code: def test_andrews_curves():
      data = pd.DataFrame(
          {
              "x": range(10),
              "y": range(10),
              "z": range(10),
              "c": list("ABABABABAB"),
          }
      )
      n_samples = 120
      n_points = len(data)
      plot = pdvega.andrews_curves(data, "c", samples=120, alpha=0.5)
      utils.validate_vegalite(plot)
      utils.check_encodings(
          plot,
          x="t",
          y=" ",
          color="c",
          detail="sample",
          opacity=utils.IGNORE,
      )
  
      spec = plot.to_dict()
      enc = spec["encoding"]
      assert spec["mark"] == "line"
      assert enc["x"]["type"] == "quantitative"
      assert enc["y"]["type"] == "quantitative"
      assert enc["color"]["type"] == "nominal"
      assert enc["detail"]["type"] == "quantitative"
      assert enc["opacity"]["value"] == 0.5
  
      df = utils.get_data(plot)
      assert len(df) == n_samples * n_points
  
file_path: pdvega/pdvega/tests/test_plotting.py
imports: import pytest
  import numpy
  import pandas
  import pdvega
  from pdvega.tests import utils
label_desc: Use image node_id 3 for calling a global function with example usage: test_andrews_curves() without return types