source: sasview/pr_inversion/num_term.py @ 14226f4

import unittest, math, numpy, pylab, sys, string
from sans.pr.invertor import Invertor

class Num_terms():    
    
     def __init__(self, invertor):
         self.invertor = invertor
         self.nterm_min = 10
         self.nterm_max = len(self.invertor.x)
         self.isquit_func = None
         
         self.osc_list = []
         self.err_list = []
         self.alpha_list = []
         self.mess_list = []
         
         self.dataset = []
     
     def is_odd(self, n):
         return bool(n%2)

     def sort_osc(self):
         import copy
         osc = copy.deepcopy(self.dataset)
         lis = []
         for i in range(len(osc)):
             osc.sort()
             re = osc.pop(0)
             lis.append(re)
         return lis
           
     def median_osc(self):
         osc = self.sort_osc()
         dv = len(osc)
         med = float(dv) / 2.0
         odd = self.is_odd(dv)
         medi = 0
         for i in range(dv):
             if odd == True:
                 medi = osc[int(med)]
             else:
                 medi = osc[int(med) - 1]
         return medi

     def get0_out(self):
        inver = self.invertor
        self.osc_list = []
        self.err_list = []
        self.alpha_list = []
        for k in range(self.nterm_min, self.nterm_max):
            if self.isquit_func != None:
                self.isquit_func()
            best_alpha, message, elapsed = inver.estimate_alpha(k)
            inver.alpha = best_alpha
            inver.out, inver.cov = inver.lstsq(k)
            osc = inver.oscillations(inver.out)
            err = inver.get_pos_err(inver.out, inver.cov)
            
            self.osc_list.append(osc)
            self.err_list.append(err)
            self.alpha_list.append(inver.alpha)
            self.mess_list.append(message)
         
        #print "osc", self.osc_list
        #print "err", self.err_list
        #print "alpha", self.alpha_list
        new_ls = []
        new_osc1 = []
        new_osc2= []
        new_osc3 = []
        flag9=False
        flag8=False
        flag7=False
        for i in range(len(self.err_list)):
            if self.err_list[i] <= 1.0 and self.err_list[i] >=0.9:
                new_osc1.append(self.osc_list[i])
                flag9=True
            if self.err_list[i] < 0.9 and self.err_list[i] >=0.8:
                new_osc2.append(self.osc_list[i])
                flag8=True
            if self.err_list[i] <0.8 and self.err_list[i] >= 0.7:
                new_osc3.append(self.osc_list[i])
                falg7=True
                 
        if flag9==True:
            self.dataset = new_osc1
        elif flag8==True:
            self.dataset = new_osc2
        else:
            self.dataset = new_osc3
         
        #print "dataset", self.dataset
        return self.dataset
        
     def ls_osc(self):
        # Generate data
        ls_osc = self.get0_out()
        med = self.median_osc()
        
        #TODO: check 1
        ls_osc = self.dataset
        ls = []
        for i in range(len(ls_osc)):
            if int(med) == int(ls_osc[i]):
                ls.append(ls_osc[i])
        return ls

     def compare_err(self):
        ls = self.ls_osc()
        #print "ls", ls
        nt_ls = []
        for i in range(len(ls)):
            r = ls[i]
            n = self.osc_list.index(r) + 10
            #er = self.err_list[n]
            #nt = self.osc_list.index(r) + 10
            nt_ls.append(n)
        #print "nt list", nt_ls
        return nt_ls

     def num_terms(self, isquit_func=None):
         try:
             self.isquit_func = isquit_func
             #self.nterm_max = len(self.invertor.x)
             #self.nterm_max = 32
             nts = self.compare_err()
             #print "nts", nts
             div = len(nts)
             tem = float(div)/2.0
             odd = self.is_odd(div)
             if odd == True:
                 nt = nts[int(tem)]
             else:
                 nt = nts[int(tem) - 1]
             return nt, self.alpha_list[nt - 10], self.mess_list[nt-10]
         except:
             return self.nterm_min, self.alpha_list[10], self.mess_list[10]

#For testing
def load(path):
        import numpy, math, sys
        # Read the data from the data file
        data_x   = numpy.zeros(0)
        data_y   = numpy.zeros(0)
        data_err = numpy.zeros(0)
        scale    = None
        min_err  = 0.0
        if not path == None:
            input_f = open(path,'r')
            buff    = input_f.read()
            lines   = buff.split('\n')
            for line in lines:
                try:
                    toks = line.split()
                    x = float(toks[0])
                    y = float(toks[1])
                    if len(toks)>2:
                        err = float(toks[2])
                    else:
                        if scale==None:
                            scale = 0.05*math.sqrt(y)
                            #scale = 0.05/math.sqrt(y)
                            min_err = 0.01*y
                        err = scale*math.sqrt(y)+min_err
                        #err = 0
                        
                    data_x = numpy.append(data_x, x)
                    data_y = numpy.append(data_y, y)
                    data_err = numpy.append(data_err, err)
                except:
                    pass
                   
        return data_x, data_y, data_err
    

if __name__ == "__main__":
    i = Invertor()
    x, y, erro = load("test/Cyl_A_D102.txt")
    i.d_max = 102.0
    i.nfunc = 10    
    #i.q_max = 0.4
    #i.q_min = 0.07
    i.x   = x
    i.y   = y
    i.err = erro   
    #i.out, i.cov = i.lstsq(10)
    # Testing estimator
    est = Num_terms(i)
    print est.num_terms()