fit24b.rb

require 'statsample'



def fit(l, y, lx)

	a = {}

	(lx + [y]).each { |x| a[x] = l.map { |b| b[x] }.to_vector() }

	ds = a.to_dataset()

	r = Statsample::Regression.multiple(ds, y)
	$stderr.puts(r.summary)

	return r.coeffs.merge({'c' => r.constant})

end

def predict(z, l1)
	l1.each \
	{
		|x|
		t = z['c']
		
		(z.keys - ['c']).each { |k| t += z[k] * x[k] }
		x['y_p'] = t
	}
end

def out(fn, l)
	
	f = File.open("#{fn}.txt", 'w')
	f.puts(l[0].keys.join("\t"))
	l.each { |x| f.puts(x.values.join("\t")) }
	f.close
	
end

def read(fn)
	
	l = File.open('data.txt').readlines
	l1 = l.shift.split
	return l.map \
	{
		|x|
		Hash[[l1, x.split.map { |y| y.to_f }].transpose]
	}
	
end


	
l2 = read('data.txt')

$stderr.puts("#{l2.size} pts")
# out('out', l2)

z = fit(l2, 'y', l2[0].keys - ['y'])

predict(z, l2)

out('out1', l2.sort_by { |x| x['y'] })