adds relative relatedness

Adds the relative_relatedness function, based on the `relative-relatedness` branch.

economic_complexity/__init__.py

@@ -13,6 +13,7 @@
     proximity,
     relatedness,
     similarity,
+    relative_relatedness
 )
 from .rca import rca
 from .subnational import complexity_subnational
@@ -33,4 +34,5 @@
     "pgi",
     "peii",
     "complexity_subnational",
+    "relative_relatedness"
 )

economic_complexity/product_space.py

@@ -378,3 +378,48 @@ def peii(
     peii = _pmi(tbl=tbl, rcas=rcas, measure=emissions, cutoff=cutoff)
     peii.rename(columns={peii.columns[0]: name}, inplace=True)
     return peii
+
+
+def relative_relatedness(
+    rcas: pd.DataFrame,
+    *,
+    cutoff: float = 1,
+    proximities: Optional[pd.DataFrame] = None,
+) -> pd.DataFrame:
+    """Calculates the Relative Relatedness, given a matrix of RCAs for the economic
+    activities of a location, and a matrix of Proximities.
+
+    ### Args:
+    * rcas (pd.DataFrame) -- Matrix of RCAs for a certain location.
+
+    ### Keyword Args:
+    * cutoff (float, optional) -- Set the cutoff threshold value.
+        Internally, RCA values under it will be set to zero, one otherwise.
+        Default value: `1`.
+    * proximities (pd.DataFrame, optional) -- Matrix with the proximity between the elements.
+        If not provided, will be calculated using the "max" procedure, and
+        the same cutoff value for this call.
+
+    ### Returns:
+    (pd.DataFrame) -- A matrix with the probability that a location generates
+        comparative advantages in a economic activity.
+    """
+
+    opp = rcas.copy()
+
+    if cutoff == 0:
+        opp = 1
+    else: 
+        opp[opp >= cutoff] = pd.NA
+        opp[opp < cutoff] = 1
+
+    if proximities is None:
+        wcp = relatedness(rcas, cutoff)
+    else:
+        wcp = relatedness(rcas, cutoff, proximities)
+
+    wcp_opp = opp*wcp
+    wcp_mean =  wcp_opp.mean(axis=1)
+    wcp_std =  wcp_opp.std(axis=1)
+
+    return wcp.transform(lambda x: (x-wcp_mean)/wcp_std)

tests/test_product_space.py

@@ -36,3 +36,7 @@ def test_pgi(df_global_exports, df_rca):
 
 def test_peii():
     pass
+
+def test_relative_relatedness(df_rca):
+    relt = ec.relative_relatedness(df_rca)
+    pass