Vega Chart widgets in Decision Optimization experiments
The Vega Chart widget in the Visualization view uses Vega-Lite specifications to create different types of chart (bar charts, point charts, and so on) .
If you leave spec
empty, a simple bar chart is automatically generated with the
first string column in x-axis and the first number in y-axis.
Vega-Lite enables data filtering and transformation. For example, strings can be transformed into dates.
To learn more about Vega-Lite, see Vega-Lite - A High-Level Visualization Grammar.
The following advanced example shows the specification for a grouped bar chart based on a population data table. This example shows how to filter data and how to compute a virtual column:
{
"name": "Population Grouped Bar Chart",
"type": "Chart",
"props": {
"data": "population",
"spec": {
"transform": [
{
"filter": "datum.year == 2000"
},
{
"calculate": "datum.sex == 2 ? 'Female' : 'Male'",
"as": "gender"
}
],
"mark": "bar",
"encoding": {
"column": {
"field": "age",
"type": "ordinal"
},
"y": {
"aggregate": "sum",
"field": "people",
"type": "quantitative",
"axis": {
"title": "population",
"grid": false
}
},
"x": {
"field": "gender",
"type": "nominal",
"scale": {
"rangeStep": 12
},
"axis": {
"title": ""
}
},
"color": {
"field": "gender",
"type": "nominal",
"scale": {
"range": [
"#EA98D2",
"#659CCA"
]
}
}
},
"config": {
"facet": {
"cell": {
"strokeWidth": 0
}
},
"axis": {
"domainWidth": 1
}
}
}
}
}