ValueError: group_by contains variable(s) ['group'] that could not be found in the entity index.

[adelavega]

With pybids 0.15.1, we get the following error:

ValueError: group_by contains variable(s) ['group'] that could not be found in the entity index.

for model:

{
  "Name": "Test medium",
  "Input": {
    "Run": [
      1,
      2
    ],
    "Task": "movie",
    "Subject": [
      "sid000005",
      "sid000007",
      "sid000009"
    ]
  },
  "Description": "",
  "BIDSModelVersion": 1,
  "Nodes": [
    {
      "Level": "run",
      "Model": {
        "X": [
          "speech",
          1
        ]
      },
      "Contrasts": [
        {
          "Name": "speech",
          "Type": "t",
          "Weights": [
            1
          ],
          "ConditionList": [
            "speech"
          ],
          "Test": "t"
        }
      ],
      "Name": "run",
      "GroupBy": [
        "run",
        "subject"
      ],
      "Transformations": {
        "Transformer": "pybids-transforms-v1",
        "Instructions": [
          {
            "Name": "Convolve",
            "Input": [
              "speech"
            ]
          }
        ]
      }
    },
    {
      "Level": "subject",
      "DummyContrasts": {
        "Test": "t"
      },
      "Name": "subject",
      "GroupBy": [
        "subject",
        "contrast"
      ],
      "Model": {
        "X": [
          1
        ],
        "Type": "Meta"
      }
    },
    {
      "Level": "dataset",
      "DummyContrasts": {
        "Test": "t"
      },
      "Name": "dataset",
      "GroupBy": [
        "contrast",
        "group"
      ],
      "Model": {
        "X": [
          1
        ]
      }
    }
  ]
}

Looks like the final groupby should be dataset

[effigies]

Just drop group unless there are groups. I've also considered whether we should introduce an implicit "all" group so that you can use the same model whether or not a group variable is present in the dataset.

[adelavega]

Ah, I think I was confused as to whether this was even valid or should be "dataset". Raised an issue in modelzoo but that one did have groups I believe, so can disregard that.