# mixed.py: generate mixed sets of test data
# Robyn A. McNamara  November 2002

from random import *

N = 4			# number of competencies
population = 400	# student population
K=3			# factors per question
students = []
questions = []

def vmult(v, w):
  if len(v) != len(w):
    print "Error: vectors of different lengths"
    print "v =", v,"; w =", w
    return
  
  p = 0.0		# accumulates vector product
  for i in range(len(v)):
    p = p + float(v[i]) * float(w[i])

  return p
  

# generate student vectors
for i in range(population):
	s = []
	for j in range(N):
		p = gauss(0.5, 0.25) + 0.25
		p = min(max(p,0),1)
		s.append(p)
	students.append(s)

# generate question vectors
for i in range(80):
	q = [0.0] * N
	for j in range(K):
		factor = randrange(N)
		q[factor] = q[factor] + 1.0
	for j in range(N):
		q[j] = q[j] / float(K)
	questions.append(q)

	


# work out student marks
for s in students:
	for q in questions:
		p = vmult(s, q)
		mark = 0
		for m in range(10):
			if random() > p:
				mark = mark + 1
		print "%d\t" % mark,
	print

print "=" * 75
for i in range(len(questions)):
	print "Q[%d] = " % i, questions[i]