Add convergence tasks for space and time only

docs/developers_guide/ocean/api.md

@@ -313,18 +313,21 @@
 .. autosummary::
    :toctree: generated/
 
-   ConvergenceForward
-   ConvergenceForward.compute_cell_count
-   ConvergenceForward.dynamic_model_config
-
-   ConvergenceAnalysis
-   ConvergenceAnalysis.compute_error
-   ConvergenceAnalysis.convergence_parameters
-   ConvergenceAnalysis.exact_solution
-   ConvergenceAnalysis.get_output_field
-   ConvergenceAnalysis.plot_convergence
-   ConvergenceAnalysis.run
-   ConvergenceAnalysis.setup
+   get_resolution_for_tasks
+   get_timestep_for_tasks
+
+   forward.ConvergenceForward
+   forward.ConvergenceForward.compute_cell_count
+   forward.ConvergenceForward.dynamic_model_config
+
+   analysis.ConvergenceAnalysis
+   analysis.ConvergenceAnalysis.compute_error
+   analysis.ConvergenceAnalysis.convergence_parameters
+   analysis.ConvergenceAnalysis.exact_solution
+   analysis.ConvergenceAnalysis.get_output_field
+   analysis.ConvergenceAnalysis.plot_convergence
+   analysis.ConvergenceAnalysis.run
+   analysis.ConvergenceAnalysis.setup
 ```
 ### Spherical Convergence Tests
 

docs/developers_guide/ocean/framework.md

@@ -219,16 +219,35 @@ tests on {ref}`dev-ocean-spherical-meshes` and planar meshes.
 The ocean framework includes shared config options and base classes for
 forward and analysis steps that are expected to be useful across these tests.
 
+The key config options that control the convergence test are `base_resolution`
+and `refinement_factors`. The `base_resolution` is multipled by the
+`refinement_factors` to determine which resolutions to test when the
+convergence is being tested in space (or space and time together). The
+`base_resolution` is applied to all steps when convergence in time is tested.
+`base_resolution` times `dt_per_km` determines the base timestep in that case
+and is then multiplied by the `refinement_factors` to determine which time steps
+to test. When spherical meshes are being tested, the values in the 
+`convergence` section are overridden by their values in the
+`spherical_convergence` section with a prefix indicating the mesh type.
+
 The shared config options are:
 ```cfg
 # config options for spherical convergence tests
 [spherical_convergence]
 
+# The base resolution for the icosahedral mesh to which the refinement
+# factors are applied
+icos_base_resolution = 60.
+
 # a list of icosahedral mesh resolutions (km) to test
-icos_resolutions = 60, 120, 240, 480
+icos_refinement_factors = 8., 4., 2., 1.
+
+# The base resolution for the quasi-uniform mesh to which the refinement
+# factors are applied
+qu_base_resolution = 120.
 
 # a list of quasi-uniform mesh resolutions (km) to test
-qu_resolutions = 60, 90, 120, 150, 180, 210, 240
+qu_refinement_factors = 0.5, 0.75, 1., 1.25, 1.5, 1.75, 2.
 
 [convergence]
 
@@ -241,6 +260,15 @@ convergence_thresh = 1.0
 # Type of error to compute
 error_type = l2
 
+# the base mesh resolution (km) to which refinement_factors
+# are applied if refinement is 'space' or 'both' on a planar mesh
+# base resolutions for spherical meshes are given in section spherical_convergence
+base_resolution = 120
+
+# refinement factors for a planar mesh applied to either space or time
+# refinement factors for a spherical mesh given in section spherical_convergence
+refinement_factors = 4., 2., 1., 0.5
+
 # config options for convergence forward steps
 [convergence_forward]
 
@@ -325,7 +353,8 @@ class Forward(SphericalConvergenceForward):
     bell test case
     """
 
-    def __init__(self, component, name, subdir, resolution, mesh, init):
+    def __init__(self, component, name, subdir, mesh, init,
+                 refinement_factor, refinement='both'):
         """
         Create a new step
 
@@ -348,6 +377,9 @@ class Forward(SphericalConvergenceForward):
 
         init : polaris.Step
             The init step
+
+        refinement_factor : float
+            The factor by which to scale space, time or both
         """
         package = 'polaris.ocean.tasks.cosine_bell'
         validate_vars = ['normalVelocity', 'tracer1']
@@ -356,7 +388,10 @@ class Forward(SphericalConvergenceForward):
                          init=init, package=package,
                          yaml_filename='forward.yaml',
                          output_filename='output.nc',
-                         validate_vars=validate_vars)
+                         validate_vars=validate_vars,
+                         graph_target=f'{init.path}/graph.info',
+                         refinement_factor=refinement_factor,
+                         refinement=refinement)
 ```
 Each convergence test must define a YAML file with model config options, called
 `forward.yaml` by default.  The `package` parameter is the location of this
@@ -419,7 +454,7 @@ class Analysis(ConvergenceAnalysis):
     """
     A step for analyzing the output from the cosine bell test case
     """
-    def __init__(self, component, resolutions, subdir, dependencies):
+    def __init__(self, component, subdir, dependencies, refinement='both'):
         """
         Create the step
 
@@ -436,14 +471,18 @@ class Analysis(ConvergenceAnalysis):
 
         dependencies : dict of dict of polaris.Steps
             The dependencies of this step
+
+        refinement : str, optional
+            Whether to refine in space, time or both space and time
         """
         convergence_vars = [{'name': 'tracer1',
                              'title': 'tracer1',
                              'zidx': 0}]
         super().__init__(component=component, subdir=subdir,
                          resolutions=resolutions,
                          dependencies=dependencies,
-                         convergence_vars=convergence_vars)
+                         convergence_vars=convergence_vars,
+                         refinement=refinement)
 ```
 
 Many tasks will also need to override the

docs/users_guide/ocean/tasks/cosine_bell.md

@@ -33,34 +33,56 @@ These tasks support only MPAS-Ocean.
 (ocean-cosine-bell-mesh)=
 ## mesh
 
-Two global mesh variants are tested, quasi-uniform (QU) and icosohydral. Thus,
-there are 4 variants of the task:
+Two global mesh variants are tested, quasi-uniform (QU) and icosohydral. There
+are also variants to test convergence in space, time, or both space and time.
+In addition, the tests can be set up with or without the viz step. Thus, there
+are 12 variants of the task:
 ```
-ocean/spherical/icos/cosine_bell
-ocean/spherical/icos/cosine_bell/with_viz
-ocean/spherical/qu/cosine_bell
-ocean/spherical/qu/cosine_bell/with_viz
+ocean/spherical/icos/cosine_bell/convergence_both/
+ocean/spherical/icos/cosine_bell/convergence_both/with_viz
+ocean/spherical/qu/cosine_bell/convergence_both/
+ocean/spherical/qu/cosine_bell/convergence_both/with_viz
+ocean/spherical/icos/cosine_bell/convergence_space/
+ocean/spherical/icos/cosine_bell/convergence_space/with_viz
+ocean/spherical/qu/cosine_bell/convergence_space/
+ocean/spherical/qu/cosine_bell/convergence_space/with_viz
+ocean/spherical/icos/cosine_bell/convergence_time/
+ocean/spherical/icos/cosine_bell/convergence_time/with_viz
+ocean/spherical/qu/cosine_bell/convergence_time/
+ocean/spherical/qu/cosine_bell/convergence_time/with_viz
 ```
 The default resolutions used in the task depends on the mesh type.
 
-For the `icos` mesh type, the defaults are:
+For the `icos` mesh type, the defaults are 60, 120, 240, 480 km, as determined
+by the following config options. See {ref}`dev-ocean-convergence` for more
+details.
 
 ```cfg
 # config options for spherical convergence tests
 [spherical_convergence]
 
+# The base resolution for the icosahedral mesh to which the refinement
+# factors are applied
+icos_base_resolution = 60.
+
+# a list of icosahedral mesh resolutions (km) to test
+icos_refinement_factors = 8., 4., 2., 1.
 # a list of icosahedral mesh resolutions (km) to test
-icos_resolutions = 60, 120, 240, 480
 ```
 
-for the `qu` mesh type, they are:
+For the `qu` mesh type, they are 60, 90, 120, 150, 180, 210, 240 km as
+determined by the following config options:
 
 ```cfg
 # config options for spherical convergence tests
 [spherical_convergence]
 
+# The base resolution for the quasi-uniform mesh to which the refinement
+# factors are applied
+qu_base_resolution = 120.
+
 # a list of quasi-uniform mesh resolutions (km) to test
-qu_resolutions = 60, 90, 120, 150, 180, 210, 240
+qu_refinement_factors = 0.5, 0.75, 1., 1.25, 1.5, 1.75, 2.
 ```
 
 To alter the resolutions used in this task, you will need to create your own

docs/users_guide/ocean/tasks/geostrophic.md

@@ -4,20 +4,25 @@
 
 ## description
 
-The `geostrophic` and `geostrophic/with_viz` tasks implement the "Global Steady
+The `geostrophic` tasks implement the "Global Steady
 State Nonlinear Zonal Geostrophic Flow" test case described in
 [Williamson et al. 1992](<https://doi.org/10.1016/S0021-9991(05)80016-6>)
 
-The task is a convergence test with time step varying proportionately to grid
-size. The result of the `analysis` step of the task are plots like the
-following showing convergence of water-column thickness and normal velocity as
-functions of the mesh resolution:
+The task `geostrophic/convergence_both` is a space-and-time convergence test
+with time step varying proportionately to grid size. Convergence tests in
+either space or time are also available as `convergence_space` or 
+`convergence_time`. The result of the `analysis` step of the task are plots
+like the following showing convergence of water-column thickness and normal
+velocity as functions of the mesh resolution:
 
 ```{image} images/geostrophic_convergence.png
 :align: center
 :width: 500 px
 ```
 
+Visualizations of the fields themselves can be added in viz steps by appending
+`with_viz` to the task name at setup.
+
 ## suppported models
 
 These tasks support only MPAS-Ocean.

docs/users_guide/ocean/tasks/inertial_gravity_wave.md

@@ -11,6 +11,14 @@ The implementation is from
 
 ## description
 
+There are 3 versions of the convergence test case, `convergence_space`,
+`convergence_time`, and `convergence_both` corresponding to space, time, and
+space and time convergence tests. Tests involving spatial convergence run the
+inertial gravity wave simulation for 4 different resolutions: 200, 100, 50,
+and 25 km. Tests involving temporal convergence use the parameter `dt_per_km`
+at the `base_resolution` multiplied by `refinement_factors` (see
+{ref}`dev-ocean-convergence` for more details on how to change resolutions or
+time steps tested).
 The `inertial_gravity_wave` task runs the inertial gravity wave simulation for 4
 different resolutions: 200, 100, 50, and 25 km.
 

docs/users_guide/ocean/tasks/manufactured_solution.md

@@ -22,8 +22,14 @@ These tasks support both MPAS-Ocean and Omega.
 
 ### description
 
-The `convergence` test case runs the manufactured solution simulation for 4
-different resolutions: 200, 100, 50, and 25 km.
+There are 3 versions of the convergence test case, `convergence_space`,
+`convergence_time`, and `convergence_both` corresponding to space, time, and
+space and time convergence tests. Tests involving spatial convergence run the
+manufactured solution simulation for 4 different resolutions: 200, 100, 50,
+and 25 km. Tests involving temporal convergence use the parameter `dt_per_km`
+at the `base_resolution` multiplied by `refinement_factors` (see
+{ref}`dev-ocean-convergence` for more details on how to change resolutions or
+time steps tested).
 
 The forward step for each resolution runs the simulation for 10 hours. The
 model is configured without vertical advection and mixing. No tracers are enabled

polaris/ocean/convergence/__init__.py

@@ -1,2 +1,106 @@
-from polaris.ocean.convergence.analysis import ConvergenceAnalysis
-from polaris.ocean.convergence.forward import ConvergenceForward
+import numpy as np
+
+
+def get_resolution_for_task(config, refinement_factor,
+                            refinement='both'):
+    """
+    Get the resolution for a step in a convergence task
+
+    Parameters
+    ----------
+    config : polaris.Config
+        The config options for this task
+
+    refinement_factor : float
+        The factor by which either resolution or time is refined for this step
+
+    refinement : str, optional
+        Whether to refine in space, time or both
+
+    Returns
+    -------
+    resolution : float
+        The resolution corresponding to the refinement_factor and convergence
+        test type
+    """
+    if refinement == 'both':
+        option = 'refinement_factors_space'
+    else:
+        option = f'refinement_factors_{refinement}'
+    base_resolution = config.getfloat('convergence', 'base_resolution')
+    refinement_factors = config.getlist('convergence', option, dtype=float)
+
+    if refinement_factor not in refinement_factors:
+        raise ValueError(
+            'refinement_factor not found in config option refinement_factors')
+
+    if refinement == 'time':
+        resolution = base_resolution
+    else:
+        resolution = refinement_factor * base_resolution
+
+    return resolution
+
+
+def get_timestep_for_task(config, refinement_factor,
+                          refinement='both'):
+    """
+    Get the time step for a forward step in a convergence task
+
+    Parameters
+    ----------
+    config : polaris.Config
+        The config options for this task
+
+    refinement_factor : float
+        The factor by which either resolution or time is refined for this step
+
+    refinement : str, optional
+        Whether to refine in space, time or both
+
+    Returns
+    -------
+    resolution : float
+        The resolution corresponding to the refinement_factor and convergence
+        test type
+    """
+
+    if refinement == 'both':
+        option = 'refinement_factors_space'
+    else:
+        option = f'refinement_factors_{refinement}'
+    base_resolution = config.getfloat('convergence', 'base_resolution')
+    refinement_factors = config.getlist('convergence', option, dtype=float)
+
+    if refinement_factor not in refinement_factors:
+        raise ValueError(
+            'refinement_factor not found in config option refinement_factors')
+
+    resolution = get_resolution_for_task(
+        config, refinement_factor, refinement=refinement)
+
+    section = config['convergence_forward']
+    time_integrator = section.get('time_integrator')
+    # dt is proportional to resolution: default 30 seconds per km
+    if time_integrator == 'RK4':
+        dt_per_km = section.getfloat('rk4_dt_per_km')
+        btr_timestep = 0.
+    else:
+        dt_per_km = section.getfloat('split_dt_per_km')
+        btr_dt_per_km = section.getfloat('btr_dt_per_km')
+        for idx, refinement_factor in enumerate(refinement_factors):
+            if refinement == 'time':
+                btr_timestep = btr_dt_per_km * base_resolution * \
+                    refinement_factor
+            elif refinement == 'space':
+                btr_timestep = btr_dt_per_km * base_resolution
+            else:
+                btr_timestep = btr_dt_per_km * resolution
+    if refinement == 'time':
+        timestep = dt_per_km * refinement_factor * resolution
+    elif refinement == 'space':
+        timestep = dt_per_km * base_resolution
+    else:
+        timestep = dt_per_km * resolution
+
+    return timestep, btr_timestep