Check the model for mistakes

Your model is checked while you edit it. Mistakes are underlined in the JSON file a moment after you stop typing, without running the model.

Read the problems

1. Look for the underlines in the JSON file. Red is an error, yellow is a warning. Hover one to read the message.

2. Open the Problems panel to see them all: View > Problems, or click the error and warning counts at the left of the status bar.

   

3. Click a problem to go to it.

The Pywr v2 model or Pywr v1 model item of the status bar turns to the warning colour while the model has errors.

Fix a mistake with the light bulb

1. Put the cursor on an underlined mistake.

2. Click the light bulb that appears, or press Ctrl . (Cmd . on macOS).

   

3. Pick a fix.

Mistake	Fixes on offer
A name that does not exist	Replace it with one of the closest names in the model, or create the component with that name. When the name is in an edge, remove the edge.
A name used by two components	Rename this component. The places that use the name are not changed.
A file that cannot be found	Browse for the file. The path is saved relative to the model when the file is in its folder.

What is checked

Pywr v2

Against the Pywr schema. The official description of a Pywr v2 model: the types that exist, the fields each one needs and the values each field accepts.

The names. A name used by two components of the same kind is an error. So is a reference to a node, a parameter, a table or another component that does not exist.

The files. A warning when a file a component reads does not exist.

Mistakes the schema cannot catch. These are warnings, and do not mark the model as having errors:

• a node that is not connected to any other node
• an edge using a slot its node does not have
• a parameter, a table or a timeseries that nothing uses
• a metric set that no output saves
• lists whose lengths must match, such as the values and the control curves of a parameter, or the twelve values of a monthly profile
• a scenario group whose labels or subset do not match its size

Pywr v1

Against a schema. Pywr v1 has no official schema, so the extension uses its own, which describes the types of pywr and the fields of each one.

The names. A name used by two components is an error, and so is a reference to a component that does not exist. A parameter and a recorder cannot share a name.

The files. A warning when a file a component reads does not exist. The files written by the CSV and the tables recorders are not checked.

The rules pywr applies when it loads a model, such as:

• edges must connect nodes that exist
• a storage node needs an initial volume
• keys that are required, or that cannot be used together
• the number of values of control curves and profiles

Custom components. A type that is not part of pywr is looked up in the Python files listed in includes, and in the compiled Cython modules you added. A class found there is accepted as a custom component; a type found nowhere is reported.

Note

A model with no problems can still fail when it runs, for example when a value makes the network impossible to solve. The checks cover the structure of the model, not its behaviour. To check the behaviour, use a QA report.