SciPy

Trajectory results

Trajectory results are simply a vehicle to output full trajectories of tracers (even though they are never stored in memory over the full cosmic time). The user can choose whether to output only radial information or also full 3D positions and velocities. As trajectory information quickly becomes very large, this result should typically only be switched on for one or a few halos (see Run-time configuration parameters for how to set such instructions).

Compile-time parameters

Parameter

Explanation

OUTPUT_RESULT_TRAJECTORY

Write trajectory results to output file

OUTPUT_RESULT_TRAJECTORY_R

Save the tracer’s radius along the trajectory

OUTPUT_RESULT_TRAJECTORY_VR

Save the tracer’s radial velocity along the trajectory

OUTPUT_RESULT_TRAJECTORY_VT

Save the tracer’s tangential velocity along the trajectory

OUTPUT_RESULT_TRAJECTORY_X

Save the tracer’s full 3-dimensional coordinates along the trajectory

OUTPUT_RESULT_TRAJECTORY_V

Save the tracer’s full 3-dimensional velocity along the trajectory

Run-time parameters

This result does not add any config parameters.

Output fields

Field

Type

Dimensions

Exists if

Explanation

halo_first

int64

n_halos

Always

The index of the first result for each halo (or -1 if none exists for a halo).

halo_n

int32

n_halos

Always

The number of results of this type for each halo (can be 0).

tracer_id

int64

n_rs_trajectory

Always

The ID of the tracer to which this result refers.

first_snap

int16

n_rs_trajectory

Always

The first snapshot where the trajectory was recorded.

last_snap

int16

n_rs_trajectory

Always

The last snapshot where the trajectory was recorded.

r

float

n_rs_trajectory * 3

OUTPUT_RESULT_TRAJECTORY_R

The radius of the tracer as a function of time.

vr

float

n_rs_trajectory * 3

OUTPUT_RESULT_TRAJECTORY_VR

The radial velocity as a function of time.

vt

float

n_rs_trajectory * 3

OUTPUT_RESULT_TRAJECTORY_VT

The tangential velocity as a function of time.

x

float

n_rs_trajectory * 3

OUTPUT_RESULT_TRAJECTORY_X

The relative coordinates as a function of time; r is implicit in this field.

v

float

n_rs_trajectory * 3

OUTPUT_RESULT_TRAJECTORY_V

The relative velocity as a function of time; vr is implicit in this field.

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