Time-over-Time Comparison

Time-over-time comparison allows you to add a measure representing data from the past and compare it to another measure in a visualization. The visualization must contain at least one measure that the measure with the data from the past can reference.

The measure with the data from the past is called derived measure. The referenced measure is called master measure.

You can compare data to:

• The same period previous year
• The previous period

We do not recommend that you create a derived measure from an arithmetic measure that refers to another derived measure. The resulting derived measure may be hard to interpret.

Comparing to the same period (SP) previous year

Time shift: -1 year

Period: 1 year

To add a SP derived measure to a visualization, use the following newPopMeasure factory function:

newPopMeasure(masterMeasureOrLocalId, overPeriodAttributeId, modifications)

where:

• masterMeasureOrLocalId is the measure with data to compare; specify either the measure’s localIdentifier or the measure itself.
• overPeriodAttributeId is the identifier of the date dimension year attribute to use for the shift.
• modifications is a function that receives an object with functions to customize format() and alias().

Example

import { PivotTable } from "@gooddata/sdk-ui-pivot";
import { newMeasure, newPopMeasure } from "@gooddata/sdk-model";

const masterMeasure = newMeasure("measureIdentifier", m => m.alias("Master Measure"));
const popMeasure = newPopMeasure(masterMeasure, "attributeYearIdentifier", m => m.alias("Same Period Previous Year"));

const measures = [
    masterMeasure,
    popMeasure
];

<PivotTable
    measures={measures}
/>

Comparing to the previous period (PP)

Time shift: a specified number of periods

Period: defined by global date filters referenced by the date dataset URI or identifier in the derived measure definition

• For an absolute date filter, the period is N days.
• For a relative date filter, the period can be N days, weeks, months, quarters, or years depending on the selected granularity.

If no global date filter is defined, the derived measure returns the same data as the master measure.

To add a PP derived measure to a visualization, use the following newPreviousPeriodMeasure factory function:

newPreviousPeriodMeasure(masterMeasureOrLocalId, dateDataSetsShift, modifications);

where:

• masterMeasureOrLocalId is the measure with data to compare; specify either the measure’s localIdentifier or the measure itself.
• dateDataSetsShift is the definition of the period shift to apply; it is an object with the dataSet prop for the date dataset identifier and the periodsAgo prop to specify the period shift.
• modifications is a fucntion that receives an object with functions to customize format() and alias().

Example

import { newMeasure, newPreviousPeriodMeasure, newRelativeDateFilter } from "@gooddata/sdk-model";
import { PivotTable } from "@gooddata/sdk-ui-pivot";

const filters = [
    newRelativeDateFilter("dateDatasetIdentifier", "GDC.time.date", -7, -1)
];

// master - last 7 days measure
const masterMeasure = newMeasure("measureIdentifier", m => m.alias("Master Measure"));
// derived - previous 7 days measure
const previousPeriod = newPreviousPeriodMeasure(
                            masterMeasure,
                            { dataSet: "dateDatasetIdentifier", periodsAgo: 1},
                            m => m.alias("Previous Period Measure")
                        );

const measures = [
    masterMeasure,
    previousPeriod
];

<PivotTable
    measures={measures}
    filters={filters}
/>

Comparison to the PP and absolute date filters

Be careful when combining comparison to the PP with an absolute date filter. For example, when filtering from March 1 to March 31, the previous period is the previous 31 days and not the previous month. For comparing over a period other than a day, use a relative date filter with the required granularity (month, quarter).

More examples

See the live examples.