Re: [Geotools-devel] [Geoapi-devel] DirectPosition equals()

[Martin D. <mar...@ge...>]

Graham Davis a écrit :
> public boolean equals(Object o) {
>     if (o instanceof DirectPosition || o instanceof DirectPositionImpl)
>         return this.equals((DirectPosition) o, 0);
>     else
>         return false;
> }

Note: the "|| o instanceof DirectPositionImpl" is useless. I suggest to remove it.


> /**
>  * Compares coodinates of Direct Positions and allows a tolerance value in
>  * the comparison. Implementation Note: Parameter has to be of Type
>  * DirectPosition (not DirectPositionImpl), so that the equals method is
>  * found for DirectPosition´s and DirectPositionImpl´s

I suggest to remove the implementation note: it is normal interface programming
and don't really bring info as far as I can see...



> public boolean equals(DirectPosition position, double tol) {
>     int D = position.getDimension();
>     if( D != getDimension() ) return false;
>     for (int i = 0; i < D; ++i) {
>         if (Math.abs(DoubleOperation.subtract(position.getOrdinate(i), this.coordinate[i])) > tol)
>             return false;
>     }
>     return true;
> }

What is DoubleOperation? What are its advantage compared to the usual '-'
operator? position.getOrdinate(i) returns double value anyway, and
Math.abs(double) expect a double anyway.

Additional note: I suggest to replace:

  if (abs(position.getOrdinate(i) - this.getOrdinate(i)) > tol)

by

  if (!(abs(position.getOrdinate(i) - this.getOrdinate(i))) <= tol)

Purpose: consider positions as different if at least one ordinate is Double.NaN.

	Martin