tuhinkarmakar3882 commented on issue #20868: URL: https://github.com/apache/echarts/issues/20868#issuecomment-2762225989
FYI. Just found this [JSFiddle Link for HighCharts](https://jsfiddle.net/gh/get/library/pure/highcharts/highcharts/tree/master/samples/highcharts/yaxis/type-log-negative/) which showcases, Log Axis with Negative values. Can we take any inspiration from here? > At the core, the script listens for the axis initialization event. When an axis is created and if it is a logarithmic axis with the custom option enabled (allowNegativeLog: true), the extension adjusts several core functions. First, it disables the usual constraint that only positive values are permitted, allowing the chart to process negative inputs without errors. > > Two key functions are overridden: the conversion from logarithmic to linear space (log2lin) and its inverse (lin2log). In these functions, the absolute value of the input is used to perform the logarithmic transformation. Additionally, if the value is negative, the result of the transformation is negated. There are also adjustments for numbers less than 10, ensuring that the conversion produces a smoother transition between negative and positive values. > > Another significant change is made to how tick positions are calculated on the logarithmic axis. The method for determining tick marks (getLogTickPositions) is wrapped with custom logic that accounts for negative values. Instead of using the standard procedure—which would normally exclude negative values—the extension generates tick positions symmetrically for negative and positive parts of the axis, ensuring that the ticks are appropriately placed even when the data spans both sides of zero. > > Finally, the code demonstrates the usage of the modified axis by creating a Highcharts chart. In the chart configuration, the y-axis is set to a logarithmic type and the custom option is enabled. The data series includes a range of values from -1000 to 1000, illustrating how the chart can now display both negative and positive values on a logarithmic scale. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
