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rplotlystacked-bar-chart

Custom hover compare on plotly which will highlight based on category instead of x or y?


I am asking this question as an extension of a previous question. Curiosity lead me to wonder if you could modify the hovermode such that in a stacked percent chart, it will highlight the percent values of all the segments of the same color, one from each bar. Essentially the "x" hover mode in a normal chart. but since we are stacking different values on top of each other the default x mode does not seem to work intuitively this way.

Here is my code. Any help would be appreciated.

dat <- data.frame(group1=(rep(letters[1:4], each=5)), 
           group2=rep(LETTERS[1:5], times=4),
           pct = c(rep(.2, times=5), 
                   c(.1, .1, .1, .3, .4), 
                   c(.2, .2, .2, .3, .1),
                   c(.3, .1, .2, .2, .2))
           )
dat %>%
  plot_ly() %>%
  add_bars(x=~pct, y=~group1,  color=~group2,
           customdata = ~group2,
           hovertemplate = paste0(
             "%{y:.2f%}<br>",
             "<extra>%{customdata}</extra>"
             )
           ) %>% 
      layout(yaxis = list(title = 'Group 1', 
                          autorange='reversed', 
                          categoryorder='trace'),
             xaxis = list(title = 'Percent', tickformat = ".0%"),
             barmode = 'stack', 
             hovermode = 'y',

             legend = list(traceorder = "normal")) %>%
      config(displaylogo = FALSE
             #,modeBarButtonsToRemove = list('hoverCompareCartesian'
             )

Solution

  • Update

    I initially used an HTML button that can be aesthetically controlled. I've updated this answer to include that original working method and a method that uses Plotly's bottons, so that the button can be in the plot space.

    Using HTML Button

    I used a button to trigger this additional hovermode. So that you can turn it off and use other hovermodes as well.

    This uses the library htmlwidgets. This was only tested using a stacked bar chart.

    This includes code to fix the hovermode when Plotly tries to make it x (an issue with stacked bar charts compare mode -- the premise of your previous question).

    I added a lot of CSS for the button that isn't strictly necessary - if you have any questions regarding that part or anything, let me know.

    dat %>%
      plot_ly(height = 450) %>%              # so Plotly makes room for the btn!
      add_bars(x = ~pct, y = ~group1,  color = ~group2,
               split = ~group2, customdata = ~group2,
               hovertemplate = paste0("%{x:.2f%}<br>", "<extra>%{customdata}</extra>")) %>% 
      layout(yaxis = list(title = 'Group 1', autorange = 'reversed', categoryorder = 'trace'),
             xaxis = list(title = 'Percent', tickformat = ".0%"),
             barmode = 'stack', hovermode = 'y', legend = list(traceorder = "normal")) %>%
      config(displaylogo = FALSE) %>% 
      htmlwidgets::onRender(         # <---- I'm new!
        "function(el, x) {
          dv = document.createElement('div');        /* create button parent */
          dv.id = 'dBtn'
          dv.innerHTML = '<btn id=\"hb\" >Click here to compare by color</btn>'
          sty = document.createElement('style');     /* add css to btn */
          sty.innerHTML = `
            #hb {
              padding: 15px 25px;
              color: white;
              font-size: 1.5em;
              background-color: #2A0134;
              box-shadow: 0 9px rgba(0, 0, 0, .35);
              border-radius: 15px;
              cursor: pointer;
            }
            #hb:hover {
              background-color: #0b000e;
            }
            #hb:active {
              background-color: #0b000e;
              box-shadow: 0 5px #666;
              transform: translateY(4px);
            }
            #dBtn {
              position: relative;
              margin: 20px;
              height: 30px;
            }`
          document.querySelector('head').appendChild(sty);
          el.insertBefore(dv, el.firstChild);        /* add button to webpage */
          el.on('plotly_hover', function(d) {        /* when hovering, check hovermode */
            if (el.layout.hovermode !== 'closest' && el.layout.hovermode !== 'y') {
              Plotly.relayout(el.id, {hovermode: 'y'}) /* fix hovermode, if needed */
            }
            if(thatButton === true) {
              tellMe = d.points[0].pointNumber;      /* changes by color */
              gimme = d.points[0].curveNumber;       /* stays the same by color */
              let xlen = el.data[0].x.length;        /* number of stacked bars */
              let thatsIt = [];
              for(i = 0; i < xlen; i++) {            /* make a hover for each bar */
                thatsIt.push({curveNumber: gimme, pointNumber: i})
              }
              Plotly.Fx.hover(el.id, thatsIt); 
            }
          });
          el.on('plotly_unhover', function(d) {             /* reset hovermode if needed */
            if(thatButton === false) {                      /* if color compare off */
              whatIs = el.layout.hovermode;                 /* what's current hovermode */
              Plotly.relayout(el.id, {hovermode: whatIs});  /* reset hovermode to previous */
            }
          })
          hb = document.getElementById('hb');               /* btn location */
          let thatButton = false;                           /* btn toggle */
          hb.addEventListener('click', function() {         /* when btn is clicked */
            if(thatButton === false) {                      /* if off, turn on */
              hb.innerText = 'Click here to stop comparison by color'; /* indicate triggering */
              thatButton = true;
              Plotly.relayout(el.id, {hovermode: 'closest'}) /* switch hovermode, if needed */
            } else {                                         /* if on, turn off */
              hb.innerText = 'Click here to compare by color';  /* change btn text back */
              thatButton = false;
            }
          })
        }")
    

    y or compare hovermode

    compare by color

    closest hovermode

    Using Plotly Button

    Because of Plotly's inherently dynamic and interactive usage, adding pointer or click events to their event heavy space requires the use of their button.

    Using the argument execute = F in buttons, and plotly_buttonclicked in the onRender call, the Plotly button is used to change the hovermode. In the onRender you'll notice that the calls to make and style the button is gone. The content that added a click event to the button is replaced with the plotly_buttoniclicked method.

    In the plot's layout(legend = ... I've added a call to positioning the legend. That's so that the legend and buttons don't overlap if your plot is small. Additionally, adding width = to Plotly() is no longer necessary.

    Last thing I'll mention is regarding the button labels: " Compare by Color " and "End Color Compare", the latter of which is 1 more character in length than the initial label. The whitespace is used so that both labels are centered.

    dat %>%
      plot_ly() %>%
      add_bars(x = ~pct, y = ~group1,  color = ~group2,
               split = ~group2, customdata = ~group2,
               hovertemplate = paste0("%{x:.2f%}<br>", "<extra>%{customdata}</extra>")) %>% 
      layout(yaxis = list(title = 'Group 1', autorange = 'reversed', categoryorder = 'trace'),
             xaxis = list(title = 'Percent', tickformat = ".0%"),
             barmode = 'stack', hovermode = 'y', 
             # set a legend position so buttons and legend don't overlap when you resize the graph
             legend = list(traceorder = "normal", y = .75, yanchor = "bottom"),              # <---- I'm new!
             updatemenus = list(               # using bottom (legend) and top (button) --
                                               #        so buttons won't overlap legend
               list(type = "buttons", y = .7, x = 1.1, xanchor = "center", yanchor = "top", # <---- I'm new!
                    buttons = list(
                 list(label = " Compare by Color ", method = "relayout",
                      args = list(list(hovermode = "closest")), execute = F)   # <--- I'm important
               ))
             )) %>%
      config(displaylogo = FALSE) %>% 
      htmlwidgets::onRender(         # <---- I'm new!
        "function(el, x) {
          let thatButton = false;                             /* btn toggle */
          hb = document.querySelector('[data-unformatted*=\"Color\"]'); /* get btn locale */
          el.on('plotly_buttonclicked', function(d) {         /* defines plotly btn*/
            if(thatButton === false) {                        /* if off, turn on */
              thatButton = true;
              hb.innerHTML = 'End Color Compare';             /* indicate triggering */
              Plotly.relayout(el.id, {hovermode: 'closest'}); /* switch hovermode, if needed */
            } else {                                          /* if on, turn off */
              thatButton = false;
              hb.innerHTML = ' Compare by Color ';            /* change btn text back */
            }
          });
          el.on('plotly_hover', function(d) {        /* when hovering, check hovermode */
            if (el.layout.hovermode !== 'closest' && el.layout.hovermode !== 'y') {
              Plotly.relayout(el.id, {hovermode: 'y'}) /* fix hovermode, if needed */
            }
            if(thatButton === true) {
              tellMe = d.points[0].pointNumber;      /* changes by color */
              gimme = d.points[0].curveNumber;       /* stays the same by color */
              let xlen = el.data[0].x.length;        /* number of stacked bars */
              let thatsIt = [];
              for(i = 0; i < xlen; i++) {            /* make a hover for each bar */
                thatsIt.push({curveNumber: gimme, pointNumber: i})
              }
              Plotly.Fx.hover(el.id, thatsIt); 
            }
          });
          el.on('plotly_unhover', function(d) {             /* reset hovermode if needed */
            if(thatButton === false) {                      /* if color compare off */
              whatIs = el.layout.hovermode;                 /* what's current hovermode */
              Plotly.relayout(el.id, {hovermode: whatIs});  /* reset hovermode to previous */
            }
          });
        }")
    

    v2 buttonology

    enter image description here