#-------------------------------------------------------------------------------------------
# Import prostredia pre pracu s kniznicami numpy, scipy, matplotlib....


% pylab inline 
import urllib2

#---------------------------------------------------------------------------------
# Funkcia pre vytvorenie matice dat - vstup: string s linkom pre konkretne data z databazy tokamaku GOLEM

def data_array(data):
    datas = urllib2.urlopen(data)
    lines = datas.readlines()
    for k,l in enumerate(lines):
        lines[k] = l.strip().split()
        for i,j in enumerate(lines[k]):
            try: 
                lines[k][i] = float(j)
            except 'ValueError':
                print('not a number')
    return array(lines)

#----------------------------------------------------------------------------------
#  Data  pre prud v plazme a a urcenie casu pre zaciatok vyboja

shot = # shot number#

I_plasma = data_array('http://golem.fjfi.cvut.cz/utils/data/%i/plasma_current'%shot)
shot_start = data_array('http://golem.fjfi.cvut.cz/utils/data/%i/plasma_start'%shot)

#----------------------------------------------------------------------------------
# Definovana fitovacia funkcia pre start up fazu

def f(t,t_0,L,n0,t0):
    ft = zeros_like(t)
    for i, j in enumerate(t):
        if j <=t_0:
            ft[i] = n0*exp((1/L)*(j-t0))
        elif j > t_0:
            ft[i] = (n0/L)*exp(((t_0-t0)/L))*(j) + (1-(t_0/L))*(n0)*exp(((t_0-t0)/L))
    return ft

#---------------------------------------------------------------------------------
# Urcenie rozpatia dat pre fitovanie 

zac = 500
kon = 300
def time_interval(start,I_p):
    beg = argmin(abs(I_p[:,0] - start)) - zac
    end = argmin(abs(I_p[:,0] - start)) + kon
    return array([beg,end])

beg = time_interval(shot_start,I_plasma)[0]
end = time_interval(shot_start,I_plasma)[1]

#-------------------------------------------------------------------------------
# Vypocet parametrov definujucich start up fazu vyboja

p0 = array([0.0123,   5.24058646e-05,   8.74081919e+01,0.0124])
param, c = curve_fit(f,I_plasma[beg:end,0],I_plasma[beg:end,1]-mean(I_plasma[beg:end-300,1]),p0)