def _measChromaticity(**kwargs):
"""Measure the chromaticity
Parameters
-----------
dfmax - max RF frequency change (within plus/minus), 1e-6
gamma - beam, 3.0/0.511e-3
alphac - momentum compaction factor, 3.62619e-4
wait - 1.5 second
num_points - 5
returns dp/p, nu, chrom
dpp - dp/p energy deviation
nu - tunes
chrom - result chromaticities
obt - orbit at each f settings (initial, every df, final).
"""
dfmax = kwargs.get("dfmax", 1e-6)
gamma = kwargs.get("gamma", 3.0e3 / 0.511)
alphac = kwargs.get("alphac", 3.6261976841792413e-04)
wait = kwargs.get("wait", 1.5)
npt = kwargs.get("num_points", 5)
verbose = kwargs.get("verbose", 0)
eta = alphac - 1 / gamma / gamma
obt = []
f0 = getRfFrequency(handle="setpoint")
nu0 = getTunes()
obt.append(getOrbit(spos=True))
_logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))
# incase RF does not allow large step change, ramp down first
if verbose:
print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(f0, -dfmax, npt))
for df in np.linspace(0, abs(dfmax), npt)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / npt)
f = np.linspace(f0 - dfmax, f0 + dfmax, npt)
nu = np.zeros((len(f), 2), "d")
for i, f1 in enumerate(f):
if verbose > 0:
print("freq= ", f1, end=" ")
putRfFrequency(f1)
time.sleep(wait)
nu[i, :] = getTunes()
obt.append(getOrbit(spos=True))
if verbose > 0:
print(
"tunes:",
nu[i, 0],
nu[i, 1],
np.min(obt[-1][:, 0]),
np.max(obt[-1][:, 0]),
np.min(obt[-1][:, 1]),
np.max(obt[-1][:, 1]),
)
for df in np.linspace(0, abs(dfmax), npt):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / npt)
obt.append(getOrbit(spos=True))
df = f - f0
dnu = nu - np.array(nu0)
p, resi, rank, sing, rcond = np.polyfit(df, dnu, deg=2, full=True)
chrom = p[-2, :] * (-f0 * eta)
if verbose > 0:
print("Coef:", p)
print("Resi:", resi)
print("Chrom:", chrom)
return df / (-f0 * eta), nu, chrom, obt
def measChromaticity(
dfmax=1e-6, gamma=3.0e3 / 0.511, alphac=3.626e-4, num_points=5, fMeasTunes=None, deg=2, wait=0.5, verbose=0
):
"""Measure the chromaticity
Parameters
-----------
dfmax - max RF frequency change (within plus/minus), 1e-6
gamma - beam, 3.0/0.511e-3
alphac - momentum compaction factor, 3.62619e-4
wait - 1.5 second
num_points - 5
fMeasTunes - function used to get tunes. default None, use getTunes().
returns
--------
chrom : chromaticity, (chx, chy)
info : dictionary
freq : list of frequency setting
freq0 : initial frequency setpoint
tune : list of tunes, shape (num_points, 2)
dpp : dp/p energy deviation
obt : orbit at each f settings (initial, every df, final).
deg : degree of polynomial fitting.
p : polynomial coeff, shape (deg+1, 2)
"""
obt = []
f0 = getRfFrequency(handle="setpoint")
# names, x0, y0, Isum0, timestamp, offset = \
# measKickedTbtData(7, (0.15, 0.2), sleep=10, output=False)
# nu0 = (calcFftTunes(x0), calcFftTunes(y0))
nu0 = fMeasTunes() if fMeasTunes else getTunes()
obt.append(getOrbit(spos=True))
# _logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))
# incase RF does not allow large step change, ramp down first
if verbose:
print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(f0, -dfmax, num_points))
for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / num_points)
f = np.linspace(f0 - dfmax, f0 + dfmax, num_points)
nu = np.zeros((len(f), 2), "d")
for i, f1 in enumerate(f):
if verbose > 0:
print("dfreq= {0: .2e}".format(f1 - f0), end=" ")
putRfFrequency(f1)
time.sleep(wait)
nu[i, :] = fMeasTunes() if fMeasTunes else getTunes()
obt.append(getOrbit(spos=True))
if verbose > 0:
print(
"tunes: {0:.5f} {1:.5f}".format(nu[i, 0], nu[i, 1]),
"orbit min-max: {0:.2e} {1:.2e}, {2:.2e} {3:.2e}".format(
np.min(obt[-1][:, 0]), np.max(obt[-1][:, 0]), np.min(obt[-1][:, 1]), np.max(obt[-1][:, 1])
),
)
for df in np.linspace(0, abs(dfmax), num_points):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / num_points)
obt.append(getOrbit(spos=True))
# calculate chrom, return info
info = {"freq": f, "tune": nu, "orbit": obt, "freq0": f0, "deg": deg}
chrom, dpp, p = calcChromaticity(f0, f, nu, deg=deg)
info["dpp"] = dpp
info["p"] = p
return chrom, info
def measDispersion(
elem, dfmax=5e-7, alphac=3.6261976841792413e-04, gamma=5.870841487279844e3, num_points=5, full=False, verbose=0
):
"""measure dispersion at BPMs
Parameters
-----------
elem : BPM name, list or pattern
dfmax : float. frequency change (check the unit)
alphac : float. momentum compaction factor.
gamma : float. beam energy.
num_points : int. points to fit line
full : reserved.
Returns
--------
eta : numpy.array. (nelem, 3) with columns etax, etay and s
Examples
---------
>>> eta = measDispersion('p*c0[1-4]*')
"""
eta = alphac - 1.0 / gamma / gamma
bpmobj = [b for b in getElements(elem) if b.family == "BPM"]
bpmnames = [b.name for b in bpmobj]
nbpm = len(bpmnames)
_logger.info("measure dispersions at %d elements '%s'" % (len(bpmnames), str(elem)))
f0 = getRfFrequency(handle="setpoint")
dflst = np.linspace(-abs(dfmax), abs(dfmax), num_points)
# incase RF does not allow large step change, ramp down first
for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / num_points)
# avoid a bug in virtac
obt0 = getOrbit(bpmnames)
cod = np.zeros((len(dflst), 2 * nbpm), "d")
for i, df in enumerate(dflst):
v0 = getOrbit()
putRfFrequency(f0 + df)
if verbose > 0:
print(i, "df=", df, " f=", f0)
waitStableOrbit(v0)
# repeat the put/get in case simulator did not response latest results
obt = getOrbit(bpmnames)
# print i, obt[0,:2], obt0[0,:2], np.shape(obt), np.shape(obt0)
cod[i, :nbpm] = obt[:, 0] - obt0[:, 0]
cod[i, nbpm:] = obt[:, 1] - obt0[:, 1]
# restore
for df in np.linspace(0, abs(dfmax), num_points):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / num_points)
# fitting
p = np.polyfit(dflst, cod, deg=1)
disp = -p[0, :] * f0 * eta
s = np.array([e.sb for e in bpmobj], "d")
ret = np.zeros((len(bpmobj), 3), "d")
ret[:, 0] = disp[:nbpm]
ret[:, 1] = disp[nbpm:]
ret[:, 2] = s
if verbose > 0:
for i, bpm in enumerate(bpmobj):
print(i, bpm.name, bpm.sb, ret[i, 0], ret[i, 1])
return ret
def _measChromaticity(**kwargs):
"""Measure the chromaticity
Parameters
-----------
dfmax - max RF frequency change (within plus/minus), 1e-6
gamma - beam, 3.0/0.511e-3
alphac - momentum compaction factor, 3.62619e-4
wait - 1.5 second
num_points - 5
returns dp/p, nu, chrom
dpp - dp/p energy deviation
nu - tunes
chrom - result chromaticities
obt - orbit at each f settings (initial, every df, final).
"""
dfmax = kwargs.get("dfmax", 1e-6)
gamma = kwargs.get("gamma", 3.0e3 / .511)
alphac = kwargs.get("alphac", 3.6261976841792413e-04)
wait = kwargs.get("wait", 1.5)
npt = kwargs.get("num_points", 5)
verbose = kwargs.get("verbose", 0)
eta = alphac - 1 / gamma / gamma
obt = []
f0 = getRfFrequency(handle="setpoint")
nu0 = getTunes()
obt.append(getOrbit(spos=True))
_logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))
# incase RF does not allow large step change, ramp down first
if verbose:
print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(
f0, -dfmax, npt))
for df in np.linspace(0, abs(dfmax), npt)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / npt)
f = np.linspace(f0 - dfmax, f0 + dfmax, npt)
nu = np.zeros((len(f), 2), 'd')
for i, f1 in enumerate(f):
if verbose > 0:
print("freq= ", f1, end=" ")
putRfFrequency(f1)
time.sleep(wait)
nu[i, :] = getTunes()
obt.append(getOrbit(spos=True))
if verbose > 0:
print("tunes:", nu[i, 0], nu[i, 1], np.min(obt[-1][:, 0]),
np.max(obt[-1][:, 0]), np.min(obt[-1][:, 1]),
np.max(obt[-1][:, 1]))
for df in np.linspace(0, abs(dfmax), npt):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / npt)
obt.append(getOrbit(spos=True))
df = f - f0
dnu = nu - np.array(nu0)
p, resi, rank, sing, rcond = np.polyfit(df, dnu, deg=2, full=True)
chrom = p[-2, :] * (-f0 * eta)
if verbose > 0:
print("Coef:", p)
print("Resi:", resi)
print("Chrom:", chrom)
return df / (-f0 * eta), nu, chrom, obt
def measChromaticity(dfmax=1e-6,
gamma=3.0e3 / 0.511,
alphac=3.626e-4,
num_points=5,
fMeasTunes=None,
deg=2,
wait=0.5,
verbose=0):
"""Measure the chromaticity
Parameters
-----------
dfmax - max RF frequency change (within plus/minus), 1e-6
gamma - beam, 3.0/0.511e-3
alphac - momentum compaction factor, 3.62619e-4
wait - 1.5 second
num_points - 5
fMeasTunes - function used to get tunes. default None, use getTunes().
returns
--------
chrom : chromaticity, (chx, chy)
info : dictionary
freq : list of frequency setting
freq0 : initial frequency setpoint
tune : list of tunes, shape (num_points, 2)
dpp : dp/p energy deviation
obt : orbit at each f settings (initial, every df, final).
deg : degree of polynomial fitting.
p : polynomial coeff, shape (deg+1, 2)
"""
obt = []
f0 = getRfFrequency(handle="setpoint")
#names, x0, y0, Isum0, timestamp, offset = \
# measKickedTbtData(7, (0.15, 0.2), sleep=10, output=False)
#nu0 = (calcFftTunes(x0), calcFftTunes(y0))
nu0 = fMeasTunes() if fMeasTunes else getTunes()
obt.append(getOrbit(spos=True))
#_logger.info("Initial RF freq= {0}, tunes= {1}" % (f0, nu0))
# incase RF does not allow large step change, ramp down first
if verbose:
print("Initial RF freq= {0}, stepping down {1} in {2} steps".format(
f0, -dfmax, num_points))
for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / num_points)
f = np.linspace(f0 - dfmax, f0 + dfmax, num_points)
nu = np.zeros((len(f), 2), 'd')
for i, f1 in enumerate(f):
if verbose > 0:
print("dfreq= {0: .2e}".format(f1 - f0), end=" ")
putRfFrequency(f1)
time.sleep(wait)
nu[i, :] = fMeasTunes() if fMeasTunes else getTunes()
obt.append(getOrbit(spos=True))
if verbose > 0:
print(
"tunes: {0:.5f} {1:.5f}".format(nu[i, 0], nu[i, 1]),
"orbit min-max: {0:.2e} {1:.2e}, {2:.2e} {3:.2e}".format(
np.min(obt[-1][:, 0]), np.max(obt[-1][:, 0]),
np.min(obt[-1][:, 1]), np.max(obt[-1][:, 1])))
for df in np.linspace(0, abs(dfmax), num_points):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / num_points)
obt.append(getOrbit(spos=True))
# calculate chrom, return info
info = {"freq": f, "tune": nu, "orbit": obt, "freq0": f0, "deg": deg}
chrom, dpp, p = calcChromaticity(f0, f, nu, deg=deg)
info["dpp"] = dpp
info["p"] = p
return chrom, info
def measDispersion(elem,
dfmax=5e-7,
alphac=3.6261976841792413e-04,
gamma=5.870841487279844e3,
num_points=5,
full=False,
verbose=0):
"""measure dispersion at BPMs
Parameters
-----------
elem : BPM name, list or pattern
dfmax : float. frequency change (check the unit)
alphac : float. momentum compaction factor.
gamma : float. beam energy.
num_points : int. points to fit line
full : reserved.
Returns
--------
eta : numpy.array. (nelem, 3) with columns etax, etay and s
Examples
---------
>>> eta = measDispersion('p*c0[1-4]*')
"""
eta = alphac - 1.0 / gamma / gamma
bpmobj = [b for b in getElements(elem) if b.family == 'BPM']
bpmnames = [b.name for b in bpmobj]
nbpm = len(bpmnames)
_logger.info("measure dispersions at %d elements '%s'" %
(len(bpmnames), str(elem)))
f0 = getRfFrequency(handle="setpoint")
dflst = np.linspace(-abs(dfmax), abs(dfmax), num_points)
# incase RF does not allow large step change, ramp down first
for df in np.linspace(0, abs(dfmax), num_points)[1:-1]:
putRfFrequency(f0 - df)
time.sleep(2.0 / num_points)
# avoid a bug in virtac
obt0 = getOrbit(bpmnames)
cod = np.zeros((len(dflst), 2 * nbpm), 'd')
for i, df in enumerate(dflst):
v0 = getOrbit()
putRfFrequency(f0 + df)
if verbose > 0:
print(i, "df=", df, " f=", f0)
waitStableOrbit(v0)
# repeat the put/get in case simulator did not response latest results
obt = getOrbit(bpmnames)
#print i, obt[0,:2], obt0[0,:2], np.shape(obt), np.shape(obt0)
cod[i, :nbpm] = obt[:, 0] - obt0[:, 0]
cod[i, nbpm:] = obt[:, 1] - obt0[:, 1]
# restore
for df in np.linspace(0, abs(dfmax), num_points):
putRfFrequency(f0 + abs(dfmax) - df)
time.sleep(2.0 / num_points)
# fitting
p = np.polyfit(dflst, cod, deg=1)
disp = -p[0, :] * f0 * eta
s = np.array([e.sb for e in bpmobj], 'd')
ret = np.zeros((len(bpmobj), 3), 'd')
ret[:, 0] = disp[:nbpm]
ret[:, 1] = disp[nbpm:]
ret[:, 2] = s
if verbose > 0:
for i, bpm in enumerate(bpmobj):
print(i, bpm.name, bpm.sb, ret[i, 0], ret[i, 1])
return ret
