Recomputing the diagonal when generating parameters to counter the precision loss and increase `f64::EPSILON` calculating its square root instead of multiplying it with the node's `domain_size`

reCTBN/src/params.rs

@@ -267,13 +267,11 @@ impl ParamsTrait for DiscreteStatesContinousTimeParams {
             )));
         }
 
-        let domain_size = domain_size as f64;
-
         // Check if each row sum up to 0
         if cim
             .sum_axis(Axis(2))
             .iter()
-            .any(|x| f64::abs(x.clone()) > f64::EPSILON * domain_size)
+            .any(|x| f64::abs(x.clone()) > f64::EPSILON.sqrt())
         {
             return Err(ParamsError::InvalidCIM(String::from(
                 "The sum of each row must be 0",

reCTBN/src/tools.rs

@@ -203,7 +203,10 @@ impl RandomParametersGenerator for UniformParametersGenerator {
                     self.rng.gen_range(self.interval.clone())
                 });
                 x.mul_assign(&diag.clone().insert_axis(Axis(1)));
-                x.diag_mut().assign(&-diag)
+                // Recomputing the diagonal in order to reduce the issues caused by the loss of
+                // precision when validating the parameters.
+                let diag_sum = -x.sum_axis(Axis(1));
+                x.diag_mut().assign(&diag_sum)
             });
             match &mut net.get_node_mut(node) {
                 params::Params::DiscreteStatesContinousTime(param) => {