# Color Several Lines
# ===================

# Render several `pyvista.MultipleLines()` polylines and color them by a
# line-wise scalar value.
import numpy as np
import pyvista as pv

# Build a small family of curves
# ==============================

# Each curve carries a single `line_id` cell scalar so the merged dataset
# can be colored line-by-line.
lines = []
for index, phase in enumerate(np.linspace(0, np.pi, 4)):
    t = np.linspace(0, 1, 80)
    points = np.column_stack(
        (
            4 * t - 2,
            np.sin(2 * np.pi * t + phase),
            0.4 * np.cos(np.pi * t + phase),
        ),
    )
    line = pv.MultipleLines(points)
    line.cell_data['line_id'] = np.array([index])
    lines.append(line)

curves = pv.merge(lines)
curves

# Tube and color the lines
# ========================

# Coloring by `line_id` gives each line a single uniform color.
pl = pv.Plotter()
pl.add_mesh(
    curves.tube(radius=0.06),
    scalars='line_id',
    cmap='viridis',
    show_scalar_bar=False,
)
pl.show()

# ----------------------------------------------------------------------
# Generated by sphinx-examples-as-code https://github.com/pyvista/sphinx-examples-as-code