code: function(options) {
        inputEx.VectorField.superclass.setOptions.call(this, options);
       
        this.options.dimension = options.dimension || 2;
        this.options.size = options.size || 3;
       
        this.options.fields = [];
        for(var i = 0 ; i < this.options.dimension ; i++) {
           this.options.fields.push({type: 'number', size: this.options.size });
        }
     }
docs: Additional options for VectorField (dimension, size)