def get_element_mass(self, element):
"""
Determine the mass of the specified elements in the package.
:returns: Masses. [kg]
"""
result = numpy.zeros(1)
for compound in self.material.compounds:
result += self.get_compound_mass(compound) *\
stoich.element_mass_fractions(compound, [element])
return result[0]
def get_element_masses(self, elements=None):
"""
Determine the masses of elements in the package.
:returns: Array of element masses. [kg]
"""
if elements is None:
elements = self.material.elements
result = numpy.zeros(len(elements))
for compound in self.material.compounds:
result += self.get_compound_mass(compound) *\
stoich.element_mass_fractions(compound, elements)
return result
