import numpy as np
import pylab

def interplin2p(x,xi,yi,xi1,yi1):
    return yi+(yi1-yi)*(x-xi)/(xi1-xi)

def interplinvect(x,xyvect):
    xinterp=[]
    yinterp=[]
    for xk in x:
        N=len(xyvect[0])
        for i in range(0,N-1):
            if(xk>=xyvect[0][i] and xk<xyvect[0][i+1]):
                xinterp.append(xk)
                yinterp.append(interplin2p(xk,xyvect[0][i],xyvect[1][i],xyvect[0][i+1],xyvect[1][i+1]))
            i=i+1
    return(xinterp,yinterp)

xyv=[]
xyv.append([i for i in np.arange(0.1,3.3,0.1)])
xyv.append([np.cos(1/i) for i in np.arange(0.1,3.3,0.1)])
print(xyv)
print(len(xyv[0]))
pylab.plot (xyv[0], xyv[1], '.',xyv[0], xyv[1],'-')
pylab.show()

xin=[i for i in np.arange(0,3.3,0.08)]
xyinterp = interplinvect(xin,xyv)
print(xyinterp)
pylab.plot(xyinterp[0], xyinterp[1], '-',xyv[0], xyv[1], '^r')
pylab.show()

print(len(xyinterp[0]))
print(len(xyinterp[1]))
print(len(xin))


del xyv[:]
xyv.append([i for i in np.arange(0.1,3.3,0.1)])
xyv.append([np.exp(np.sin(i)) for i in np.arange(0.1,3.3,0.1)])
print(xyv)
print(len(xyv[0]))
pylab.plot (xyv[0], xyv[1], '.',xyv[0], xyv[1],'-')
pylab.show()

xin=[i for i in np.arange(0.1,3.3,0.08)]
xyinterp = interplinvect(xin,xyv)
print(xyinterp)
pylab.plot(xyinterp[0], xyinterp[1], '-',xyv[0], xyv[1], '^r')
pylab.show()

print(len(xyinterp[0]))
print(len(xyinterp[1]))
print(len(xin))