[jira] [Commented] (GEOMETRY-30) VectorBuilder?D Classes
[
https://issues.apache.org/jira/browse/GEOMETRY-30?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16938549#comment-16938549
]
Matt Juntunen commented on GEOMETRY-30:
---
[Here|https://github.com/darkma773r/commons-geometry/blob/geometry-32-working/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/threed/RegionBSPTree3D.java#L654]
is an actual example from my geometry-32 working branch where I'm computing
the region barycenter. I use separate doubles for each component to avoid
unnecessary vector creation. This same type of construct is repeated in all of
the other {{RegionBSPTreeXD}} classes.
> VectorBuilder?D Classes
> ---
>
> Key: GEOMETRY-30
> URL: https://issues.apache.org/jira/browse/GEOMETRY-30
> Project: Apache Commons Geometry
> Issue Type: Wish
>Reporter: Matt Juntunen
>Priority: Major
>
> We should add a {{VectorBuilder?D}} class for each dimension. These classes
> would have the same coordinate properties as their corresponding {{Vector}}
> classes but would be mutable. They would be used to build {{Vector}}
> instances from a number of input values without requiring a new instance to
> be created for each step. The primary API should look something like this:
> {code:java}
> public class VectorBuilder2D {
> double getX();
> VectorBuilder2D setX(double);
> double getY();
> VectorBuilder2D setY(double);
> VectorBuilder2D add(Vector2D);
> VectorBuilder2D subtract(Vector2D);
> VectorBuilder2D multiply(double);
> Vector2D toVector();
> }
> {code}
> A good use case for this is computing a centroid:
> {code:java}
> VectorBuilder2D builder = new VectorBuilder2D();
> for (Vector2D pt : points) {
> builder.add(pt);
> }
> builder.multiply(1.0 / points.size());
> Vector2D centroid = builder.toVector();
> {code}
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[jira] [Commented] (GEOMETRY-30) VectorBuilder?D Classes
[
https://issues.apache.org/jira/browse/GEOMETRY-30?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16938578#comment-16938578
]
Gilles Sadowski commented on GEOMETRY-30:
-
bq. avoid unnecessary vector creation.
At some point, it would be useful to create benchmarks (using
[JMH|https://openjdk.java.net/projects/code-tools/jmh/]) so that we can assess
when "unnecessary" equals "costly".
bq. computing the region barycenter.
Isn't that a case for a stream operation?
> VectorBuilder?D Classes
> ---
>
> Key: GEOMETRY-30
> URL: https://issues.apache.org/jira/browse/GEOMETRY-30
> Project: Apache Commons Geometry
> Issue Type: Wish
>Reporter: Matt Juntunen
>Priority: Major
>
> We should add a {{VectorBuilder?D}} class for each dimension. These classes
> would have the same coordinate properties as their corresponding {{Vector}}
> classes but would be mutable. They would be used to build {{Vector}}
> instances from a number of input values without requiring a new instance to
> be created for each step. The primary API should look something like this:
> {code:java}
> public class VectorBuilder2D {
> double getX();
> VectorBuilder2D setX(double);
> double getY();
> VectorBuilder2D setY(double);
> VectorBuilder2D add(Vector2D);
> VectorBuilder2D subtract(Vector2D);
> VectorBuilder2D multiply(double);
> Vector2D toVector();
> }
> {code}
> A good use case for this is computing a centroid:
> {code:java}
> VectorBuilder2D builder = new VectorBuilder2D();
> for (Vector2D pt : points) {
> builder.add(pt);
> }
> builder.multiply(1.0 / points.size());
> Vector2D centroid = builder.toVector();
> {code}
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[jira] [Commented] (GEOMETRY-30) VectorBuilder?D Classes
[
https://issues.apache.org/jira/browse/GEOMETRY-30?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16938701#comment-16938701
]
Gilles Sadowski commented on GEOMETRY-30:
-
In order to figure what is actually necessary, perhaps start with a "minimal"
implementation:
{code}
public class Vector2D {
// ...
public static class Builder {
private double x;
private double y;
private Builder(double x, double y) {
this.x = x;
this.y = y;
}
public Builder create() {
return new Builder(0, 0);
}
public Builder add(double x, double y) {
this.x += x;
this.y += y;
}
public Vector2D build();
}
}
{code}
Then we should benchmark alternative implementations ("Builder" vs vector
addition) in order to e.g. compute a barycenter.
> VectorBuilder?D Classes
> ---
>
> Key: GEOMETRY-30
> URL: https://issues.apache.org/jira/browse/GEOMETRY-30
> Project: Apache Commons Geometry
> Issue Type: Wish
>Reporter: Matt Juntunen
>Priority: Major
>
> We should add a {{VectorBuilder?D}} class for each dimension. These classes
> would have the same coordinate properties as their corresponding {{Vector}}
> classes but would be mutable. They would be used to build {{Vector}}
> instances from a number of input values without requiring a new instance to
> be created for each step. The primary API should look something like this:
> {code:java}
> public class VectorBuilder2D {
> double getX();
> VectorBuilder2D setX(double);
> double getY();
> VectorBuilder2D setY(double);
> VectorBuilder2D add(Vector2D);
> VectorBuilder2D subtract(Vector2D);
> VectorBuilder2D multiply(double);
> Vector2D toVector();
> }
> {code}
> A good use case for this is computing a centroid:
> {code:java}
> VectorBuilder2D builder = new VectorBuilder2D();
> for (Vector2D pt : points) {
> builder.add(pt);
> }
> builder.multiply(1.0 / points.size());
> Vector2D centroid = builder.toVector();
> {code}
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[jira] [Commented] (GEOMETRY-30) VectorBuilder?D Classes
[
https://issues.apache.org/jira/browse/GEOMETRY-30?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17004631#comment-17004631
]
Matt Juntunen commented on GEOMETRY-30:
---
I'm closing this issue since I no longer have a compelling use case for it.
> VectorBuilder?D Classes
> ---
>
> Key: GEOMETRY-30
> URL: https://issues.apache.org/jira/browse/GEOMETRY-30
> Project: Apache Commons Geometry
> Issue Type: Wish
>Reporter: Matt Juntunen
>Priority: Major
>
> We should add a {{VectorBuilder?D}} class for each dimension. These classes
> would have the same coordinate properties as their corresponding {{Vector}}
> classes but would be mutable. They would be used to build {{Vector}}
> instances from a number of input values without requiring a new instance to
> be created for each step. The primary API should look something like this:
> {code:java}
> public class VectorBuilder2D {
> double getX();
> VectorBuilder2D setX(double);
> double getY();
> VectorBuilder2D setY(double);
> VectorBuilder2D add(Vector2D);
> VectorBuilder2D subtract(Vector2D);
> VectorBuilder2D multiply(double);
> Vector2D toVector();
> }
> {code}
> A good use case for this is computing a centroid:
> {code:java}
> VectorBuilder2D builder = new VectorBuilder2D();
> for (Vector2D pt : points) {
> builder.add(pt);
> }
> builder.multiply(1.0 / points.size());
> Vector2D centroid = builder.toVector();
> {code}
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[jira] [Commented] (GEOMETRY-30) VectorBuilder?D Classes
[
https://issues.apache.org/jira/browse/GEOMETRY-30?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16722436#comment-16722436
]
Gilles commented on GEOMETRY-30:
I'm not convinced by the single centroid example method, where we'd spare 4
lines of code.
IMO, it's not worth populating the API with mutable classes that will end up
duplicating the immutable ones.
> VectorBuilder?D Classes
> ---
>
> Key: GEOMETRY-30
> URL: https://issues.apache.org/jira/browse/GEOMETRY-30
> Project: Apache Commons Geometry
> Issue Type: Wish
>Reporter: Matt Juntunen
>Priority: Major
>
> We should add a {{VectorBuilder?D}} class for each dimension. These classes
> would have the same coordinate properties as their corresponding {{Vector}}
> classes but would be mutable. They would be used to build {{Vector}}
> instances from a number of input values without requiring a new instance to
> be created for each step. The primary API should look something like this:
> {code:java}
> public class VectorBuilder2D {
> double getX();
> VectorBuilder2D setX(double);
> double getY();
> VectorBuilder2D setY(double);
> VectorBuilder2D add(Vector2D);
> VectorBuilder2D subtract(Vector2D);
> VectorBuilder2D multiply(double);
> Vector2D toVector();
> }
> {code}
> A good use case for this is computing a centroid:
> {code:java}
> VectorBuilder2D builder = new VectorBuilder2D();
> for (Vector2D pt : points) {
> builder.add(pt);
> }
> builder.multiply(1.0 / points.size());
> Vector2D centroid = builder.toVector();
> {code}
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