Intervention flows

The intervention flows are the flows that cross the boundary with the environment of the calculated system (this is why the short name is EnviFlow).

To retrieve the intervention matrix, we use the enviIndex method. It will return an iterator of EnviFlows: EnviIndex, which maps symmetrically the rows (intervention flows) and columns (technosphere flows).

class EnviFlow:
    def flow(): # () -> FlowDescriptor
    def location(): # () -> LocationDescriptor
    def isInput(): # () -> bool
    def wrapped(): # () -> Descriptor

NOTE: More information about LocationDescriptor, FlowDescriptor and Descriptor can be found in the The advanced data model chapter.

You can create an EnviFlow object by calling the EnviFlow.inputOf and EnviFlow.outputOf methods.

envi_flow = EnviFlow.inputOf(flow_descriptor)  # (FlowDescriptor) -> EnviFlow
envi_flow = EnviFlow.outputOf(flow_descriptor)  # (FlowDescriptor) -> EnviFlow

envi_index = result.enviIndex()
for envi_flow in envi_index:
    print("Flow: %s\nIs input? %s\n" % (envi_flow.flow().name, envi_flow.isInput()))

Inventory results

To get the inventory results, the quantitative list of all the material and energy flows into and out of the system boundary, we use the getTotalFlows method. It will return a list of EnviFlowValue, which is a record of an EnviFlow and the amount of the flow.

class EnviFlowValue:
    def enviFlow(): # () -> EnviFlow
    def value(): # () -> float

envi_flow_values = result.getTotalFlows()
for envi_flow_value in envi_flow_values:
    in_or_out = "input" if envi_flow_value.isInput() else "output"
    print(
        "The total amount of the %s %s is %s."
        % (in_or_out, envi_flow_value.flow().name, envi_flow_value.value())
    )

Direct contributions

To get the direct contributions of a each process to the inventory result of a flow, we use the getDirectFlowValuesOf method. It will return a list of TechFlowValue.

envi_flow = EnviFlow.inputOf(flow_descriptor)
contributions = result.getDirectFlowValuesOf(envi_flow)
for contribution in contributions:
    print(
        "The contribution of %s is %s."
        % (contribution.techFlow().flow().name, contribution.value())
    )

Total values

The total value of a flow for a given process is the total inventory result at this point of the supply chain. It includes the direct, upstream, and downstream (related to waste treatment) contributions.

envi_flow = EnviFlow.inputOf(flow_descriptor)
total_values = result.getTotalFlowValuesOf(envi_flow)
for total_value in total_values:
    print(
        "The total value of %s is %s."
        % (total_value.techFlow().flow().name, total_value.value())
    )

Direct process results

The direct process results are the direct intervention flows of a process to fulfill the demand of the product system.

tech_flow = TechFlow.of(provider, flow)
envi_flow_values = result.getDirectFlowsOf(tech_flow)
for envi_flow_value in envi_flow_values:
    print(
        "The direct amount of %s is %s."
        % (envi_flow_value.enviFlow().flow().name, envi_flow_value.value())
    )

And more...

For more specific methods, please refer to the LcaResult class.