, 1].violinplot(data)
ax[0, 0].set_xlabel('x'); ax[0, 0].set_ylabel('y')
ax[0, 0].set_title('subplot title')
ax[0, 0].legend(); ax[0, 0].grid()

# ── Animation ────────────────────────────────────────────────────────
def update(frame):
    plt.cla()
    plt.plot(x[:frame], y[:frame])
    plt.title(f'Frame {frame}')

plt.animate(update, frames=100, interval=50, repeat=True)
plt.show()

# ── Animation export ─────────────────────────────────────────────────
anim = plt.animate(update, frames=100, interval=50)
plt.save_animation('output.gif')        # requires: pip install Pillow
plt.save_animation('output.mp4')        # requires: pip install imageio[ffmpeg]
plt.save_animation('output.gif', fps=24)  # override frame rate
anim.save('output.gif')                 # or call directly on the object
plt.show()                              # interactive window opens afterwards

---

Animation

FuncAnimation — matplotlib-compatible

The animation class matches matplotlib.animation.FuncAnimation exactly, so existing matplotlib animation code runs unchanged:

from plotlive.animation import FuncAnimation

fig = plt.figure()
ax = fig.add_subplot(1, 1, 1)
x = np.linspace(-3, 3, 200)

def update(frame):
    ax.cla()
    ax.plot(x, np.sin(x + frame * 0.1))
    ax.set_title(f'Frame {frame}')

anim = FuncAnimation(fig, update, frames=60, interval=50, repeat=True)
plt.show()

All constructor parameters are supported:

Parameter	Default	Description
fig	—	Figure to animate
func	—	Called as func(frame, *fargs) each step
frames	None	int, list, generator, or None (→ 100 frames)
init_func	None	Accepted, not used (no blit)
fargs	None	Extra positional args forwarded to func
save_count	None	Frame count when frames is None
interval	200	Milliseconds between frames
repeat	True	Loop when finished
blit	False	Accepted, not used (full redraw always)

frames as a list passes the list values directly to func — matching matplotlib's behaviour:

# func receives 0.0, 0.5, 1.0, 1.5, … not the list index
anim = FuncAnimation(fig, update, frames=np.linspace(0, 2*np.pi, 60))

plt.animate() — convenience shorthand

plt.animate(update, frames=60, interval=50, repeat=True)
plt.show()

---

Animation export

Export any animation to a GIF or video file without opening a window.

Install

pip install plotlive[gif]           # GIF support  (Pillow)
pip install plotlive[video]         # MP4/MOV/AVI  (imageio + ffmpeg)
pip install plotlive[export]        # both

Or install the optional dependency directly:

pip install Pillow                      # for GIF
pip install imageio[ffmpeg]             # for MP4 / MOV / AVI

Usage

import plotlive.pyplot as plt
import numpy as np

x = np.linspace(-3, 3, 200)
w = [2.5]

def update(frame):
    w[0] -= 0.15 * 2 * w[0]
    plt.cla()
    plt.plot(x, x**2, 'b-', linewidth=2, label='f(w) = w²')
    plt.scatter([w[0]], [w[0]**2], c='red', s=120, label=f'w = {w[0]:.3f}')
    plt.ylim(-0.2, 7)
    plt.legend()
    plt.title(f'Gradient Descent — step {frame + 1}')

plt.animate(update, frames=25, interval=200)
plt.save_animation('gradient_descent.gif')  # export first
plt.show()                                   # then open interactive window

save_animation renders all frames off-screen — no window appears during export. After saving it restores the figure to frame 0 so the subsequent show() opens at the beginning.

Supported formats: .gif · .mp4 · .mov · .avi · .webm

API

Call	Description
plt.save_animation(filename)	Export current figure's animation
plt.save_animation(filename, fps=24)	Override frame rate
anim.save(filename)	Call on any FuncAnimation object
anim.save(filename, writer='pillow', fps=12)	Explicit writer (matplotlib-compatible)
anim.save(filename, writer='ffmpeg', fps=30)	ffmpeg writer
anim.save(filename, progress_callback=fn)	fn(current, total) called each frame

Default fps is derived from interval: fps = 1000 / interval. Accepted writer values: 'pillow' (GIF), 'ffmpeg' / 'imageio' (video), or None (inferred from extension).

Quick test

Run this one-liner — no window opens, it just renders and saves:

python3 -c "
import sys; sys.path.insert(0, 'src')
import plotlive.pyplot as plt, numpy as np
x = np.linspace(-3, 3, 200); w = [2.5]
def update(frame):
    w[0] -= 0.15 * 2 * w[0]; plt.cla()
    plt.plot(x, x**2, 'b-', linewidth=2, label='f(w)=w²')
    plt.scatter([w[0]], [w[0]**2], c='red', s=120, label=f'w={w[0]:.3f}')
    plt.ylim(-0.2, 7); plt.legend(); plt.title(f'Gradient Descent — step {frame+1}')
plt.animate(update, frames=20, interval=200)
plt.save_animation('gradient_descent.gif')
"

You should see frame progress printed to the terminal and a gradient_descent.gif appear in the current directory. Open it in any browser or image viewer to confirm it animates.

---

Examples

Run from the examples/ directory after activating the venv:

cd examples
source ../.venv/bin/activate

---

Static plots

Training curves

python3 -c "
import plotlive.pyplot as plt, numpy as np
x = np.arange(50)
plt.plot(x, np.exp(-x/10), label='train loss')
plt.plot(x, np.exp(-x/12) + 0.05*np.random.randn(50), label='val loss')
plt.fill_between(x, np.exp(-x/10)-0.05, np.exp(-x/10)+0.05, alpha=0.2, label='± 1σ')
plt.xlabel('Epoch'); plt.ylabel('Loss'); plt.title('Training Curve')
plt.legend(); plt.grid(); plt.show()
"

Confusion matrix

python3 -c "
import plotlive.pyplot as plt, numpy as np
cm = np.array([[50,2,1],[3,45,5],[2,4,48]])
fig, ax = plt.subplots()
im = ax.imshow(cm, cmap='Blues')
plt.colorbar(im, ax=ax); ax.set_title('Confusion Matrix'); plt.show()
"

Feature importance + error bars

python3 -c "
import plotlive.pyplot as plt, numpy as np
feats = ['age','income','tenure','score','region']
vals  = [0.40, 0.30, 0.18, 0.08, 0.04]
errs  = [0.04, 0.03, 0.02, 0.01, 0.005]
plt.barh(feats, vals)
plt.errorbar(vals, range(len(feats)), xerr=errs, fmt='none', color='black', capsize=4)
plt.xlabel('Importance'); plt.title('Feature Importance ± std'); plt.show()
"

Distribution comparison — box + violin

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(0)
data = [np.random.normal(m, s, 120) for m, s in [(0,1),(1,1.5),(3,0.5),(-1,2)]]
fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(11, 5))
ax1.boxplot(data); ax1.set_title('Box Plot')
ax2.violinplot(data); ax2.set_title('Violin Plot')
plt.show()
"

Correlation heatmap

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(0)
corr = np.corrcoef(np.random.randn(5, 100))
fig, ax = plt.subplots(figsize=(6,5))
im = ax.imshow(corr, cmap='coolwarm', vmin=-1, vmax=1)
plt.colorbar(im, ax=ax); ax.set_title('Correlation Matrix'); plt.show()
"

Stacked area — class proportions over time

python3 -c "
import plotlive.pyplot as plt, numpy as np
x = np.arange(20)
a = np.random.dirichlet([3,2,1], 20).T
plt.stackplot(x, a[0], a[1], a[2], labels=['Class A','Class B','Class C'], alpha=0.85)
plt.xlabel('Time step'); plt.ylabel('Proportion'); plt.title('Class Distribution Over Time')
plt.legend(); plt.show()
"

Pie chart — class balance

python3 -c "
import plotlive.pyplot as plt
plt.pie([52, 31, 17], labels=['Negative','Neutral','Positive'], startangle=90)
plt.title('Sentiment Distribution'); plt.legend(); plt.show()
"

---

Animated examples

Animations start paused. Press Space to play, ← / → to step frame by frame, S to save.

Gradient descent

python3 -c "
import plotlive.pyplot as plt, numpy as np
x = np.linspace(-3, 3, 200); w = [2.5]
def update(frame):
    plt.cla(); w[0] -= 0.15 * 2 * w[0]
    plt.plot(x, x**2, 'b-', linewidth=2, label='f(w)=w²')
    plt.scatter([w[0]], [w[0]**2], c='red', s=120, zorder=5, label=f'w={w[0]:.3f}')
    plt.fill_between(x, 0, x**2, alpha=0.07)
    plt.ylim(-0.2, 7); plt.legend(); plt.title(f'Gradient Descent — step {frame+1}')
plt.animate(update, frames=25, interval=200); plt.show()
"

K-means clustering

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(7); K=3
data = np.vstack([np.random.randn(60,2)*0.7+c for c in [(-2,-2),(2,-2),(0,2)]])
centroids = data[np.random.choice(len(data),K,replace=False)].copy()
def update(frame):
    global centroids
    labels = np.array([[np.linalg.norm(p-c) for c in centroids] for p in data]).argmin(1).astype(float)
    centroids = np.array([data[labels==k].mean(0) if (labels==k).any() else centroids[k] for k in range(K)])
    plt.cla(); plt.scatter(data[:,0],data[:,1],c=labels,cmap='viridis',s=30,alpha=0.7)
    plt.scatter(centroids[:,0],centroids[:,1],c='red',s=200,marker='*',zorder=5,label='Centroids')
    plt.legend(); plt.title(f'K-Means — iteration {frame+1}')
plt.animate(update, frames=12, interval=500); plt.show()
"

Multi-class classification boundaries

Trains a softmax classifier with gradient descent and draws the three learned decision boundary lines (one per pair of classes). Each class uses a distinct marker shape. Watch the lines rotate into place as accuracy climbs.

python3 -c "
import plotlive.pyplot as plt, numpy as np

np.random.seed(0)
K = 3
centers = [(-2, -1), (2, -1), (0, 2.5)]
X = np.vstack([np.random.randn(50, 2) * 0.8 + c for c in centers])
y = np.repeat(np.arange(K), 50)

W = np.zeros((2, K))
b = np.zeros(K)

MARKERS   = ['+',       'o',       '^'      ]
COLORS    = ['#e74c3c', '#3498db', '#2ecc71']
BD_COLORS = ['#8e44ad', '#e67e22', '#2c3e50']
x_edge = np.array([-5.5, 5.5])

def softmax(z):
    e = np.exp(z - z.max(axis=1, keepdims=True))
    return e / e.sum(axis=1, keepdims=True)

def plot_boundary(i, j, color):
    dw = W[:, i] - W[:, j]
    db = b[i] - b[j]
    if abs(dw[1]) < 1e-9:
        return
    plt.plot(x_edge, -(dw[0] * x_edge + db) / dw[1],
             color=color, linewidth=2, label=f'Boundary {i} vs {j}')

def update(frame):
    global W, b
    for _ in range(5):
        p = softmax(X @ W + b)
        oh = np.eye(K)[y]
        W -= 0.1 * (X.T @ (p - oh)) / len(X)
        b -= 0.1 * (p - oh).mean(axis=0)
    plt.cla()
    for k in range(K):
        m = y == k
        plt.scatter(X[m, 0], X[m, 1], c=COLORS[k], marker=MARKERS[k],
                    s=80, label=f'Class {k}')
    for (i, j), col in zip([(0, 1), (0, 2), (1, 2)], BD_COLORS):
        plot_boundary(i, j, col)
    acc = (np.argmax(X @ W + b, axis=1) == y).mean()
    plt.xlim(-5, 5); plt.ylim(-4, 5); plt.legend()
    plt.title(f'Softmax classifier — epoch {frame * 5} | acc {acc:.0%}')

plt.animate(update, frames=80, interval=100)
plt.show()
"

Export to GIF:

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(0); K=3
X=np.vstack([np.random.randn(50,2)*0.8+c for c in [(-2,-1),(2,-1),(0,2.5)]])
y=np.repeat(np.arange(K),50); W=np.zeros((2,K)); b=np.zeros(K)
MARKERS=['+','o','^']; COLORS=['#e74c3c','#3498db','#2ecc71']
BD_COLORS=['#8e44ad','#e67e22','#2c3e50']; x_edge=np.array([-5.5,5.5])
def softmax(z):
    e=np.exp(z-z.max(axis=1,keepdims=True)); return e/e.sum(axis=1,keepdims=True)
def plot_boundary(i,j,color):
    dw=W[:,i]-W[:,j]; db=b[i]-b[j]
    if abs(dw[1])<1e-9: return
    plt.plot(x_edge,-(dw[0]*x_edge+db)/dw[1],color=color,linewidth=2,label=f'Boundary {i} vs {j}')
def update(frame):
    global W,b
    for _ in range(5):
        p=softmax(X@W+b); oh=np.eye(K)[y]
        W-=0.1*(X.T@(p-oh))/len(X); b-=0.1*(p-oh).mean(axis=0)
    plt.cla()
    for k in range(K):
        m=y==k; plt.scatter(X[m,0],X[m,1],c=COLORS[k],marker=MARKERS[k],s=80,label=f'Class {k}')
    for (i,j),col in zip([(0,1),(0,2),(1,2)],BD_COLORS): plot_boundary(i,j,col)
    acc=(np.argmax(X@W+b,axis=1)==y).mean()
    plt.xlim(-5,5); plt.ylim(-4,5); plt.legend()
    plt.title(f'Softmax classifier — epoch {frame*5} | acc {acc:.0%}')
plt.animate(update, frames=60, interval=100)
plt.save_animation('classification.gif')
"

Neural network — hidden unit boundaries (ReLU)

Trains a 1-hidden-layer ReLU network on the two-moon dataset. Each subplot shows one hidden unit: the shaded region is where that unit fires (ReLU active), and the black line is its learned linear boundary. The output weight w= in the title shows how much each unit contributes to the final prediction.

Watch how eight straight lines, each specialising on a different slice of the space, combine to form the curved decision boundary needed to separate the two moons. Double-click any subplot to expand it with focus mode.

python3 -c "
import plotlive.pyplot as plt, numpy as np

np.random.seed(0)
n_h = 8

# Two-moon dataset
theta = np.linspace(0, np.pi, 60)
X0 = np.c_[np.cos(theta),   np.sin(theta)     ] + np.random.randn(60,2)*0.15
X1 = np.c_[1-np.cos(theta), 0.5-np.sin(theta) ] + np.random.randn(60,2)*0.15
X  = np.vstack([X0, X1]); X = (X - X.mean(0)) / X.std(0)
y  = np.repeat([0, 1], 60)

# Network weights
W1 = np.random.randn(2, n_h) * np.sqrt(2/2)
b1 = np.zeros(n_h)
W2 = np.random.randn(n_h, 1) * np.sqrt(2/n_h)
b2 = np.zeros(1)

# Decision-boundary mesh
g = 28
gx, gy  = np.linspace(-3, 3, g), np.linspace(-3, 3, g)
xx, yy  = np.meshgrid(gx, gy)
grid    = np.c_[xx.ravel(), yy.ravel()]
gx_flat = xx.ravel(); gy_flat = yy.ravel()
x_edge  = np.array([-3.5, 3.5])
COLORS  = ['#e74c3c', '#3498db']; MARKERS = ['o', '^']

def relu(z):    return np.maximum(0, z)
def sigmoid(z): return 1 / (1 + np.exp(-np.clip(z, -50, 50)))

def forward(Xb):
    z1 = Xb @ W1 + b1
    return sigmoid(relu(z1) @ W2 + b2).ravel(), z1

fig, axs = plt.subplots(2, 4, figsize=(14, 7))

def update(frame):
    global W1, b1, W2, b2
    lr = 0.05
    for _ in range(10):
        p, z1 = forward(X); a1 = relu(z1); N = len(X)
        dz2 = (p - y).reshape(-1, 1) / N
        dW2 = a1.T @ dz2;  db2 = dz2.sum(0)
        dz1 = (dz2 @ W2.T) * (z1 > 0)
        W1 -= lr * X.T @ dz1;  b1 -= lr * dz1.sum(0)
        W2 -= lr * dW2;         b2 -= lr * db2
    p_tr, _ = forward(X)
    acc = ((p_tr > 0.5).astype(int) == y).mean()
    _, z1_g = forward(grid)
    for i, ax in enumerate(axs.flat):
        ax.cla()
        active = z1_g[:, i] > 0
        ax.scatter(gx_flat[~active], gy_flat[~active], c='#eeeeee', s=55)
        ax.scatter(gx_flat[ active], gy_flat[ active], c='#c6e2f5', s=55)
        w, b = W1[:, i], b1[i]
        if abs(w[1]) > 1e-9:
            ax.plot(x_edge, -(w[0]*x_edge + b)/w[1], 'k-', linewidth=1.5)
        for k in range(2):
            m = y == k
            ax.scatter(X[m,0], X[m,1], c=COLORS[k], marker=MARKERS[k],
                       s=45, edgecolors='k', linewidths=0.5)
        ax.set_xlim(-3, 3); ax.set_ylim(-3, 3)
        ax.set_title(f'Unit {i+1}  w={W2[i,0]:+.2f}')
    plt.suptitle(f'1-hidden-layer ReLU — epoch {frame*10} | acc {acc:.0%}'
                 '   [double-click any panel to focus]')

plt.animate(update, frames=100, interval=100)
plt.show()
"

Neural network training curves

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(1); losses, accs = [], []
def update(frame):
    t = frame/80
    losses.append(2.3*np.exp(-3*t)+0.08+0.03*np.random.randn())
    accs.append(min(0.99,1-np.exp(-4*t)*0.9+0.01*np.random.randn()))
    axs = plt.gcf().axes
    axs[0].cla(); axs[1].cla()
    axs[0].plot(losses,'b-',linewidth=2); axs[0].set_title('Loss'); axs[0].grid()
    axs[1].plot(accs,'g-',linewidth=2); axs[1].set_title('Accuracy'); axs[1].set_ylim(0,1); axs[1].grid()
plt.subplots(1,2,figsize=(10,4))
plt.animate(update, frames=80, interval=80); plt.show()
"

fill_between — confidence band widening under distribution shift

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(0)
x = np.linspace(0, 10, 80)
mean = np.sin(x) * np.exp(-x/8)
noise_levels = np.linspace(0.05, 0.6, 30)
def update(frame):
    sigma = noise_levels[frame]
    plt.cla()
    plt.plot(x, mean, 'steelblue', linewidth=2, label='prediction')
    plt.fill_between(x, mean - sigma, mean + sigma, alpha=0.35, color='steelblue', label=f'± {sigma:.2f}')
    plt.fill_between(x, mean - 2*sigma, mean + 2*sigma, alpha=0.15, color='steelblue', label='± 2σ')
    plt.ylim(-1.8, 1.8); plt.legend(); plt.grid()
    plt.title(f'Uncertainty grows under distribution shift — σ={sigma:.2f}')
plt.animate(update, frames=30, interval=150); plt.show()
"

errorbar — learning curve: accuracy rises, uncertainty shrinks with more data

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(0)
sizes = np.array([10, 25, 50, 100, 200, 400, 800])
means = 1 - 0.88*np.exp(-sizes/120) + 0.015*np.random.randn(len(sizes))
stds  = 0.32*np.exp(-sizes/80) + 0.01
def update(frame):
    n = frame + 1
    plt.cla()
    plt.errorbar(sizes[:n], means[:n], yerr=stds[:n], fmt='o-', capsize=5,
                 color='steelblue', label='accuracy ± std')
    plt.xlim(-30, 850); plt.ylim(0, 1.1)
    plt.xlabel('Training set size'); plt.ylabel('Accuracy')
    plt.title('Learning Curve — more data, less variance'); plt.legend(); plt.grid()
plt.animate(update, frames=len(sizes), interval=600); plt.show()
"

boxplot — prediction distribution tightens as model trains

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(1)
epochs = [5, 10, 20, 40, 80, 160]
data = [np.random.normal(0.35 + 0.55*(i/len(epochs)), max(0.28 - i*0.04, 0.04), 80)
        for i in range(len(epochs))]
def update(frame):
    n = frame + 1
    plt.cla()
    plt.boxplot(data[:n], labels=[str(e) for e in epochs[:n]])
    plt.ylim(-0.1, 1.1)
    plt.xlabel('Epoch'); plt.ylabel('Predicted probability')
    plt.title(f'Prediction Distribution — epoch {epochs[frame]}')
plt.animate(update, frames=len(epochs), interval=700); plt.show()
"

violinplot — activation distribution shifts as layers train

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(2)
steps = 6
data = [np.random.normal(i*0.5, max(1.1 - i*0.16, 0.15), 120) for i in range(steps)]
def update(frame):
    n = frame + 1
    plt.cla()
    plt.violinplot(data[:n], positions=list(range(1, n+1)), widths=0.7)
    plt.xlim(0, steps+1); plt.ylim(-3.5, 5.5)
    plt.xlabel('Training step'); plt.ylabel('Activation value')
    plt.title(f'Activation Distribution — step {frame+1} of {steps}')
plt.animate(update, frames=steps, interval=700); plt.show()
"

pie — class proportions shift as dataset is rebalanced

python3 -c "
import plotlive.pyplot as plt
labels = ['Negative', 'Neutral', 'Positive']
stages = [[70,20,10],[60,25,15],[50,30,20],[45,32,23],[40,35,25],[33,34,33]]
captions = ['raw','oversample pos','oversample more','near balance','balanced','uniform']
def update(frame):
    plt.cla()
    vals = stages[frame]
    plt.pie(vals, labels=labels, startangle=90)
    pcts = ' | '.join(f'{l}: {v}%' for l,v in zip(labels,vals))
    plt.title(f'Class Balance — {captions[frame]}\n{pcts}')
plt.animate(update, frames=len(stages), interval=900); plt.show()
"

stackplot — feature contributions accumulate as model complexity grows

python3 -c "
import plotlive.pyplot as plt, numpy as np
np.random.seed(3)
x = np.arange(20)
feats = ['linear','interactions','polynomials','residuals']
components = [np.abs(np.random.randn(20))*(i+1)*0.4 for i in range(len(feats))]
def update(frame):
    n = frame + 1
    plt.cla()
    plt.stackplot(x, *components[:n], labels=feats[:n], alpha=0.85)
    plt.xlim(0, 19); plt.ylim(0, sum(c.max() for c in components)*1.05)
    plt.xlabel('Sample'); plt.ylabel('Explained variance')
    plt.title(f'Model Complexity — adding {feats[frame]}')
    plt.legend()
plt.animate(update, frames=len(feats), interval=900); plt.show()
"

---

Sorting algorithm visualizations

Each opens its own window with 7 elements, a color legend, and step descriptions.

cd examples
python3 bubble_sort.py
python3 insertion_sort.py
python3 selection_sort.py
python3 heap_sort.py
python3 merge_sort.py
python3 quick_sort.py

Color	Meaning
Blue	Unsorted
Orange	Being compared
Red	Being swapped
Green	Confirmed sorted

Use ← / → to step frame by frame. The value of each element is shown below its bar.

Runtime benchmark — all 6 algorithms

python3 sort_benchmark.py

Benchmarks all 6 in the terminal first, then opens an animated log-scale line chart that reveals one input size at a time. Watch O(n²) and O(n log n) algorithms diverge as N grows.

---

Run tests

pytest tests/

Dependencies

• pygame-ce >= 2.4.0
• numpy >= 1.24.0
• Python 3.10+