Skip to main content

sample_points()

Sample mesh data at multiple point coordinates (point cloud).

This method creates a point cloud probe from the specified coordinates and samples the mesh data onto each point. For temporal datasets, automatically sweeps all time points unless time_value is specified. For static datasets, returns values directly.

Parameters

  • points (Sequence[Sequence[float]]) — List of 3D coordinates [[x, y, z], ...] to sample at.

  • time_value (float | None, default: None) — Query a specific time value instead of sweeping all time points. Ignored for static datasets.

  • tolerance (float | None, default: None) — Tolerance for the sample operation. If None, PyVista generates a tolerance automatically.

  • progress_callback (callable | None, default: None) — Callback function for progress updates during temporal sweeps. Called with (current, total). Should return True to continue or False to cancel.

Returns

Returns a list of dictionaries (one per point) with array names as keys. Each dictionary includes a "coordinates" key with the probe position.

[
    {
        "scalar_name": {
            "time": [0.0, 0.001, 0.002, ...],
            "value": [val0, val1, val2, ...]
        },
        "coordinates": {"x": 1.0, "y": 2.0, "z": 3.0},
        ...
    },
    {
        "scalar_name": {
            "time": [0.0, 0.001, 0.002, ...],
            "value": [val0, val1, val2, ...]
        },
        "coordinates": {"x": 4.0, "y": 5.0, "z": 6.0},
        ...
    },
    ...
]

Examples​

Sweep all time steps​

from pyemsi import Plotter, examples
from matplotlib import pyplot

file_path = examples.transient_path()
plt = Plotter(file_path)

data = plt.sample_points([(0.02, 0.02, 0.05), (0.02, 0.02, 0.02), (0.02, 0.02, 0.07)])

fig, ax = pyplot.subplots()
ax.plot(data[0]["B-Mag (T)"]["time"], data[0]["B-Mag (T)"]["value"], marker="o", label="Point (0.02, 0.02, 0.05)")
ax.plot(data[1]["B-Mag (T)"]["time"], data[1]["B-Mag (T)"]["value"], marker="o", label="Point (0.02, 0.02, 0.02)")
ax.plot(data[2]["B-Mag (T)"]["time"], data[2]["B-Mag (T)"]["value"], marker="o", label="Point (0.02, 0.02, 0.07)")
ax.set_xlabel("Time (s)")
ax.set_ylabel("B-Mag (T)")
ax.set_title("B-Mag (T) at Sampled Points")
ax.legend()
fig.tight_layout()
fig.savefig("docs/static/demos/sample_points.png")

Sample Points

Query a single time value​

from pyemsi import Plotter, examples

file_path = examples.transient_path()
plt = Plotter(file_path)

# Use time_point_value() to look up the time value for a given index
t = plt.time_point_value(4)   # 0.05  (5th time step, zero-based)

# Sample only at that time value instead of sweeping all time steps
data = plt.sample_points([(0.02, 0.02, 0.05), (0.02, 0.02, 0.02), (0.02, 0.02, 0.07)], time_value=t)

print(data[0]["B-Mag (T)"]["time"])   # [0.05]
print(data[0]["B-Mag (T)"]["value"])  # [0.08909410238265991]
print(data[1]["B-Mag (T)"]["value"])  # [0.10839000344276428]
print(data[2]["B-Mag (T)"]["value"])  # [0.06968670338392258]

See Also​