def plotit(fobs,
sigma,
fcalc,
alpha,
beta,
epsilon,
centric,
out,
limit=5.0,
steps=1000,
plot_title="Outlier plot"):
fobs_a = flex.double( [fobs] )
fcalc_a = flex.double( [fcalc] )
epsilon_a = flex.double( [epsilon] )
alpha_a = flex.double( [alpha] )
beta_a = flex.double( [beta] )
centric_a = flex.bool ( [centric] )
p_calc = scaling.likelihood_ratio_outlier_test(
fobs_a,
None,
fcalc_a,
epsilon_a,
centric_a,
alpha_a,
beta_a)
print >> out
print >> out,"#Input parameters: "
print >> out,"#Title : ", plot_title
print >> out,"#F-calc : ", fcalc
print >> out,"#F-obs : ", fobs
print >> out,"#epsilon : ", epsilon
print >> out,"#alpha : ", alpha
print >> out,"#beta : ", beta
print >> out,"#centric : ", centric
mode = p_calc.posterior_mode()[0]
snd_der = math.sqrt(1.0/ math.fabs( p_calc.posterior_mode_snd_der()[0] ) )
print >> out,"#A Gaussian approximation of the likelihood function"
print >> out,"#could be constructed as follows with: "
print >> out,"# exp[-(fobs-mode)**2/(2*stdev**2)] /(sqrt(2 pi) stdev)"
print >> out,"#with"
print >> out,"#mode = ", mode
print >> out,"#stdev = ", snd_der
print >> out
print >> out,"#The log likelihood values for the mode and "
print >> out,"#observed values are"
print >> out,"#Log[P(fobs)] : ", p_calc.log_likelihood()[0]
print >> out,"#Log[P(mode)] : ", p_calc.posterior_mode_log_likelihood()[0]
print >> out,"#Their difference is:"
print >> out,"#delta : ", p_calc.log_likelihood()[0]-p_calc.posterior_mode_log_likelihood()[0]
print >> out,"#"
mean_fobs = p_calc.mean_fobs()
print >> out,"#mean f_obs : ", mean_fobs[0], " (first moment)"
low_limit = mode-snd_der*limit
if low_limit<0:
low_limit=0
high_limit = mode+limit*snd_der
if fobs < low_limit:
low_limit = fobs-2.0*snd_der
if low_limit<0:
low_limit=0
if fobs > high_limit:
high_limit = fobs+2.0*snd_der
fobs_a = flex.double( range(steps) )*(
high_limit-low_limit)/float(steps)+low_limit
fcalc_a = flex.double( [fcalc]*steps )
epsilon_a = flex.double( [epsilon]*steps )
alpha_a = flex.double( [alpha]*steps )
beta_a = flex.double( [beta]*steps )
centric_a = flex.bool ( [centric]*steps )
p_calc = scaling.likelihood_ratio_outlier_test(
fobs_a,
None,
fcalc_a,
epsilon_a,
centric_a,
alpha_a,
beta_a)
ll = p_calc.log_likelihood() #-p_calc.posterior_mode_log_likelihood()
ll = flex.exp( ll )
if (sigma is None) or (sigma <=0 ):
sigma=fobs/30.0
obs_gauss = (fobs_a - fobs)/float(sigma)
obs_gauss = flex.exp( -obs_gauss*obs_gauss/2.0 ) /(
math.sqrt(2.0*math.pi*sigma*sigma))
max_ll = flex.max( ll )*1.10
truncate_mask = flex.bool( obs_gauss >= max_ll )
obs_gauss = obs_gauss.set_selected( truncate_mask, max_ll )
ccp4_loggraph_plot = data_plots.plot_data(
plot_title=plot_title,
x_label = 'Fobs',
y_label = 'P(Fobs)',
x_data = fobs_a,
y_data = ll,
y_legend = 'P(Fobs|Fcalc,alpha,beta)',
comments = 'Fobs=%5.2f, sigma=%5.2f, Fcalc=%5.2f'%(fobs,sigma,fcalc) )
ccp4_loggraph_plot.add_data(
y_data = obs_gauss,
y_legend = "P(Fobs|<Fobs>,sigma)"
)
data_plots.plot_data_loggraph(ccp4_loggraph_plot,out)
def example():
x_obs = (flex.double(range(100)) + 1.0) / 101.0
y_ideal = flex.sin(x_obs * 6.0 * 3.1415) + flex.exp(x_obs)
y_obs = y_ideal + (flex.random_double(size=x_obs.size()) - 0.5) * 0.5
w_obs = flex.double(x_obs.size(), 1)
print "Trying to determine the best number of terms "
print " via cross validation techniques"
print
n_terms = chebyshev_lsq_fit.cross_validate_to_determine_number_of_terms(
x_obs, y_obs, w_obs, min_terms=5, max_terms=20, n_goes=20, n_free=20)
print "Fitting with", n_terms, "terms"
print
fit = chebyshev_lsq_fit.chebyshev_lsq_fit(n_terms, x_obs, y_obs)
print "Least Squares residual: %7.6f" % (fit.f)
print " R2-value : %7.6f" % (fit.f / flex.sum(y_obs * y_obs))
print
fit_funct = chebyshev_polynome(n_terms, fit.low_limit, fit.high_limit,
fit.coefs)
y_fitted = fit_funct.f(x_obs)
abs_deviation = flex.max(flex.abs((y_ideal - y_fitted)))
print "Maximum deviation between fitted and error free data:"
print " %4.3f" % (abs_deviation)
abs_deviation = flex.mean(flex.abs((y_ideal - y_fitted)))
print "Mean deviation between fitted and error free data:"
print " %4.3f" % (abs_deviation)
print
abs_deviation = flex.max(flex.abs((y_obs - y_fitted)))
print "Maximum deviation between fitted and observed data:"
print " %4.3f" % (abs_deviation)
abs_deviation = flex.mean(flex.abs((y_obs - y_fitted)))
print "Mean deviation between fitted and observed data:"
print " %4.3f" % (abs_deviation)
print
print "Showing 10 points"
print " x y_obs y_ideal y_fit"
for ii in range(10):
print "%6.3f %6.3f %6.3f %6.3f" \
%(x_obs[ii*9], y_obs[ii*9], y_ideal[ii*9], y_fitted[ii*9])
try:
from iotbx import data_plots
except ImportError:
pass
else:
print "Preparing output for loggraph in a file called"
print " chebyshev.loggraph"
chebyshev_plot = data_plots.plot_data(plot_title='Chebyshev fitting',
x_label='x values',
y_label='y values',
x_data=x_obs,
y_data=y_obs,
y_legend='Observed y values',
comments='Chebyshev fit')
chebyshev_plot.add_data(y_data=y_ideal, y_legend='Error free y values')
chebyshev_plot.add_data(y_data=y_fitted,
y_legend='Fitted chebyshev approximation')
output_logfile = open('chebyshev.loggraph', 'w')
f = StringIO()
data_plots.plot_data_loggraph(chebyshev_plot, f)
output_logfile.write(f.getvalue())
def example():
x_obs = (flex.double(range(100))+1.0)/101.0
y_ideal = flex.sin(x_obs*6.0*3.1415) + flex.exp(x_obs)
y_obs = y_ideal + (flex.random_double(size=x_obs.size())-0.5)*0.5
w_obs = flex.double(x_obs.size(),1)
print "Trying to determine the best number of terms "
print " via cross validation techniques"
print
n_terms = chebyshev_lsq_fit.cross_validate_to_determine_number_of_terms(
x_obs,y_obs,w_obs,
min_terms=5 ,max_terms=20,
n_goes=20,n_free=20)
print "Fitting with", n_terms, "terms"
print
fit = chebyshev_lsq_fit.chebyshev_lsq_fit(n_terms,x_obs,y_obs)
print "Least Squares residual: %7.6f" %(fit.f)
print " R2-value : %7.6f" %(fit.f/flex.sum(y_obs*y_obs))
print
fit_funct = chebyshev_polynome(
n_terms, fit.low_limit, fit.high_limit, fit.coefs)
y_fitted = fit_funct.f(x_obs)
abs_deviation = flex.max(
flex.abs( (y_ideal- y_fitted) ) )
print "Maximum deviation between fitted and error free data:"
print " %4.3f" %(abs_deviation)
abs_deviation = flex.mean(
flex.abs( (y_ideal- y_fitted) ) )
print "Mean deviation between fitted and error free data:"
print " %4.3f" %(abs_deviation)
print
abs_deviation = flex.max(
flex.abs( (y_obs- y_fitted) ) )
print "Maximum deviation between fitted and observed data:"
print " %4.3f" %(abs_deviation)
abs_deviation = flex.mean(
flex.abs( (y_obs- y_fitted) ) )
print "Mean deviation between fitted and observed data:"
print " %4.3f" %(abs_deviation)
print
print "Showing 10 points"
print " x y_obs y_ideal y_fit"
for ii in range(10):
print "%6.3f %6.3f %6.3f %6.3f" \
%(x_obs[ii*9], y_obs[ii*9], y_ideal[ii*9], y_fitted[ii*9])
try:
from iotbx import data_plots
except ImportError:
pass
else:
print "Preparing output for loggraph in a file called"
print " chebyshev.loggraph"
chebyshev_plot = data_plots.plot_data(plot_title='Chebyshev fitting',
x_label = 'x values',
y_label = 'y values',
x_data = x_obs,
y_data = y_obs,
y_legend = 'Observed y values',
comments = 'Chebyshev fit')
chebyshev_plot.add_data(y_data=y_ideal,
y_legend='Error free y values')
chebyshev_plot.add_data(y_data=y_fitted,
y_legend='Fitted chebyshev approximation')
output_logfile=open('chebyshev.loggraph','w')
f = StringIO()
data_plots.plot_data_loggraph(chebyshev_plot,f)
output_logfile.write(f.getvalue())
