From 8adb9c18dc377ca5e746fce1a0f5c1ec46f6c7a2 Mon Sep 17 00:00:00 2001
From: Gamelin Alexis <alexis.gamelin@synchrotron-soleil.fr>
Date: Thu, 29 Jul 2021 11:26:34 +0200
Subject: [PATCH] Add BeamSpectrumMonitor
Add a monitor for the coherent beam spectrum (i.e. coupled bunch modes).
Add utility functions to BunchSpectrumMonitor to know the fft and signal resolution.
Save the frequency samples for BunchSpectrumMonitor in the hdf5 file.
---
tracking/monitors/__init__.py | 3 +-
tracking/monitors/monitors.py | 232 +++++++++++++++++++++++++++++++++-
2 files changed, 231 insertions(+), 4 deletions(-)
diff --git a/tracking/monitors/__init__.py b/tracking/monitors/__init__.py
index ffff2a9..3f1f9d7 100644
--- a/tracking/monitors/__init__.py
+++ b/tracking/monitors/__init__.py
@@ -12,7 +12,8 @@ from mbtrack2.tracking.monitors.monitors import (Monitor, BunchMonitor,
WakePotentialMonitor,
TuneMonitor,
CavityMonitor,
- BunchSpectrumMonitor)
+ BunchSpectrumMonitor,
+ BeamSpectrumMonitor)
from mbtrack2.tracking.monitors.plotting import (plot_bunchdata,
plot_phasespacedata,
plot_profiledata,
diff --git a/tracking/monitors/monitors.py b/tracking/monitors/monitors.py
index 5b70c9b..8c2271c 100644
--- a/tracking/monitors/monitors.py
+++ b/tracking/monitors/monitors.py
@@ -1089,6 +1089,15 @@ class BunchSpectrumMonitor(Monitor):
allow several cores to write in the same file at the same time.
If False, open the HDF5 file in standard mode.
+ Attributes
+ ----------
+ fft_resolution : float
+ Return the fft resolution in [Hz].
+ signal_resolution : float
+ Return the signal resolution in [Hz].
+ frequency_samples : array of float
+ Return the fft frequency samples in [Hz].
+
Methods
-------
track(bunch):
@@ -1146,9 +1155,37 @@ class BunchSpectrumMonitor(Monitor):
self.incoherent = np.zeros((3, self.n_fft//2+1, buffer_size))
self.coherent = np.zeros((3, self.n_fft//2+1, buffer_size))
+ self.file[self.group_name].create_dataset(
+ "freq", data=self.frequency_samples)
+
+ @property
+ def fft_resolution(self):
+ """
+ Return the fft resolution in [Hz].
+
+ It is defined as the sampling frequency over the number of samples.
+ """
+ return self.ring.f0/self.n_fft
+
+ @property
+ def signal_resolution(self):
+ """
+ Return the signal resolution in [Hz].
+
+ It is defined as the inverse of the signal length.
+ """
+ return 1/(self.ring.T0*self.save_every)
+
+ @property
+ def frequency_samples(self):
+ """
+ Return the fft frequency samples in [Hz].
+ """
+ return rfftfreq(self.n_fft, self.ring.T0)
+
def track(self, object_to_save):
"""
- Save positions and mean data.
+ Save spectrum data.
Parameters
----------
@@ -1227,7 +1264,7 @@ class BunchSpectrumMonitor(Monitor):
Returns
-------
incoherent : array
- The average of the transformed input in each plane.
+ Bunch incoherent spectrum.
"""
fourier = rfft(positions, n=self.n_fft)
@@ -1243,7 +1280,196 @@ class BunchSpectrumMonitor(Monitor):
Returns
-------
coherent : array
- The average of the transformed input in each plane.
+ Bunch coherent spectrum.
+
+ """
+ coherent = np.abs(rfft(mean, n=self.n_fft))
+
+ return coherent
+
+class BeamSpectrumMonitor(Monitor):
+ """
+ Monitor coherent beam spectrum.
+
+ Parameters
+ ----------
+ ring : Synchrotron object
+ n_fft : int or float, optional
+ The number of points used for FFT computation, if n_fft is bigger than
+ save_every zero-padding is applied.
+ file_name : string, optional
+ Name of the HDF5 where the data will be stored. Must be specified
+ the first time a subclass of Monitor is instancied and must be None
+ the following times.
+ save_every : int or float, optional
+ Set the frequency of the save. The spectrum is computed saved every
+ save_every call of the montior.
+ buffer_size : int or float, optional
+ Size of the save buffer.
+ total_size : int or float, optional
+ Total size of the save. The following relationships between the
+ parameters must exist:
+ total_size % buffer_size == 0
+ number of call to track / save_every == total_size - 1
+ mpi_mode : bool, optional
+ If True, open the HDF5 file in parallel mode, which is needed to
+ allow several cores to write in the same file at the same time.
+ If False, open the HDF5 file in standard mode.
+
+ Attributes
+ ----------
+ fft_resolution : float
+ Return the fft resolution in [Hz].
+ signal_resolution : float
+ Return the signal resolution in [Hz].
+ frequency_samples : array of float
+ Return the fft frequency samples in [Hz].
+
+ Methods
+ -------
+ track(bunch):
+ Save tune and/or FFT data.
+
+ """
+
+ def __init__(self, ring, n_fft=10000,
+ file_name=None, save_every=10,
+ buffer_size=5, total_size=10, mpi_mode=True,
+ dim="all"):
+
+ self.n_fft = int(n_fft)
+ self.store_dict = {"x":0,"y":1,"tau":2}
+
+ if dim == "all":
+ self.track_dict = {"x":0,"y":1,"tau":2}
+ self.mean_index = [True, False, True, False, True, False]
+ elif dim == "tau":
+ self.track_dict = {"tau":0}
+ self.mean_index = [False, False, False, False, True, False]
+ elif dim == "x":
+ self.track_dict = {"x":0}
+ self.mean_index = [True, False, False, False, False, False]
+ elif dim == "y":
+ self.track_dict = {"y":0}
+ self.mean_index = [False, False, True, False, False, False]
+
+ self.size_list = len(self.track_dict)
+
+ self.ring = ring
+ group_name = "BeamSpectrum"
+
+ dict_buffer = {"coherent":(3, n_fft//2+1, buffer_size)}
+ dict_file = {"coherent":(3, n_fft//2+1, total_size)}
+
+ self.monitor_init(group_name, save_every, buffer_size, total_size,
+ dict_buffer, dict_file, file_name, mpi_mode)
+
+ self.dict_buffer = dict_buffer
+ self.dict_file = dict_file
+
+ self.save_count = 0
+
+ self.mean = np.zeros((self.size_list, ring.h, save_every))
+ self.coherent = np.zeros((3, self.n_fft//2+1, buffer_size))
+
+ self.file[self.group_name].create_dataset(
+ "freq", data=self.frequency_samples)
+
+ @property
+ def fft_resolution(self):
+ """
+ Return the fft resolution in [Hz].
+
+ It is defined as the sampling frequency over the number of samples.
+ """
+ return self.ring.f1/self.n_fft
+
+ @property
+ def signal_resolution(self):
+ """
+ Return the signal resolution in [Hz].
+
+ It is defined as the inverse of the signal length.
+ """
+ return 1/(self.ring.T0*self.save_every)
+
+ @property
+ def frequency_samples(self):
+ """
+ Return the fft frequency samples in [Hz].
+ """
+ return rfftfreq(self.n_fft, self.ring.T1)
+
+ def track(self, beam):
+ """
+ Save mean data.
+
+ Parameters
+ ----------
+ beam : Beam object
+
+ """
+ if (beam.mpi_switch == True):
+ bunch_num = beam.mpi.bunch_num
+ bunch = beam[bunch_num]
+ self.mean[:, bunch_num, self.buffer_count] = bunch.mean[self.mean_index]
+ else:
+ self.mean[:, :, self.buffer_count] = beam.bunch_mean[self.mean_index,:]
+
+ self.save_count += 1
+
+ if self.track_count > 0 and self.track_count % self.save_every == 0:
+ self.to_buffer(beam)
+ self.save_count = 0
+
+ self.track_count += 1
+
+ def to_buffer(self, beam):
+ """
+ A method to hold saved data before writing it to the output file.
+
+ """
+
+ self.time[self.buffer_count] = self.track_count
+
+ for key, value in self.track_dict.items():
+ if (beam.mpi_switch == True):
+ data_core = self.mean[value, beam.mpi.bunch_num, :]
+ full_data = beam.mpi.comm.allgather(data_core)
+ data = np.reshape(full_data, (-1), 'F')
+ else:
+ data = np.reshape(self.mean[value, :, :], (-1), 'F')
+ self.coherent[self.store_dict[key],:,self.buffer_count] = self.get_beam_spectrum(data)
+ self.buffer_count += 1
+
+ if self.buffer_count == self.buffer_size:
+ self.write()
+ self.buffer_count = 0
+
+ def write(self):
+ """
+ Write data from buffer to output file.
+
+ """
+ self.file[self.group_name]["time"][self.write_count*self.buffer_size:(
+ self.write_count+1)*self.buffer_size] = self.time
+
+ self.file[self.group_name]["coherent"][:,:,
+ self.write_count * self.buffer_size:(self.write_count+1) *
+ self.buffer_size] = self.coherent
+
+ self.file.flush()
+ self.write_count += 1
+
+ def get_beam_spectrum(self, mean):
+ """
+ Compute the beam coherent spectrum i.e. the absolute value of the FT
+ of the mean position of every bunch.
+
+ Returns
+ -------
+ coherent : array
+ The beam coherent spectrum.
"""
coherent = np.abs(rfft(mean, n=self.n_fft))
--
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