functions to load firecrown likelihoods from path or module

augur/utils/firecrown_utils.py

@@ -0,0 +1,102 @@
+"""
+This is similar to what was built in the Blinding likelihood
+"""
+import importlib 
+import os
+import types
+
+from firecrown.likelihood.likelihood import NamedParameters
+from firecrown.likelihood.likelihood import load_likelihood
+from firecrown.likelihood.likelihood import load_likelihood_from_module_type
+
+def load_module_from_path(path):
+    """
+    Load a module from a given path.
+
+    Parameters
+    ----------
+    path : str
+        Path to the module to load.
+
+    Returns
+    -------
+    module
+        Module loaded from the given path.
+    """
+    spec = importlib.util.spec_from_file_location("module.name", path)
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+def _test_likelihood(likelihood, like_type):
+    """
+    Tests if the likelihood has the required methods.
+
+    Parameters
+    ----------
+    likelihood : str or module
+        path to the likelihood or a module containing the likelihood
+        must contain both `build_likelihood` and `compute_theory_vector` methods
+    like_type : str
+        Type of likelihood. Can be either 'str' or 'module'.
+    """
+    if like_type == "str":
+        likelihood = load_module_from_path(likelihood)
+    else:
+        likelihood = likelihood
+
+    # checks if the module has the attribute `build_likelihood`
+    if not hasattr(likelihood, "build_likelihood"):
+        raise AttributeError("The likelihood module must have a `build_likelihood` method.")
+
+def _load_likelihood(likelihood, sacc_data):
+    """
+    This is a healper frunction from DESC/Blinding to load the firecrown likelihoods
+
+    Parameters
+    ----------
+    likelihood : str or module
+        path to the likelihood or a module containing the likelihood
+        must contain both `build_likelihood` and `compute_theory_vector` methods
+    sacc_data : str
+        Path to the sacc data file.
+
+    Returns
+    -------
+    likelihood
+        The likelihood object
+    tools
+        The Modelling Tools object
+    """
+    build_parameters = NamedParameters({'sacc_data': sacc_data})
+
+    if type(likelihood) == str:
+        if not os.path.isfile(likelihood):
+            raise FileNotFoundError(f"File {likelihood} not found.")
+
+        # test the likelihood
+        _test_likelihood(likelihood, "str")
+
+        #load the likelihood
+        likelihood, tools = load_likelihood(likelihood, build_parameters)
+
+        # check if the likehood has a `compute_theory_vector` method
+        if not hasattr(likelihood, "compute_theory_vector"):
+            raise AttributeError("The likelihood must have a `compute_theory_vector` method.")
+        return likelihood, tools
+    elif isinstance(likelihood, types.ModuleType):
+        # test the likelihood
+        _test_likelihood(likelihood, "module")
+
+        # tries to load the likelihood from module
+        likelihood, tools = load_likelihood_from_module_type(likelihood, build_parameters)
+        if not hasattr(likelihood, "compute_theory_vector"):
+            raise AttributeError("The likelihood must have a `compute_theory_vector` method.")
+        return likelihood, tools
+    else:
+        raise TypeError("Likelihood must be either a string or a module.")
+
+
+def load_firecrown_likelihood(likelihood, cosmo, sacc_data, syst_dict=None):
+    # if likelihood is a string, load it from firecrown
+    pass