Ngx-charts: Logarithmic scale for time series line chart

[merinshaji]

Hi,

I have successfully implemented a timeseries line chart using ngx-charts. The timeseries is plotted on the X-axis and the values on Y-axis. Now I have a requirement to change the Y-axis to logarithmic scale.

Any pointers would be appreciated.

Thanks
Merin

[Bhavisha-Sahitya]

I also have the requirement to have logarithmic scale. @merinshaji were you able to find workaround for the time being?

[heyteacher]

Hi,

here's a demo how to implement log scale in line chart based on @chriszrc's comment https://github.com/swimlane/ngx-charts/pull/455#issuecomment-626800581

https://stackblitz.com/edit/swimlane-line-chart-log-scale

• manually apply Math.log10 to series data
• define yAxisTickFormatting with Math.pow function
• define tooltipTemplate and seriesTooltipTemplate templateRef using Math.pow function

Anyway, I submit pull request https://github.com/swimlane/ngx-charts/pull/1420 where yAxisTickFormatting is applied to tooltip values so you don't need to define tooltipTemplate and seriesTooltipTemplate.

IMO, if you define yAxis ticks as apples, pears, rates, pow, etc... you want that tootlip values are displayed as apples, pears, rates, pow, etc...

[Bhavisha-Sahitya]

@heyteacher thanks a lot for the help. The code link helped me understand where exactly to make the changes hence made changes in bar graph accordingly.