DOC: Add example for np.ma.compressed. (#23426)

* DOC: Add example to np.ma.compressed().

* Update example.

* Update core.py

1 files changed, 23 insertions, 0 deletions

diff --git a/numpy/ma/core.py b/numpy/ma/core.py
index dcec82773..7f57985a9 100644
--- a/numpy/ma/core.py
+++ b/numpy/ma/core.py
@@ -7033,6 +7033,29 @@ def compressed(x):
     --------
     ma.MaskedArray.compressed : Equivalent method.
 
+    Examples
+    --------
+    
+    Create an array with negative values masked:
+
+    >>> import numpy as np
+    >>> x = np.array([[1, -1, 0], [2, -1, 3], [7, 4, -1]])
+    >>> masked_x = np.ma.masked_array(x, mask=x < 0)
+    >>> masked_x
+    masked_array(
+      data=[[1, --, 0],
+            [2, --, 3],
+            [7, 4, --]],
+      mask=[[False,  True, False],
+            [False,  True, False],
+            [False, False,  True]],
+      fill_value=999999)
+
+    Compress the masked array into a 1-D array of non-masked values:
+
+    >>> np.ma.compressed(masked_x)
+    array([1, 0, 2, 3, 7, 4])
+
     """
     return asanyarray(x).compressed()