Rename nabla -> laplacian

pina/equation/equation_factory.py

@@ -1,6 +1,6 @@
 """ Module """
 from .equation import Equation
-from ..operators import grad, div, nabla
+from ..operators import grad, div, laplacian
 
 
 class FixedValue(Equation):
@@ -92,5 +92,5 @@ class Laplace(Equation):
             are considered. Default is ``None``.
         """     
         def equation(input_, output_):
-            return nabla(output_, input_, components=components, d=d)
-        super().__init__(equation)
+            return laplacian(output_, input_, components=components, d=d)
+        super().__init__(equation)

pina/operators.py

@@ -145,26 +145,26 @@ def div(output_, input_, components=None, d=None):
     return div
 
 
-def nabla(output_, input_, components=None, d=None, method='std'):
+def laplacian(output_, input_, components=None, d=None, method='std'):
     """
-    Perform nabla (laplace) operator. The operator works for vectorial and
+    Compute Laplace operator. The operator works for vectorial and
     scalar functions, with multiple input coordinates.
 
     :param LabelTensor output_: the output tensor onto which computing the
-        nabla.
+        Laplacian.
     :param LabelTensor input_: the input tensor with respect to which computing
-        the nabla.
+        the Laplacian.
     :param list(str) components: the name of the output variables to calculate
-        the nabla for. It should be a subset of the output labels. If None,
+        the Laplacian for. It should be a subset of the output labels. If None,
         all the output variables are considered. Default is None.
-    :param list(str) d: the name of the input variables on which the nabla
+    :param list(str) d: the name of the input variables on which the Laplacian
         is calculated. d should be a subset of the input labels. If None, all
         the input variables are considered. Default is None.
-    :param str method: used method to calculate nabla, defaults to 'std'.
+    :param str method: used method to calculate Laplacian, defaults to 'std'.
     :raises ValueError: for vectorial field derivative with respect to
         all coordinates must be performed.
     :raises NotImplementedError: 'divgrad' not implemented as method.
-    :return: The tensor containing the result of the nabla operator.
+    :return: The tensor containing the result of the Laplacian operator.
     :rtype: LabelTensor
     """
     if d is None:
@@ -217,15 +217,15 @@ def advection(output_, input_, velocity_field, components=None, d=None):
     with multiple input coordinates.
 
     :param LabelTensor output_: the output tensor onto which computing the
-        nabla.
+        advection.
     :param LabelTensor input_: the input tensor with respect to which computing
-        the nabla.
+        the advection.
     :param str velocity_field: the name of the output variables which is used
         as velocity field. It should be a subset of the output labels.
     :param list(str) components: the name of the output variables to calculate
-        the nabla for. It should be a subset of the output labels. If None,
+        the Laplacian for. It should be a subset of the output labels. If None,
         all the output variables are considered. Default is None.
-    :param list(str) d: the name of the input variables on which the nabla
+    :param list(str) d: the name of the input variables on which the advection
         is calculated. d should be a subset of the input labels. If None, all
         the input variables are considered. Default is None.
     :return: the tensor containing the result of the advection operator.

pina/problem/timedep_problem.py

@@ -13,7 +13,7 @@ class TimeDependentProblem(AbstractProblem):
 
     :Example:
         >>> from pina.problem import SpatialProblem, TimeDependentProblem
-        >>> from pina.operators import grad, nabla
+        >>> from pina.operators import grad, laplacian
         >>> from pina import Condition, Span
         >>> import torch
         >>>
@@ -26,8 +26,8 @@ class TimeDependentProblem(AbstractProblem):
         >>>     def wave_equation(input_, output_):
         >>>         u_t = grad(output_, input_, components=['u'], d=['t'])
         >>>         u_tt = grad(u_t, input_, components=['dudt'], d=['t'])
-        >>>         nabla_u = nabla(output_, input_, components=['u'], d=['x'])
-        >>>         return nabla_u - u_tt
+        >>>         delta_u = laplacian(output_, input_, components=['u'], d=['x'])
+        >>>         return delta_u - u_tt
         >>>
         >>>     def nil_dirichlet(input_, output_):
         >>>         value = 0.0