[Python/1D] Make current solution residuals accessible

interfaces/cython/cantera/_cantera.pxd

@@ -725,6 +725,7 @@ cdef extern from "cantera/oneD/Sim1D.h":
         int domainIndex(string) except +translate_exception
         double value(size_t, size_t, size_t) except +translate_exception
         double workValue(size_t, size_t, size_t) except +translate_exception
+        void eval(double ) except +translate_exception
         size_t size()
         void solveAdjoint(const double*, double*) except +translate_exception
         void getResidual(double, double*) except +translate_exception

interfaces/cython/cantera/onedim.pyx

@@ -649,9 +649,20 @@ cdef class Sim1D:
         dom, comp = self._get_indices(domain, component)
         self.sim.setValue(dom, comp, point, value)
 
+    def eval(self, rdt=0.0):
+        """
+        Evaluate the governing equations using the current solution estimate,
+        storing the residual in the array which is accessible with the
+        `work_value` function.
+
+        :param rdt:
+           Reciprocal of the time-step
+        """
+        self.sim.eval(rdt)
+
     def work_value(self, domain, component, point):
         """
-        Internal work array value at one point. After calling eval, this array
+        Internal work array value at one point. After calling `eval`, this array
         contains the values of the residual function.
 
         :param domain: