TrajectoryPoints?

[cbernet]

Hi everybody,

In papas we have a data structure called path that contains trajectory parameters and points (reference points on the trajectory). We're talking about a purely geometrical object, this is not a track.

The number of points is arbitrary but limited to ~10, and the points are indexed by a name (e.g. vertex, ecal_entrance, ..). We would like to store such objects in the FCC EDM.

We thought about the following. What do you think? wouldn't a fixed size array of points be more adequate in fcc::TrajectoryPoints? Do we have such a thing? Indeed, we think it is better to have concrete storage of the points within fcc::TrajectoryPoints rather than in a separate collection.

fcc::Helix:
   # here helix parameters
  OneToOneRelations:
  - fcc::TrajectoryPoints points

fcc::StraightLine:
   # here straightline parameters
  OneToOneRelations:
  - fcc::TrajectoryPoints points

fcc::TrajectoryPoints: 
  OneToManyRelations:
  - fcc::Point points 

Cheers,

Colin, @alicerobson

[alicerobson]

Hi Colin

Have I missed something? How is the name that is associated with each point to be stored using your proposal?

"the points are indexed by a name (e.g. vertex, ecal_entrance, ..)"

Alice

On 01 Dec 2016, at 11:22, Colin Bernet notifications@github.com wrote:

Hi everybody,

In papas we have a data structure called path that contains trajectory parameters and points (reference points on the trajectory). We're talking about a purely geometrical object, this is not a track.

The number of points is arbitrary but limited to ~10, and the points are indexed by a name (e.g. vertex, ecal_entrance, ..). We would like to store such objects in the FCC EDM.

We thought about the following. What do you think? wouldn't a fixed size array of points be more adequate in fcc::TrajectoryPoints? Do we have such a thing? Indeed, we think it is better to have concrete storage of the points within fcc::TrajectoryPoints rather than in a separate collection.

fcc::Helix:

here helix parameters

OneToOneRelations:

• fcc::TrajectoryPoints points

fcc::StraightLine:

here straightline parameters

OneToOneRelations:

• fcc::TrajectoryPoints points

fcc::TrajectoryPoints: OneToManyRelations:

• fcc::Point points Cheers,

Colin, @alicerobson https://github.com/alicerobson — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/HEP-FCC/fcc-edm/issues/31, or mute the thread https://github.com/notifications/unsubscribe-auth/ANqb2oQBUFicQ0LNVV3Lyzj6YLp_oe_9ks5rDp_5gaJpZM4LBN-7.

[jlingema]

Hi Colin and Alice,

Sorry for only answering now, I missed this somehow.

We now (since podio v0.6) have the possibility to store arrays, but it was only tested for builtin types. There is a small bug fix necessary to make it also work for PODs (components), PR soon. So something like this should be feasible:

components:
fcc::TrajectoryPoints: 
  points: std::array<fcc::Point, 10>

datatypes: 
fcc::Helix:
   # here helix parameters
  Members:
  - fcc::TrajectoryPoints points

fcc::StraightLine:
   # here straightline parameters
  Members:
  - fcc::TrajectoryPoints points

However, is it really fixed size? Regarding Alice's question, I guess that could be solved by an enum?

Cheers, Joschka

[cbernet]

Hi Joschka, an enum could be good but is there a way to declare that with podio?

[jlingema]

No. After writing I also began wondering about how to make this work without risking to go out of synch.

[jlingema]

Although, I guess one could use the ExtraCode but I guess that was not it's intended usage, @hegner?

[jlingema]

To elaborate on that, something like this does work:

fcc::TrajectoryPoints: 
  points: std::array<fcc::Point, 10>
  ExtraCode :
      declaration: "
      enum class PointType : int { kVertex, kEcalEntrance, ...};"

[cbernet]

Cool!

Le 7 avr. 2017 à 09:26, Joschka Lingemann notifications@github.com a écrit :

To elaborate on that, something like this does work:

fcc::TrajectoryPoints:

• std::array<fcc::Point, 10> points ExtraCode : declaration: " enum class kPoint : int { vertex, ecal_entrance, ...};" — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/HEP-FCC/fcc-edm/issues/31#issuecomment-292462538, or mute the thread https://github.com/notifications/unsubscribe-auth/AD8ku4as-dxCyXTHJ5fe9_g2fyqssdSoks5rteUtgaJpZM4LBN-7.