main/src/georegression/struct/GeoTuple4D_F64.java
public void plusIP( GeoTuple4D_F64 a ) {
		x += a.x;
		y += a.y;
		z += a.z;
		w += a.w;
	}
public void plusIP( GeoTuple4D_F64 a ) {
		x += a.x;
		y += a.y;
		z += a.z;
		w += a.w;
	}
<p>In-place addition</p>

this.x = this.x + a.x;

@param a value which is to be added