CircosJS has several types of tracks :
To add a track to your circos instance you should write something like this:
instance.heatmap(
'my-heatmap',
{
// your heatmap configuration
},
heatmap_data
);
This pattern is similar to all track types:
instance.trackType('track-name', configuration, data);
About the track name:
heatmap-1
Note: As written just above, the track name is used as a class name so you should not use spaces and weird characters and first character should not be a digit.