Visualization directive for a histogram

Thanks for the answer. I got it to work but now when I hover over a bar, I get a 'Uncaught TypeError: self.formatter is not a function' error. I'm guessing that a certain setting is missing to fix or disable the hover.

$scope.myVisData = {
   series: [{
        aggId:"1",
        aggLabel:"Root Errors",
        label:"Root Errors",
        values: [
         { x: 1521654330000, y: 1},
         { x: 1521654360000, y: 5},
         { x: 1521654390000, y: 2},
         { x: 1521654320000, y: 4}
        ]
      }
      ]
    };