plots added

This commit is contained in:
2025-09-24 16:04:42 -05:00
parent 555464f3cb
commit 4394d729b0
4 changed files with 241 additions and 0 deletions

1
.gitignore vendored
View File

@@ -9,3 +9,4 @@
**/*.bbl
**/**.dat
**/**.script
**/venv/**

140
plots/demo-plot-1/README.md Normal file
View File

@@ -0,0 +1,140 @@
# Parametric Surface Plotter
This project provides a simple way to **define and plot parametric 3D surfaces** (or curves) using Python.
* A **surface** is defined with **two parameters**:
$$
x = x(t, u), \quad y = y(t, u), \quad z = z(t, u)
$$
* A **curve** is defined with a **single parameter**:
$$
x = x(t), \quad y = y(t), \quad z = z(t)
$$
The script will:
* Generate a mesh of points (for surfaces) or a set of points (for curves)
* Plot the result in 3D with Matplotlib
* Save the plot as a high-definition `.svg` file, named after the parent directory of the script
---
## Requirements
Install dependencies:
```bash
pip install -r requirements.txt
```
---
## Usage
Run the script:
```bash
python plot_surface.py
```
A window with the 3D plot will open, and an `.svg` will be saved in the same directory.
---
## Defining Your Own Geometry
### 1. Surfaces (two parameters: t, u)
Surfaces require two parameters because they are 2D objects.
You define three functions in `plot_surface.py`:
```python
def x_func(t, u): return ...
def y_func(t, u): return ...
def z_func(t, u): return ...
```
Examples:
* **Cone**
$$
x = 4t\cos(u), \quad y = 4t\sin(u), \quad z = 10t
$$
```python
def x_func(t, u): return 4 * t * np.cos(u)
def y_func(t, u): return 4 * t * np.sin(u)
def z_func(t, u): return 10 * t
```
* **Sphere** (radius 1)
$$
x = \cos(u)\sin(t), \quad y = \sin(u)\sin(t), \quad z = \cos(t)
$$
```python
def x_func(t, u): return np.cos(u) * np.sin(t)
def y_func(t, u): return np.sin(u) * np.sin(t)
def z_func(t, u): return np.cos(t)
```
You can adjust parameter ranges in `generate_mesh()`:
```python
def generate_mesh(t_range=(0, 5), u_range=(0, 2*np.pi), n_t=50, n_u=100):
...
```
* Sphere → `t_range=(0, np.pi)`, `u_range=(0, 2*np.pi)`
* Cone → `t_range=(0, 5)`, `u_range=(0, 2*np.pi)`
---
### 2. Curves (one parameter: t)
If your object is not a surface but a **curve**, you only need one parameter $t$.
Example: **Helix**
$$
x = \cos(t), \quad y = \sin(t), \quad z = t
$$
```python
def x_func(t): return np.cos(t)
def y_func(t): return np.sin(t)
def z_func(t): return t
```
Here you dont need `u` at all. The code can be simplified to generate a 1D array of points and plot them as a line in 3D.
---
## Which Should I Use?
* **Two parameters (t, u):** Use this for **surfaces** (sphere, torus, cone, paraboloid, etc.).
* **One parameter (t):** Use this for **curves** (helix, circle, line, parametric trajectory).
👉 A quick rule:
* If your equation is like $z = f(x, y)$, or implicit in 3 variables, you usually need **two parameters**.
* If your equation is like $x = f(t), y = g(t), z = h(t)$, then **one parameter** is enough.
---
## Notes
* Always use `numpy` functions (`np.sin`, `np.cos`, etc.), not Pythons built-ins, since the parameters are arrays.
* Some surfaces (like cones, hyperboloids) have two branches; you can add an additional `z_func_neg` if needed.
* The SVG is automatically named after the scripts parent directory.
---
✅ With this, you can parametrize and visualize **both surfaces (2D)** and **curves (1D)** by editing only a few functions.

Binary file not shown.

After

Width:  |  Height:  |  Size: 18 MiB

100
plots/demo-plot-1/main.py Normal file
View File

@@ -0,0 +1,100 @@
import os
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D # needed for 3D plotting
from matplotlib import rcParams
# -------------------------------
# Parametric surface functions
# -------------------------------
def x_func(t, u):
"""Parametric x(t,u)"""
return 4 * t * np.cos(u)
def y_func(t, u):
"""Parametric y(t,u)"""
return 4 * t * np.sin(u)
def z_func(t, u):
"""Parametric z(t,u)"""
return 10 * t
def z_func_neg(t, u):
"""Optional lower branch"""
return -10 * t
# -------------------------------
# Generate mesh
# -------------------------------
def generate_mesh(t_range=(0, 5), u_range=(0, 2*np.pi), n_t=200, n_u=400):
"""High-resolution parametric mesh"""
t = np.linspace(t_range[0], t_range[1], n_t)
u = np.linspace(u_range[0], u_range[1], n_u)
T, U = np.meshgrid(t, u)
X = x_func(T, U)
Y = y_func(T, U)
Z1 = z_func(T, U)
Z2 = z_func_neg(T, U)
return X, Y, Z1, Z2
# -------------------------------
# Plot surface with high-quality settings
# -------------------------------
def plot_surface():
# Generate high-res mesh
X, Y, Z1, Z2 = generate_mesh()
# Create figure with high DPI
fig = plt.figure(figsize=(12, 10), dpi=600)
ax = fig.add_subplot(111, projection="3d")
# Smooth shading, anti-aliasing
surf1 = ax.plot_surface(
X, Y, Z1,
cmap="viridis",
edgecolor="none",
rstride=1,
cstride=1,
antialiased=True,
linewidth=0,
alpha=0.95
)
surf2 = ax.plot_surface(
X, Y, Z2,
cmap="viridis",
edgecolor="none",
rstride=1,
cstride=1,
antialiased=True,
linewidth=0,
alpha=0.95
)
# Axis labels and title
ax.set_xlabel("X", labelpad=15)
ax.set_ylabel("Y", labelpad=15)
ax.set_zlabel("Z", labelpad=15)
ax.set_title("Parametric Surface", pad=20)
# Optional: adjust viewing angle
ax.view_init(elev=30, azim=45)
# Add colorbar
fig.colorbar(surf1, shrink=0.5, aspect=10, pad=0.1)
# Save at maximum quality
parent_dir = os.path.basename(os.path.dirname(os.path.abspath(__file__)))
filename_png = f"{parent_dir}.png"
plt.savefig(filename_png, format="png", dpi=1200, bbox_inches='tight') # ultra-high-res raster
print(f"and PNG as {filename_png}")
# Show interactive window (optional)
# -------------------------------
# Main
# -------------------------------
if __name__ == "__main__":
plot_surface()