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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def zscale(data,contrast,min=100,max=60000):
 	"""Scale the data cube into the range 0-255"""


	## pic 100 random elements along each dimension
	## use zscale (see the IRAF display man page or
	## http://iraf.net/article.php/20051205162333315


	import random
	x=[]
	for i in random.sample(xrange(data.shape[0]),50):
	    for j in random.sample(xrange(data.shape[1]),50):
	 	x.append(data[i,j])
	
	yl=numarray.sort(numarray.clip(x,min,max))
	n=len(yl)
        ym=sum(yl)/float(n)

        xl=numarray.array(range(n))
 	xm=sum(xl)/float(n)	


	ss_xx=sum((xl-xm)*(xl-xm))
	ss_yy=sum((yl-ym)*(yl-ym))
        ss_xy=sum((xl-xm)*(yl-ym))
	b=ss_xy/ss_xx
	a=ym-b*xm

	z1=yl[n/2] + (b/contrast)*(1-n/2)
	z2=yl[n/2] + (b/contrast)*(n-n/2)

	## Now put the data inbetween Z1 and Z2
	high=data-z1
	z2=z2-z1
	high=numarray.clip(high,0,z2)

	## and change that to 0-255
	high= 256-256*high/z2

	### send back the scalled data
	return high