REFERENSI CEPAT MATPLOTLIB
Figure, axes, plot, dan kustomisasi
Plot Dasar
Line Plot
import matplotlib.pyplot as plt
x = [1, 2, 3, 4, 5]
y = [2, 4, 1, 8, 3]
plt.plot(x, y)
plt.show()
Pintasan Plot Cepat
plt.plot(y) # x auto 0..N-1
plt.plot(x, y, "ro--") # red circles, dashed
plt.plot(x, y, "bs-") # blue squares, solid
Kode Format String
| `r` `g` `b` `k` | Merah, hijau, biru, hitam |
| `o` `s` `^` `D` | Marker lingkaran, kotak, segitiga, berlian |
| `-` `--` `-.` `:` | Garis solid, putus-putus, titik-putus, titik-titik |
Subplot
Figure dan Axes
fig, ax = plt.subplots()
ax.plot(x, y)
ax.set_title("Single Plot")
plt.show()
Grid Subplot
fig, axes = plt.subplots(2, 2, figsize=(8, 6))
axes[0, 0].plot(x, y)
axes[0, 1].bar(x, y)
axes[1, 0].scatter(x, y)
fig.tight_layout()
Axes Berbagi
fig, (ax1, ax2) = plt.subplots(1, 2,
sharey=True, figsize=(10, 4))
ax1.plot(x, y)
ax2.plot(x, y2)
Label & Judul
Label Sumbu dan Judul
plt.plot(x, y)
plt.xlabel("Time (s)")
plt.ylabel("Value")
plt.title("Sensor Reading")
plt.show()
Label Gaya OO
fig, ax = plt.subplots()
ax.plot(x, y)
ax.set_xlabel("X"); ax.set_ylabel("Y")
ax.set_title("My Plot")
Anotasi
ax.annotate("Peak", xy=(4, 8),
xytext=(3, 9),
arrowprops=dict(arrowstyle="->"))
Kustomisasi
Warna dan Gaya
plt.plot(x, y, color="#FF5733",
linewidth=2, linestyle="--")
plt.plot(x, y2, color="steelblue",
marker="o", markersize=5)
Ukuran Figure dan DPI
fig, ax = plt.subplots(figsize=(10, 6), dpi=100)
plt.rcParams["figure.figsize"] = (8, 5)
Lembar Gaya
print(plt.style.available) # list all
plt.style.use("seaborn-v0_8")
plt.style.use("ggplot")
Batang & Histogram
Diagram Batang
labels = ["A", "B", "C", "D"]
values = [23, 45, 12, 37]
plt.bar(labels, values, color="teal")
plt.show()
Batang Berkelompok / Bertumpuk
import numpy as np
x = np.arange(4); w = 0.35
plt.bar(x - w/2, v1, w, label="2024")
plt.bar(x + w/2, v2, w, label="2025")
plt.xticks(x, labels)
Histogram
data = np.random.randn(1000)
plt.hist(data, bins=30, edgecolor="black",
alpha=0.7)
plt.show()
Sebar & Garis
Plot Sebar
plt.scatter(x, y, c="red", s=50,
alpha=0.6, edgecolors="black")
plt.show()
Sebar dengan Colormap
sc = plt.scatter(x, y, c=values,
cmap="viridis", s=sizes)
plt.colorbar(sc, label="Intensity")
Beberapa Garis
plt.plot(x, y1, label="Train")
plt.plot(x, y2, label="Validation")
plt.legend()
plt.show()
Axes & Tanda Sumbu
Batas dan Skala Sumbu
ax.set_xlim(0, 10)
ax.set_ylim(-1, 1)
ax.set_xscale("log")
ax.set_yscale("log")
Tanda Sumbu Custom
ax.set_xticks([0, 1, 2, 3, 4])
ax.set_xticklabels(["Mon", "Tue", "Wed",
"Thu", "Fri"], rotation=45)
Grid
ax.grid(True, linestyle="--", alpha=0.5)
ax.grid(axis="y") # horizontal only
Legenda
Menambahkan Legenda
ax.plot(x, y, label="Series A")
ax.plot(x, y2, label="Series B")
ax.legend(loc="upper right")
Penempatan Legenda
| `'best'` | Posisi terbaik otomatis (default) |
| `'upper left'` | Pojok kiri atas |
| `'lower right'` | Pojok kanan bawah |
| `'center'` | Tengah axes |
| `bbox_to_anchor=(1, 1)` | Tempatkan di luar area axes |
Kustomisasi Legenda
ax.legend(fontsize=8, frameon=False,
ncol=2, title="Legend")
Menyimpan
Simpan ke File
plt.savefig("plot.png", dpi=300,
bbox_inches="tight")
plt.savefig("plot.pdf")
plt.savefig("plot.svg", transparent=True)
Format yang Didukung
| PNG | Raster, terbaik untuk web/layar |
| PDF | Vektor, terbaik untuk cetak/makalah |
| SVG | Vektor, skalabel untuk web |
| EPS | Vektor, jurnal ilmiah lama |
Simpan dari Objek Figure
fig, ax = plt.subplots()
ax.plot(x, y)
fig.savefig("output.png", dpi=150,
facecolor="white")
Pola Umum
Twin Axes (Dua Skala Y)
fig, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax1.plot(x, temp, "r-", label="Temp")
ax2.plot(x, pressure, "b-", label="Pressure")
Fill Between
ax.fill_between(x, y_low, y_high,
alpha=0.3, color="blue")
Heatmap dengan imshow
data = np.random.rand(10, 10)
plt.imshow(data, cmap="hot",
interpolation="nearest")
plt.colorbar()
Diagram Lingkaran
plt.pie(sizes, labels=labels,
autopct="%1.1f%%", startangle=90)
plt.axis("equal")