How to invoke angularjs function from external js file - d3 chart

I have below code in Angularjs javascript file which is powering d3js radar chart

chart.js

ui.d3.TsPlot = function(element) {
  this._element = element;
  this._plotRadius = 41;
  this._padding = 7;
  this._interpolation = 'linear-closed';
  this._editable = false;
  this._tooltips = true;
  this._animated = true;
  this._freeDraw = false;
  this._exps = [];
.........
};

ui.tsplot = function() {
       function link(scope, element, attrs) {
       var tsPlot = new ui.d3.TsPlot(element[0])
      .setPlotRadius(parseInt(attrs.plotRadius, 10))
       .setInnerRadius(parseInt(attrs.innerRadius, 10))
     // Some other assignments for TsPlot
  }
}

angular
 .module('ui.tsplot', [])
 .directive('tsPlot', ui.tsplot);

I would like to call tsplot() in my javascript function in the template.

home.html

  <script type="text/javascript">
   function retry()
    {
            alert('Before assignment');
            var scope = angular.element(document.getElementById("tsPlot")).scope();
            scope.ui.tsplot();
            alert('After assignment');
    }

However second alert never runs when I invoke retry() function, when I checked the console, browser throws an error as "Uncaught TypeError: Cannot read property 'ui' of undefined"

Below code I use in my template

 <script>
        var app = angular.module('tsPlotExampleApp', ['ui.tsplot']);
        app.controller('tsPlotCtrl', function ($scope) {
        $scope.dyndata={};
   });
</script>

What am I missing in retry(), what should I do to invoke ui.tsplot() in retry?

Objective of this is to load the d3 function as I have dynamically created the charts.