helgasoft commented on issue #19182: URL: https://github.com/apache/echarts/issues/19182#issuecomment-1756214576
@Ovilia, thank you for replying. Hope other developers would also participate in the conversation. My view is strictly API and UI driven, did not analyze source code. ## The present Radar chart is working, it's a simple chart with few customisations available. But the most important, **tooltips**, is flawed because of [series-radar.data](https://echarts.apache.org/en/option.html#series-radar.data) structure. When people try to customize tooltips (#19004), they find **dataIndex** unusable. See [Demo Code](https://echarts.apache.org/examples/en/editor.html?c=radar&code=PYBwLglsB2AEC8sDeAoWtJgDYFMBcyGOAHmAQOQBCAhgM4QDGsAStQCbUBOsAwgBZcw5WAF8ANGgzBgWSCAJJxkzuy4LJ6CNDaNqYYJwIBtDekLRqAW3yxyAZWq5a5MbGjBL1YgQBsAVgAGANEJMzMkNysbcgBBNkstCFowFUgYFzcPLwIARh8g4KUw9AiLawoASWgAMwNPNLgAFRwGPncsYABzAE8M909vWABmAsLQ4tKoih4AV2SPHG47GZAQAyFXfuzhgA4CkNMSyPLbHj0cToNezazBvwAmfaKJ4-iAWS4AaxxIaE6-24Ee6BIKiUwAXXG6BSEE6nUWAFEAG44aBkDCcGY4cbPWiLCA4WjGUyoYqvCh4zgE2ivFyHDDdEDRFQcTh0skcMDUYlkkr0sJIxxY4wAFkerhGQVcAFp7gBOBVyiUggKuWIZHI5PZBSH8sxlaIxLAdBjnNiwSgzNjwoR6kT03Vk_QyOQKWB6gD0HtqnHqYEWFCQACMROzeT6_QHYCAEAA-QicH4zThwcic6hVNgkWwAahAADp05mSABue1k55hGbQCAozi0RyNFTQegNBSo6hB3BsPApLHlswD8EoEQloA) for this and other oddities like: - [radar.indicator](https://echarts.apache.org/en/option.html#radar.indicator) usually needs a **max** value because it cannot evaluate axis data, as parallelAxis does. Without _max_ radar points go to arbitrary positions (!). - indicators cannot handle **categorical** values, as parallelAxis does. - indicators have only names but not **labels**, as parallelAxis does. We have to rely on tooltips to find out what the values are. One indicator range could be 1K to 1M, the next -1M to 0. - indicator names have a strange uncustomizable tooltip that just repeats the name (?), and only after _triggerEvent_ is set to true (?) - _universalTransition_ under doubt: I could not morph into bars because of series-radar.data structure ## A better radar chart I consider [radar](https://echarts.apache.org/en/option.html#radar) an axis, like [parallelAxis](https://echarts.apache.org/en/option.html#parallelAxis). There are many similarities between them, one notable difference being the layout - radar is radial, parallelAxis is horizontal. I also like polar's [angleAxis](https://echarts.apache.org/en/option.html#angleAxis) for the ability to display simple **line** series with their **points** (parallelAxis doesn't do points). Please note also that both polar and parallel charts have their own **coordinateSystem**. So the goal would be to **merge** angleAxis with parallelAxis for a new better radarAxis. Once this is accomplished, we would start using series-line with ```coordinateSystem:'radar'``` and ```radarIndex:0```, and series-radar will become obsolete. Advantages: - simpler, more consistent API - support for _dataset_, see [parallel Demo](https://echarts.apache.org/examples/en/editor.html?code=CYQwLiAEC8kNoChLwOQEEUBpIBYB0A7AEwBsO2JeAHEQJwkC6mSqAQlpAIx6kCs5uPDgAMBRs2RwUAYQ5E8tWgWz4SBWgGYmLKQBEO3YcM7ZePWkSLbJKAKIdVJXr2wa8vAlUYIGAbgQIAPYADmAAloEAdjCQAN4sYIGBADbhwQBccZAAvhKQwSAATiDJyQCmyWgAHmEAzpmIyMixkMBhALaZwtiRIO1lmShVHGAAnsEDkCgAxuBlAOaBhaMoOXnNrR2ZJpC9_YMraywbbZ2QRD19kygAXqvZLNaQtWWFYWX18Mdx38hjE4MCsVShUsL9IMkwpEygBlMblTItADuYWAYAAFpkcEcmk0APR40AQTJEqCQAmQEq1QKQJFLADWtXBiRSaURkHByAJADMlu1wGBXoNYgAjbJg3G43mFflgQWFTLBGAAPiyhTKYAAroVoihSQBJSLAMpVKYAamCeANRpNvgekpy31yjzypJeYAaLWp2umk1JOW02V8QA) - support for categorical data - customizable tooltips - simple universalTransition to other charts That is my opinion, other's are readily welcome. -- 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]
