From 0d24a3508b467236717ce5f54c4bbf41ffe95456 Mon Sep 17 00:00:00 2001
From: Dongdong Tian <seisman.info@gmail.com>
Date: Wed, 13 Mar 2024 21:53:25 +0800
Subject: [PATCH] pygmt.triangulate.delaunay_triples: Add 'output_type'
 parameter for output in pandas/numpy/file formats

---
 pygmt/src/triangulate.py        | 59 ++++++++++++---------------------
 pygmt/tests/test_triangulate.py | 22 ------------
 2 files changed, 22 insertions(+), 59 deletions(-)

diff --git a/pygmt/src/triangulate.py b/pygmt/src/triangulate.py
index e73ab92fe5e..ba93800ece9 100644
--- a/pygmt/src/triangulate.py
+++ b/pygmt/src/triangulate.py
@@ -3,6 +3,9 @@
 Cartesian data.
 """
 
+from typing import Literal
+
+import numpy as np
 import pandas as pd
 from pygmt.clib import Session
 from pygmt.helpers import (
@@ -172,10 +175,10 @@ def delaunay_triples(
         y=None,
         z=None,
         *,
-        output_type="pandas",
-        outfile=None,
+        output_type: Literal["pandas", "numpy", "file"] = "pandas",
+        outfile: str | None = None,
         **kwargs,
-    ):
+    ) -> pd.DataFrame | np.ndarray | None:
         """
         Delaunay triangle based gridding of Cartesian data.
 
@@ -204,16 +207,8 @@ def delaunay_triples(
             {table-classes}.
         {projection}
         {region}
-        outfile : str or None
-            The name of the output ASCII file to store the results of the
-            histogram equalization in.
-        output_type : str
-            Determine the format the xyz data will be returned in [Default is
-            ``pandas``]:
-
-                - ``numpy`` - :class:`numpy.ndarray`
-                - ``pandas``- :class:`pandas.DataFrame`
-                - ``file`` - ASCII file (requires ``outfile``)
+        {output_type}
+        {outfile}
         {verbose}
         {binary}
         {nodata}
@@ -226,13 +221,13 @@ def delaunay_triples(
 
         Returns
         -------
-        ret : pandas.DataFrame or numpy.ndarray or None
+        ret
             Return type depends on ``outfile`` and ``output_type``:
 
             - None if ``outfile`` is set (output will be stored in file set by
               ``outfile``)
-            - :class:`pandas.DataFrame` or :class:`numpy.ndarray` if
-              ``outfile`` is not set (depends on ``output_type``)
+            - :class:`pandas.DataFrame` or :class:`numpy.ndarray` if ``outfile`` is not
+              set (depends on ``output_type``)
 
         Note
         ----
@@ -243,25 +238,15 @@ def delaunay_triples(
         """
         output_type = validate_output_table_type(output_type, outfile)
 
-        with GMTTempFile(suffix=".txt") as tmpfile:
-            with Session() as lib:
-                with lib.virtualfile_in(
+        with Session() as lib:
+            with (
+                lib.virtualfile_in(
                     check_kind="vector", data=data, x=x, y=y, z=z, required_z=False
-                ) as vintbl:
-                    if outfile is None:
-                        outfile = tmpfile.name
-                    lib.call_module(
-                        module="triangulate",
-                        args=build_arg_string(kwargs, infile=vintbl, outfile=outfile),
-                    )
-
-            if outfile == tmpfile.name:
-                # if user did not set outfile, return pd.DataFrame
-                result = pd.read_csv(outfile, sep="\t", header=None)
-            elif outfile != tmpfile.name:
-                # return None if outfile set, output in outfile
-                result = None
-
-            if output_type == "numpy":
-                result = result.to_numpy()
-        return result
+                ) as vintbl,
+                lib.virtualfile_out(kind="dataset", fname=outfile) as vouttbl,
+            ):
+                lib.call_module(
+                    module="triangulate",
+                    args=build_arg_string(kwargs, infile=vintbl, outfile=vouttbl),
+                )
+            return lib.virtualfile_to_dataset(output_type=output_type, vfile=vouttbl)
diff --git a/pygmt/tests/test_triangulate.py b/pygmt/tests/test_triangulate.py
index 154bc82b09f..c4fbf371721 100644
--- a/pygmt/tests/test_triangulate.py
+++ b/pygmt/tests/test_triangulate.py
@@ -106,28 +106,6 @@ def test_delaunay_triples_ndarray_output(dataframe, expected_dataframe):
     np.testing.assert_allclose(actual=output, desired=expected_dataframe.to_numpy())
 
 
-def test_delaunay_triples_outfile(dataframe, expected_dataframe):
-    """
-    Test triangulate.delaunay_triples with ``outfile``.
-    """
-    with GMTTempFile(suffix=".txt") as tmpfile:
-        with pytest.warns(RuntimeWarning) as record:
-            result = triangulate.delaunay_triples(data=dataframe, outfile=tmpfile.name)
-            assert len(record) == 1  # check that only one warning was raised
-        assert result is None  # return value is None
-        assert Path(tmpfile.name).stat().st_size > 0
-        temp_df = pd.read_csv(filepath_or_buffer=tmpfile.name, sep="\t", header=None)
-        pd.testing.assert_frame_equal(left=temp_df, right=expected_dataframe)
-
-
-def test_delaunay_triples_invalid_format(dataframe):
-    """
-    Test that triangulate.delaunay_triples fails with incorrect format.
-    """
-    with pytest.raises(GMTInvalidInput):
-        triangulate.delaunay_triples(data=dataframe, output_type=1)
-
-
 @pytest.mark.benchmark
 def test_regular_grid_no_outgrid(dataframe, expected_grid):
     """