# HB Chorochronic duplication¶

Computes the chorochronic duplication of a HB/TSM computation.

## Parameters¶

• base: `Base`

The input base that will be chorochronically duplicated.

• coordinates: list(str)

The variable names that define the set of coordinates used for the duplication. It is assumed that they are cartesian coordinates.

• vectors: list(tuple(str)), default= []

If the base contains vectors, they must be rotated, so put them here. It is assumed that they are expressed in the cartesian coordinate system.

• hb_computation: :class:`.HbComputation or in_attr, default= ‘in_attr’

The object that defines the attributes of the current HB/TSM computation.

• nb_duplication: int or in_attr, default= ‘in_attr’

The number of duplications.

• pitch: int or float or in_attr, default= ‘in_attr’

The pitch of the current row.

• omega: int or float or in_attr, default= 0.

Rotation speed expressed in radians per second so that the mesh can be rotated accordingly.

• time: float, default= 0.

Time instant at which solution is sought.

## Initialization¶

To initialize a Chorochronic duplication object:

```>>> treatment = Treatment('hbchoro')
```

## Main functions¶

class antares.hb.TreatmentHbchoro.TreatmentHbchoro
execute()

Execute the treatment.

Returns

the base containing the results

Return type

`Base`

## Example¶

```"""
This example illustrates the chorochronic duplication
treatment on a single frequency (TSM) computation
"""
import os
if not os.path.isdir('OUTPUT'):
os.makedirs('OUTPUT')

import numpy as np

from antares import HbComputation, Reader, Treatment, Writer

# ------------------
# ------------------
reader['filename'] = os.path.join('..', 'data', 'HARMONIC_BALANCE', 'flow_<zone>.dat')

# -------------------------------
# Create an HbComputation object
# -------------------------------
# AEL configuration with IBPA = 8 and nb_blade = 20
hb_comp = HbComputation()
hb_comp['frequencies'] = [6.2344674e-04]
hb_comp['phaselag'] = [2 * np.pi * 8. / 20.]
ini_base.attrs['hb_computation'] = hb_comp

# ------------
# Duplication
# ------------
treatment = Treatment('hbchoro')
treatment['base'] = ini_base
treatment['vectors'] = [('rovx', 'rovy', 'rovz')]
treatment['nb_duplication'] = 20
treatment['pitch'] = 2. * np.pi / 20.
result = treatment.execute()

# -------------------
# Writing the result
# -------------------
writer = Writer('bin_tp')
writer['filename'] = os.path.join('OUTPUT', 'ex_hbchoro.plt')
writer['base'] = result
writer.dump()
```