returns column contributions for MI

src/Fast_Sparse_Mutual_Information.cpp

@@ -24,3 +24,35 @@ double Fast_Sparse_Mutual_Information(
     }
     return mutual_information;
 }
+
+
+
+
+// [[Rcpp::export]]
+List Fast_Sparse_Mutual_Information_Full(
+        arma::vec rows,
+        arma::vec cols,
+        arma::vec vals,
+        arma::vec colsums,
+        arma::vec rowsums,
+        int num_entries
+){
+
+    arma::vec column_contribution = arma::zeros(colsums.n_elem);
+
+    double mutual_information = 0;
+    // loop over non-zero entries
+    for(int i = 0; i < num_entries; ++i){
+        double temp = std::log((vals[i]/(colsums[cols[i]]*rowsums[rows[i]])));
+        if(!std::isfinite(temp)){
+            temp = 0;
+        }
+        mutual_information += vals[i] * temp;
+        column_contribution[cols[i]] += vals[i] * temp;
+    }
+
+    List to_return(2);
+    to_return[0] = mutual_information;
+    to_return[1] = column_contribution;
+    return to_return;
+}