{"id":11124,"date":"2020-02-07T09:00:17","date_gmt":"2020-02-07T14:00:17","guid":{"rendered":"https:\/\/blogs.mathworks.com\/pick\/?p=11124"},"modified":"2020-02-24T15:31:46","modified_gmt":"2020-02-24T20:31:46","slug":"spider-plot-ii-custom-charts-intro","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/pick\/2020\/02\/07\/spider-plot-ii-custom-charts-intro\/","title":{"rendered":"Spider Plot II – Custom Charts (Intro)"},"content":{"rendered":"
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Sean<\/a>‘s pick this week is spider_plot<\/tt><\/a> by Moses<\/a>.<\/p>\n

Contents<\/h3>\n
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    \n
  • Custom Charts<\/a><\/li>\n
  • Using the Custom Chart<\/a><\/li>\n
  • Comments<\/a><\/li>\n<\/ul>\n<\/div>\n

    Custom Charts<\/a><\/h3>\n

    My pick this week is also spider_plot<\/tt> which Jiro picked a few months ago<\/a>. Jiro added argument validation, of which we’re obviously big fans(!), to it. Here, I’m going to take it a step further and create a custom chart<\/a> for it; this is also a new R2019b feature.<\/p>\n

    If you look at the signature for spider_plot<\/tt> now, it does not return an output argument. If you want to change it after it’s created, you either need to find the underlying graphics objects using findobj<\/tt> and adjust them, or delete and recreate the chart, probably by clearing the axes with cla<\/tt>. The pieces of the spider_plot may show up in the graphics hierarchy, but the spider_plot itself will not. Because they’re not encapsulated, a user could corrupt them accidentally or struggle to make a change that looks like what they want.<\/p>\n

    By creating a custom chart we get the benefits of encapsulation, our object appearing in the graphics hierarchy, automatic input handling, and give a chart user the same experience they would have with a MathWorks authored chart (e.g. confusionchart<\/tt><\/a>, heatmap<\/tt><\/a>). Additionally, and possibly most importantly, by creating a custom chart, we can tie into the automatic updates in the graphics system hierarchy caused by drawnow<\/tt> in order to be efficient about updates.<\/p>\n

    Using the Custom Chart<\/a><\/h3>\n

    Over the holiday downtime, I converted Moses’ spider_plot<\/tt> to a custom chart, I’ve creatively named SpiderChart<\/tt>. Today, let’s just play with the finished chart.<\/p>\n

    s = SpiderChart(rand(3,5))<\/pre>\n
    s = \r\n\r\n  SpiderChart with properties:\r\n\r\n                   P: [3\u00d75 double]\r\n        AxesInterval: 3\r\n       AxesPrecision: 1\r\n          AxesLimits: []\r\n          FillOption: off\r\n    FillTransparency: 0\r\n               Color: [7\u00d73 double]\r\n           LineStyle: '-'\r\n           LineWidth: 2\r\n              Marker: 'o'\r\n          MarkerSize: 8\r\n       LabelFontSize: 10\r\n        TickFontSize: 10\r\n          AxesLabels: [1\u00d7100 string]\r\n          DataLabels: [1\u00d7100 string]\r\n            Position: [0.1300 0.1100 0.7750 0.8150]\r\n               Units: 'normalized'\r\n\r\n  Use GET to show all properties\r\n\r\n<\/pre>\n
    <\/p>\n
    You can see that the returned object is a SpiderChart<\/tt>. Now, let’s adjust the filling:<\/p>\n
    s.FillOption = 'on'<\/span>;\r\ns.FillTransparency = 0.5;<\/pre>\n
    <\/p>\n
    And adjust the label of the third axis.<\/p>\n
    s.AxesLabels(3) = \"I'm three!\"<\/span>;<\/pre>\n
    <\/p>\n
    What about if the data change?<\/p>\n
    s.P = randn(2,6);<\/pre>\n
    <\/p>\n
    See how everything updated for this?<\/p>\n
    s.DataLabels = [\"MATLAB\"<\/span> \"Simulink\"<\/span>];\r\nlegend show<\/span><\/pre>\n
    <\/p>\n
    Next week<\/a>, we’ll look at authoring the custom chart!<\/p>\n
    Comments<\/a><\/h3>\n
    Do you have a use for custom charts or a chart you would like MathWorks to make?<\/p>\n
    Give it a try and let us know what you think here<\/a> or leave a comment<\/a> for Moses.<\/p>\n