diff --git a/meteoinfo-lab/milconfig.xml b/meteoinfo-lab/milconfig.xml
index 203e089b..61e3c364 100644
--- a/meteoinfo-lab/milconfig.xml
+++ b/meteoinfo-lab/milconfig.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <MeteoInfo File="milconfig.xml" Type="configurefile">
-  <Path OpenPath="D:\Working\MIScript\Jython\mis\common_math\optimize">
+  <Path OpenPath="D:\Working\MIScript\Jython\mis\array">
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\plot_types\3d"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\test"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\plot_types\3d\jogl"/>
@@ -12,21 +12,23 @@
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\io\geotiff"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\plot_types"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\plot_types\bar"/>
-    <RecentFolder Folder="D:\Working\MIScript\Jython\mis"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\common_math"/>
-    <RecentFolder Folder="D:\Working\MIScript\Jython\mis\array"/>
     <RecentFolder Folder="D:\Working\MIScript\Jython\mis\common_math\optimize"/>
+    <RecentFolder Folder="D:\Working\MIScript\Jython\mis"/>
+    <RecentFolder Folder="D:\Working\MIScript\Jython\mis\array"/>
   </Path>
   <File>
     <OpenedFiles>
       <OpenedFile File="D:\Working\MIScript\Jython\mis\toolbox\miml\cluster\dbscan_1.py"/>
       <OpenedFile File="D:\Working\MIScript\Jython\mis\plot_types\bar\bar_hatch.py"/>
       <OpenedFile File="D:\Working\MIScript\Jython\mis\common_math\optimize\fixed_point.py"/>
+      <OpenedFile File="D:\Working\MIScript\Jython\mis\array\masked_array_1.py"/>
     </OpenedFiles>
     <RecentFiles>
       <RecentFile File="D:\Working\MIScript\Jython\mis\toolbox\miml\cluster\dbscan_1.py"/>
       <RecentFile File="D:\Working\MIScript\Jython\mis\plot_types\bar\bar_hatch.py"/>
       <RecentFile File="D:\Working\MIScript\Jython\mis\common_math\optimize\fixed_point.py"/>
+      <RecentFile File="D:\Working\MIScript\Jython\mis\array\masked_array_1.py"/>
     </RecentFiles>
   </File>
   <Font>
@@ -34,5 +36,5 @@
   </Font>
   <LookFeel DockWindowDecorated="true" LafDecorated="true" Name="FlatDarkLaf"/>
   <Figure DoubleBuffering="true"/>
-  <Startup MainFormLocation="-7,-7" MainFormSize="1293,693"/>
+  <Startup MainFormLocation="-7,0" MainFormSize="1380,813"/>
 </MeteoInfo>
diff --git a/meteoinfo-lab/pylib/mipylib/meteolib/calc/tools.py b/meteoinfo-lab/pylib/mipylib/meteolib/calc/tools.py
index eae2014d..c874c960 100644
--- a/meteoinfo-lab/pylib/mipylib/meteolib/calc/tools.py
+++ b/meteoinfo-lab/pylib/mipylib/meteolib/calc/tools.py
@@ -1,5 +1,48 @@
 import mipylib.numeric as np
 
+def resample_nn_1d(a, centers):
+    """Return one-dimensional nearest-neighbor indexes based on user-specified centers.
+    Parameters
+    ----------
+    a : array-like
+        1-dimensional array of numeric values from which to extract indexes of
+        nearest-neighbors
+    centers : array-like
+        1-dimensional array of numeric values representing a subset of values to approximate
+    Returns
+    -------
+        A list of indexes (in type given by `array.argmin()`) representing values closest to
+        given array values.
+    """
+    ix = []
+    for center in centers:
+        index = (np.abs(a - center)).argmin()
+        if index not in ix:
+            ix.append(index)
+    return ix
+
+def nearest_intersection_idx(a, b):
+    """Determine the index of the point just before two lines with common x values.
+    Parameters
+    ----------
+    a : array-like
+        1-dimensional array of y-values for line 1
+    b : array-like
+        1-dimensional array of y-values for line 2
+    Returns
+    -------
+        An array of indexes representing the index of the values
+        just before the intersection(s) of the two lines.
+    """
+    # Difference in the two y-value sets
+    difference = a - b
+
+    # Determine the point just before the intersection of the lines
+    # Will return multiple points for multiple intersections
+    sign_change_idx, = np.nonzero(np.diff(np.sign(difference)))
+
+    return sign_change_idx
+
 def _remove_nans(*variables):
     """Remove NaNs from arrays that cause issues with calculations.
     Takes a variable number of arguments and returns masked arrays in the same
diff --git a/meteoinfo-lab/pylib/mipylib/numeric/__init__$py.class b/meteoinfo-lab/pylib/mipylib/numeric/__init__$py.class
index 05c75087..d41ec291 100644
Binary files a/meteoinfo-lab/pylib/mipylib/numeric/__init__$py.class and b/meteoinfo-lab/pylib/mipylib/numeric/__init__$py.class differ
diff --git a/meteoinfo-lab/pylib/mipylib/numeric/__init__.py b/meteoinfo-lab/pylib/mipylib/numeric/__init__.py
index 2268c9c4..40ab03d5 100644
--- a/meteoinfo-lab/pylib/mipylib/numeric/__init__.py
+++ b/meteoinfo-lab/pylib/mipylib/numeric/__init__.py
@@ -4,6 +4,7 @@ from . import lib
 from .lib import *
 from . import linalg
 from . import random
+from . import ma
 from . import fitting
 from . import stats
 from . import interpolate
@@ -17,6 +18,6 @@ __all__ = []
 __all__.extend(['__version__'])
 __all__.extend(core.__all__)
 __all__.extend(lib.__all__)
-__all__.extend(['linalg', 'fitting', 'random', 'stats', 'interpolate', 'optimize', 'signal', 'spatial',
+__all__.extend(['linalg', 'fitting', 'random', 'ma', 'stats', 'interpolate', 'optimize', 'signal', 'spatial',
                 'special'])
 __all__.extend(['griddata'])
\ No newline at end of file
diff --git a/meteoinfo-lab/pylib/mipylib/numeric/ma/__init__.py b/meteoinfo-lab/pylib/mipylib/numeric/ma/__init__.py
new file mode 100644
index 00000000..692f3c69
--- /dev/null
+++ b/meteoinfo-lab/pylib/mipylib/numeric/ma/__init__.py
@@ -0,0 +1 @@
+from .core import masked_array, MaskedArray
\ No newline at end of file
diff --git a/meteoinfo-lab/pylib/mipylib/numeric/ma/core.py b/meteoinfo-lab/pylib/mipylib/numeric/ma/core.py
new file mode 100644
index 00000000..5fd0a281
--- /dev/null
+++ b/meteoinfo-lab/pylib/mipylib/numeric/ma/core.py
@@ -0,0 +1,165 @@
+from mipylib import numeric as np
+from ..core._ndarray import NDArray
+from org.meteoinfo.ndarray.math import ArrayUtil
+
+nomask = False
+
+class MaskedArray(NDArray):
+    """
+    An array class with possibly masked values.
+    Masked values of True exclude the corresponding element from any
+    computation.
+    Construction::
+      x = MaskedArray(data, mask=nomask, dtype=None, copy=False, subok=True,
+                      ndmin=0, fill_value=None, keep_mask=True, hard_mask=None,
+                      shrink=True, order=None)
+    Parameters
+    ----------
+    data : array_like
+        Input data.
+    mask : sequence, optional
+        Mask. Must be convertible to an array of booleans with the same
+        shape as `data`. True indicates a masked (i.e. invalid) data.
+    dtype : dtype, optional
+        Data type of the output.
+        If `dtype` is None, the type of the data argument (``data.dtype``)
+        is used. If `dtype` is not None and different from ``data.dtype``,
+        a copy is performed.
+    copy : bool, optional
+        Whether to copy the input data (True), or to use a reference instead.
+        Default is False.
+    subok : bool, optional
+        Whether to return a subclass of `MaskedArray` if possible (True) or a
+        plain `MaskedArray`. Default is True.
+    ndmin : int, optional
+        Minimum number of dimensions. Default is 0.
+    fill_value : scalar, optional
+        Value used to fill in the masked values when necessary.
+        If None, a default based on the data-type is used.
+    """
+
+    def __init__(self, data, mask=nomask, dtype=None, copy=False,
+                 subok=True, ndmin=0, fill_value=None):
+        if isinstance(data, NDArray):
+            data = data._array
+        super(MaskedArray, self).__init__(data)
+        self._data = NDArray(self._array)
+        self._baseclass = getattr(data, '_baseclass', type(self._data))
+        if mask is nomask:
+            self._mask = mask
+        else:
+            self._mask = np.array(mask)
+            if self._mask.shape != self._data.shape:
+                self._mask = self._mask.reshape(self._data.shape)
+            if self._mask.dtype != np.dtype.bool:
+                self._mask = self._mask.astype(np.dtype.bool)
+        self._fill_value = fill_value
+
+    def __str__(self):
+        r = 'masked_array(data=' + ArrayUtil.convertToString(self._data._array) + ',\n\tmask='
+        if self._mask is nomask:
+            r = r + 'False,'
+        else:
+            r = r + ArrayUtil.convertToString(self._mask._array) + ','
+        r = r + '\n\tfill_value=' + str(self._fill_value) + ')'
+        return r
+
+    def __repr__(self):
+        return self.__str__()
+
+    def filled(self, fill_value=None):
+        """
+        Return a copy of self, with masked values filled with a given value.
+        **However**, if there are no masked values to fill, self will be
+        returned instead as an ndarray.
+        Parameters
+        ----------
+        fill_value : array_like, optional
+            The value to use for invalid entries. Can be scalar or non-scalar.
+            If non-scalar, the resulting ndarray must be broadcastable over
+            input array. Default is None, in which case, the `fill_value`
+            attribute of the array is used instead.
+        Returns
+        -------
+        filled_array : ndarray
+            A copy of ``self`` with invalid entries replaced by *fill_value*
+            (be it the function argument or the attribute of ``self``), or
+            ``self`` itself as an ndarray if there are no invalid entries to
+            be replaced.
+        Notes
+        -----
+        The result is **not** a MaskedArray!
+        Examples
+        --------
+        >>> x = np.ma.array([1,2,3,4,5], mask=[0,0,1,0,1], fill_value=-999)
+        >>> x.filled()
+        array([   1,    2, -999,    4, -999])
+        >>> x.filled(fill_value=1000)
+        array([   1,    2, 1000,    4, 1000])
+        >>> type(x.filled())
+        <class 'numpy.ndarray'>
+        Subclassing is preserved. This means that if, e.g., the data part of
+        the masked array is a recarray, `filled` returns a recarray:
+        >>> x = np.array([(-1, 2), (-3, 4)], dtype='i8,i8').view(np.recarray)
+        >>> m = np.ma.array(x, mask=[(True, False), (False, True)])
+        >>> m.filled()
+        rec.array([(999999,      2), (    -3, 999999)],
+                  dtype=[('f0', '<i8'), ('f1', '<i8')])
+        """
+        m = self._mask
+        if m is nomask:
+            return self._data
+
+        if fill_value is None:
+            fill_value = self._fill_value
+
+        result = self._data.copy()
+        result[m] = fill_value
+        return result
+
+    def sum(self, axis=None):
+        """
+        Sum of array elements over a given axis.
+
+        :param axis: (*int*) Axis along which the standard deviation is computed.
+            The default is to compute the standard deviation of the flattened array.
+
+        returns: (*array_like*) Sum result.
+        """
+        if self._mask is nomask:
+            return self._data.sum(axis=axis)
+        else:
+            r = self.filled(0)
+            return r.sum(axis=axis)
+
+    def count(self, axis=None):
+        """
+        Count of valid array elements over a given axis.
+
+        :param axis: (*int*) Axis along which the standard deviation is computed.
+            The default is to compute the standard deviation of the flattened array.
+        :return: (*array_like*) Count result.
+        """
+        if self._mask is nomask:
+            mask = np.ones(self._data.shape)
+            return mask.sum(axis=axis)
+        else:
+            return (~self._mask).sum(axis=axis)
+
+    def mean(self, axis=None):
+        """
+        Compute tha arithmetic mean along the specified axis.
+
+        :param axis: (*int*) Axis along which the value is computed.
+            The default is to compute the value of the flattened array.
+
+        returns: (*array_like*) Mean result
+        """
+        if self._mask is nomask:
+            return self._data.mean(axis=axis)
+        else:
+            dsum = self.sum(axis=axis)
+            cnt = self.count(axis=axis)
+            return dsum * 1. / cnt
+
+masked_array = MaskedArray
\ No newline at end of file
diff --git a/meteoinfo-ndarray/src/main/java/org/meteoinfo/ndarray/math/ArrayMath.java b/meteoinfo-ndarray/src/main/java/org/meteoinfo/ndarray/math/ArrayMath.java
index a4667996..2ce4f5e3 100644
--- a/meteoinfo-ndarray/src/main/java/org/meteoinfo/ndarray/math/ArrayMath.java
+++ b/meteoinfo-ndarray/src/main/java/org/meteoinfo/ndarray/math/ArrayMath.java
@@ -7763,6 +7763,7 @@ public class ArrayMath {
         Number n = new Double(v);
         switch (dt) {
             case INT:
+            case BOOLEAN:
                 return n.intValue();
             case FLOAT:
                 return n.floatValue();