Value Axis Options¶
MongoDB Charts offers several customization options which modify the representation of a chart's X and Y value axes without affecting the formatting of the data points in the visualization.
Max and Min¶
The Max and Min value axis options allow you to specify maximum and minimum values to display on a chart. Any data points with values outside the specified limits appear at the boundaries of the chart. Setting a maximum display value is useful for removing outlying data from the chart and allowing the viewer to focus on more relevant information.
Changing the minimum for bar and column charts from the default of zero is not recommended. Doing so means the length of the bars is no longer proportional to the data point values.
Toggling the Logarithmic Scale switch to the On position causes your chart to use a logarithmic scale instead of a linear scale for data values. Using a logarithmic scale is helpful for showing the percentage change from one value to the next and for charts with a large value differential from smallest to largest. Data sets such as stock market movements, earthquake strength measurements, and global population sizes are good use cases for a logarithmic scale chart.
Logarithmic Scale Considerations¶
- Use the Logarithmic Scale option only with chart data
that consists of either all positive values or all negative values.
If the chart includes a mix of positive and negative values, or if
it includes the value
0, the chart will not render.
- Bar and column charts normally have a baseline of
0, but logarithmic scale charts have a baseline of
log(0)is undefined. As a result, charts with data points between
1do not render well. You can mitigate this effect by setting the axis minimum of the chart to a value greater than zero but smaller than the lowest value in the data set.
The Label Override field allows you to create a custom axis label. Custom labels can be more descriptive than the default labels and help chart viewers quickly grasp the significance of chart data.
The Label Override customization option is available on the
Y value axis for charts in which the author has encoded multiple
data series by mapping more than one field on a given axis.
To customize the axis label for charts that have a single field mapped,
use the Label Override option within that field's customization