Wrap grd2xyz

doc/api/index.rst

@@ -88,6 +88,7 @@ Operations on grids:
 .. autosummary::
     :toctree: generated
 
+    grd2xyz
     grdclip
     grdcut
     grdfill

pygmt/__init__.py

@@ -33,6 +33,7 @@
     blockmedian,
     config,
     grd2cpt,
+    grd2xyz,
     grdclip,
     grdcut,
     grdfill,

pygmt/src/__init__.py

@@ -10,6 +10,7 @@
 from pygmt.src.config import config
 from pygmt.src.contour import contour
 from pygmt.src.grd2cpt import grd2cpt
+from pygmt.src.grd2xyz import grd2xyz
 from pygmt.src.grdclip import grdclip
 from pygmt.src.grdcontour import grdcontour
 from pygmt.src.grdcut import grdcut

pygmt/src/grd2xyz.py

@@ -0,0 +1,53 @@
+"""
+grd2xyz - Convert grid to data table
+"""
+from pygmt.clib import Session
+from pygmt.helpers import (
+    GMTTempFile,
+    build_arg_string,
+    fmt_docstring,
+    kwargs_to_strings,
+    use_alias,
+)
+
+
+@fmt_docstring
+@use_alias(
+    R="region",
+    V="verbose",
+)
+@kwargs_to_strings(R="sequence")
+def grd2xyz(grid, **kwargs):
+    r"""
+    Create xyz tables from grid files.
+
+    Read a binary 2-D grid files and write out
+    xyz-triplets in ASCII [or binary] format to a standard output.
+
+    Full option list at :gmt-docs:`grd2xyz.html`
+
+    {aliases}
+
+    Parameters
+    ----------
+    grid : str or xarray.DataArray
+        The file name of the input grid or the grid loaded as a DataArray.
+        This is the only required parameter.
+    {R}
+    {V}
+
+    Returns
+    -------
+    info : str
+        A string with information about the grid.
+    """
+    with GMTTempFile() as outfile:
+        with Session() as lib:
+            file_context = lib.virtualfile_from_data(check_kind="raster", data=grid)
+            with file_context as infile:
+                arg_str = " ".join(
+                    [infile, build_arg_string(kwargs), "->" + outfile.name]
+                )
+                lib.call_module("grd2xyz", arg_str)
+        result = outfile.read()
+    return result

pygmt/tests/test_grd2xyz.py

@@ -0,0 +1,27 @@
+"""
+Tests for grd2xyz.
+"""
+import pytest
+from pygmt import grd2xyz
+from pygmt.datasets import load_earth_relief
+
+
+@pytest.fixture(scope="module", name="grid")
+def fixture_grid():
+    """
+    Load the grid data from the sample earth_relief file.
+    """
+    return load_earth_relief(resolution="01d", region=[-1, 1, -1, 1])
+
+
+def test_grd2xyz(grid):
+    """
+    Make sure grd2xyz works as expected.
+    """
+    xyz_data = grd2xyz(grid=grid)
+    assert xyz_data.strip().split("\n") == [
+        "-0.5 0.5 -4967",
+        "0.5 0.5 -4852",
+        "-0.5 -0.5 -4917",
+        "0.5 -0.5 -4747.5",
+    ]