{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
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            "as": "theta",
            "start": 0,
            "step": 0.1,
            "stop": 6.28
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    },
    "transform": [
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            "as": "y",
            "calculate": "cos(datum.theta)"
        }
    ],
    "vconcat": [
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                    "axis": null,
                    "field": "theta",
                    "type": "quantitative"
                },
                "y": {
                    "axis": null,
                    "field": "y",
                    "type": "quantitative"
                }
            },
            "mark": "line",
            "selection": {
                "brush": {
                    "encodings": [
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                        "y"
                    ],
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                        ],
                        "y": [
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                        ]
                    },
                    "type": "interval"
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        },
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            "encoding": {
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                            "selection": "brush"
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                    "type": "quantitative"
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                            "selection": "brush"
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                    },
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            "mark": "circle"
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    ]
}