Longitude latitude dynamic data

Ionic Framework
#1

Hello,

I want to assign dynamic values to two points on my map.

The code :

ngOnInit() {
      this.loadMap();
    this.sub = this.route.params.subscribe(params => {
      this.id = params['id'];
      this.latdept = params['latdept'];
      this.lngdept = params['lngdept'];
      this.latarr = params['latarr'];
      this.lngarr = params['lngarr'];
      });

And :

position: {
        lat: this.latdept,
        lng: this.lngdept
      }

But nothing is displayed on the map
Thank’s !

#2 
ngOnInit() {
    this.sub = this.route.params.subscribe(params => {
      this.id = params['id'];
      this.latdept = params['latdept'];
      this.lngdept = params['lngdept'];
      this.latarr = params['latarr'];
      this.lngarr = params['lngarr'];
      });

this.loadMap();

}