import numpy as np
from matplotlib import pylab as plt

def readTraceTextfile(fina,numbers=None):
    if not numbers is None:
        d = [readTraceTextfile(fina%number) for number in numbers]
    else:
        d  = np.loadtxt(fina, skiprows=5, delimiter=',')
    return d

def getRiseTime(t,s,lims=[.1,.9]):
    lims = np.asarray(lims)
    t = np.asarray(t)
    s = np.asarray(s)
    sel = t>0
    mxind = np.min((np.diff(s[sel])<0).nonzero()[0])
    mxind = sel.nonzero()[0][mxind]
    sel = t<=0
    mnind = np.max((np.diff(s[sel])<0).nonzero()[0])
    mnind = sel.nonzero()[0][mnind]+1
    crosspty = lims*(s[mxind]-s[mnind])+s[mnind]
    crossptx = np.interp(crosspty, s[mnind:mxind+1],t[mnind:mxind+1])
    return float(np.round(np.diff(crossptx),decimals=13)),[crossptx,crosspty]

def plotTrace(fina='./scope2_testdata_2017-02-21/C2Trace00003txt'):
    t,s = readTraceTextfile(fina).T
    rt,crossers = getRiseTime(t,s)
    ax = plt.gca()
    ax.plot(t,s,'.-',label='rise time = %3g (fwhm)'%rt)
    ax.plot(crossers[0],crossers[1],'xr')
    ax.set_xlabel('Time / s')
    ax.set_ylabel('Amplitude / V')