time interval between elements of a group

[julilopez]

I create a group based on a spritesheet and random. 

 

I want a timespan whenever my group elements are generated occur.

 

this.circles= this.add.group();



for (var numCircles = 0; numCircles < 50; numCircles++) { 

            randomCircle = this.game.rnd.integerInRange(0, 10),  

            circle = this.circles.create(this.randomWorldX(), this.randomWorldY(), "circlesImage", randomCircle);            

            this.circles.forEach(this.distanceCircle(), this); 

         } 



this.circles.setAll("body.velocity.x", - 100); 

distanceCircle: function(circles) { 

        var positionX = this.circle.position.x;         

        positionX = positionX * positionX; 

   

        var positionY = this.circle.position.y; 

        positionY = positionY * positionY; 

   

        if (Math.sqrt( positionX + positionY ) < 40 ) { 

            this.circle.reset(this.randomWorldX(), this.randomWorldY()); 

            this.circles.forEach(separate, this); 


} 

But this returns the following error: 

 

Uncaught TypeError: Can not call method 'apply' of undefined. 

 

Thanks.