SankeyMATIC Manual

Flow Cross-Check

What and Why

For many kinds of Sankey diagrams, it is important to make sure that all of the inputs are mapped to a visible output.

Examples include:

  • Budgets and other money flows, where each dollar (or each yen, etc.) must be accounted for.
  • Energy diagrams, where 100% of inputs must map to outputs. (Typically, any unused energy is explicitly shown flowing to a 'Waste' or 'Rejected' node rather than being left out of the diagram).

When you begin any new diagram, SankeyMATIC automatically compares total inputs and outputs for any node which has both.

If they do not match, you will see a warning message. Warnings look like this:

Example warnings. The Flow Cross-Checker found some Imbalances. Node 'Budget', Amount IN (2025) != OUT (1575); delta = +450. Diagram Total IN (2025) != Total OUT (1575); delta = +450.

In the messages, SankeyMATIC will tell you:

  • the specific node names which have non-matching inputs and outputs
  • the amount in, the amount out, and the difference (or delta, Δ) between them.

Note: The diagram itself will not display any differently when there is an imbalance.

The messages are purely there to be useful to you as you create your diagram.

Turning Off Flow Cross-Check

Some diagrams do not require equal inputs and outputs.

One popular example is a 'funnel'-style diagram, which shows a large number of initial values narrowing down to smaller numbers as you proceed through the diagram.

To silence the warnings about imbalances, you can turn off the Flow Cross-Check feature in the “Advanced” control panel section:

Inside the control panel named 'Advanced', the checkbox 'Flow Cross-Check' is shown, checked.

When this box is un-checked, SankeyMATIC will no longer display any warnings regarding imbalances in the diagram.