我有以下代码使用nvd3绘制圆环图，当我将动态objcect数组传递给datanum时，我收到了上述错误。如果我硬编码相同的对象数组格式它正在工作（绘制圆环图）。
代码：
contoller：
$scope.getMentions = function ( ) {
var promise = widgetServices.getMentions( );
promise.then(function (response) {
$rootScope.mentionsData = response.data.facet_counts.facet_pivot.toyota_series; console.log($rootScope.mentionsData); // This is $rootScope data im passing to nvd3.
}, function (errorPayload) { $log.error('failure loading the details', errorPayload); }); }
//Donut chart example
nv.addGraph(function() {
var chart = nv.models.pieChart()
.x(function(d) { return d.value })
.y(function(d) { return d.count })
.showLabels(true) //Display pie labels
//.labelThreshold(.01) //Configure the minimum slice size for labels to show up
.labelType("percent") //Configure what type of data to show in the label. Can be "key", "value" or "percent"
.donut(true) //Turn on Donut mode. Makes pie chart look tasty!
.donutRatio(0.35) //Configure how big you want the donut hole size to be.
;
//chart.height(2000);
d3.select("#chart svg")
.datum($rootScope.mentionsData) //Dynamic data passing from controller
.transition().duration(350)
.call(chart);
return chart;
});
硬编码数组：虚拟数据（图表使用此数据绘制）
exampleData =
[
{
"label": "Camry",
"value" : 248119
} ,
{
"label": "Prius",
"value" : 246203
} ,
{
"label": "Corolla",
"value" : 97891
} ,
{
"label": "Tacoma",
"value" : 57181
} ,
{
"label": "Mirai",
"value" : 53723
} ,
{
"label": "Highlander",
"value" : 45351
} ,
{
"label": "Tundra",
"value" : 43394
} ,
{
"label": "4Runner",
"value" : 38147
},
{
"label": "RAV4",
"value" : 34563
},
{
"label": "Matrix",
"value" : 31071
},
{
"label": "Avalon",
"value" : 22596
}
];