Scatter Chart Widget

The Scatter Chart widget is useful for discovering the connection between different metrics in your data: it can be used to visualize any results containing two or more sets of correlated numerical values, in the form of scatter plot points. The first set of numerical values in the result will function as points on the X-axis, whereas all following sets will be plotted as series in the chart.

See in Figure 176, “Scatter Chart” an example of how this widget may look like.

Scatter Chart

Figure 176. Scatter Chart


Input Format

You can use the Scatter Chart with a single series to have a service producing logs like the ones below:

ini
2022-03-14T10:59:02.387+0000 INFO c.h.u.TimerExecutor$ 3 cputime=266935 wallclock=269564 alloc=4712
2022-03-14T10:59:02.389+0000 INFO c.h.u.TimerExecutor$ 1 cputime=17521 wallclock=19430 alloc=40
2022-03-14T10:59:02.419+0000 INFO c.h.u.TimerExecutor$ 3 cputime=95658 wallclock=98754 alloc=64

Assuming we would like to make a chart showing the correlation between cputime, wallclock and memory allocation alloc, we will use the table() function:

logscale
table([cputime, wallclock, alloc])

This query will produce a Scatter Chart with cputime as the X-axis and wallclock and alloc as two series of plotted numerical values (as in Figure 176, “Scatter Chart”). Any additional inputs to the table() function field list would add more series to the chart.

The Scatter Chart is also meant to be used in conjunction with other functions such as select(), groupBy(), timeChart(), bucket(), and top().

Wide or Long Input Format

The Scatter Chart offers the Input Data Format property, whose Auto mode looks at the query result and automatically chooses the best interpretation of the data between long or wide data format.

  • Long format data must have one group field for the series names and two additional fields for x and y values respectively.

  • Wide format must have at least two fields (neither needs to be a group field), the first one is used for x values and any subsequent fields contain y values. There is a limit of 49 series when the wide format is chosen (50 in total, but the x axis takes the first slot).

Notice that a group field is the field used as the first argument to either groupBy(), bucket() or timeChart() functions.

See an example of Auto mode selecting the long data format, where we will use a nested groupBy() function:

logscale
groupBy(#vhost, function=[groupBy(alloc)])
Scatter Chart Selecting Long Format

Figure 177. Scatter Chart Selecting Long Format


Widget Properties

Click the Widget icon on the right-hand side of the Event List to open the side panel and configure the following properties.

General properties:

  • Title

    The title of the widget as displayed in the dashboard.

  • Description

    The description of the chart. This is free form text supporting markdown syntax.

    This same description will appear in the dashboard as a tool-tip by hovering over the question mark on top of the widget.

Default time properties. The default widget time only works when Shared time is toggled off by default. Save the dashboard to set the current time selection as the default.

  • Time

  • Start

  • End

Click the Styling brush icon on the right-hand side of the Event List to open the side panel and configure the following properties:

Styling properties:

  • Legend

    • Labels Valid options for displaying labels are:

      • Truncate shortens the length of the series for a better visualization within the chart. It is used in case of long labels that would exceed the maximum space allowed in the chart. It is the default option. Hover the mouse over a label, then press and hold ALT to momentarily see the full series.

      • Show full shows the full name of the series, that is, the entire value is displayed in the label or tooltip. In case of very long labels, it might affect their visibility within the chart. Hover the mouse over a label, then press and hold ALT to momentarily see the truncated series.

    • Show legend checkbox to show the legend in the chart.

    • Position allows choosing where in the chart the legend should appear. Valid options are:

      • Right

      • Bottom

    • Show title checkbox allows to show or hide the legend's title.

    • Title sets a title for the legend.

  • Points

    Controls the appearance of points in the chart.

    • Point size reduces or increases the size of each data point.

    • Point opacity reduces or increases the opacity of each data point.

    • Input data format interprets the resulting query data. Valid options are:

      • Auto enables automatic selection of long or wide formats.

      • Long uses one field for the series.

      • Wide uses a distinct field for each series.

  • X-axis

    • Scale Valid options are:

      • Linear — a quantitative scale that preserve proportional differences.

      • Logarithmic — a nonlinear quantitative scale particularly useful for plotting data that varies over multiple orders of magnitude.

    • Always show zero checkbox used to include the point 0 on the horizontal axis. If, for example, all values are in the range 100-200, by default the axis will only show that range roughly. But you can force it to extent the axis to 0. That makes it easier to get a sense of the absolute numbers, not just the numbers relative to each other. checkbox

    • Show title checkbox shows a title in the X-Axis.

    • Title Field where to enter a title for the X-Axis.

    • Format value Option available from version 1.176

      Format the values as Raw, Abbreviated or Metric. For example, if the raw formatting is 1,000, abbreviated would be 1K, and metric would be 1k (1 kilo).

  • Y-axis

    • Scale Valid options are:

      • Linear — quantitative scales that preserve proportional differences.

      • Logarithmic — quantitative scales particularly useful for plotting data that varies over multiple orders of magnitude.

    • Always show zero checkbox. Used to include the point 0 on the vertical axis. If, for example, all values are in the range 100-200, by default the axis will only show that range roughly. But you can force it to extent the axis to 0. That makes it easier to get a sense of the absolute numbers, not just the numbers relative to each other.

    • Show title checkbox shows a title in the Y-Axis. checkbox.

    • Title Field where to enter a title to the Y-Axis.

    • Format value Option available from version 1.176

      Format the values as Raw, Abbreviated or Metric. For example, if the raw formatting is 1,000, abbreviated would be 1K, and metric would be 1k (1 kilo).

  • Trend line toggle sets a line or curve that estimates the relationship between X and Y values. In some cases, a straight line is the best fit. But there might be cases where other types of graphs better estimate the relationship.

    • Regression type applies when Trend line is enabled. Used to set the regression type to visualize in the chart. Valid options are:

      • Linear — a straight line described by the formula y = ax +b

      • Logarithmic — y = a + b * log(x)

      • Exponential — y = a + e(b * x)

      • Power — y = a * xb

      • Quadratic — y = a + b * x + c * x2

      • Polynomial — y = a + b * x + ... * x^order

  • Series assigns a color to the series and provide a title for the series to be displayed in chart.