******************************************
Feed Forward Multilayer Perceptron (newff)
******************************************

Use  :py:func:`neurolab.net.newff`

::

	import neurolab as nl
	import numpy as np

	# Approximation function: 1/2 * sin(x)
	x = np.linspace(-7, 7, 20)
	y = np.sin(x) * 0.5

	size = len(x)

	inp = x.reshape(size,1)
	tar = y.reshape(size,1)

	# Create network with 2 layers and rendom initialized
	net = nl.net.newff([[-10, 10]],[5, 1])

	# Train network
	error = net.train(inp, tar, epochs=500, show=100, goal=0.02)

	# Simulate network
	out = net.sim(inp)

	# Plot result
	import pylab as pl
	pl.subplot(211)
	pl.plot(error)
	pl.xlabel('Epoch number')
	pl.ylabel('error (default SSE)')

	x2 = np.linspace(-6.0,6.0,150)
	y2 = net.sim(x2.reshape(x2.size,1)).reshape(x2.size)

	y3 = out.reshape(size)

	pl.subplot(212)
	pl.plot(x2, y2, '-',x , y, '.', x, y3, 'p')
	pl.legend(['train target', 'net output'])
	pl.show()

:Result:
	.. image:: _static/ff_sin.png