Adding Signals

Modules:

add_cc()
add_ff()
add_ii()
add_ss()

for complex, float, integer and short.

Example usage:

	adder19 = add_ff()

instantiates a floating point adder.

Example:

	sampling_freq = 8e6
	fg = gr.flow_graph ()

	src0 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 1e6, 1, 0)
	src1 = gr.sig_source_f (sampling_freq, gr.GR_SIN_WAVE, 800e3, .9, 0)
	
	adder = gr.add_ff ()

	dst = gr.file_sink (gr.sizeof_float, "test_output")

	fg.connect ( src0, (adder, 0) )
	fg.connect ( src1, (adder, 1) )
	fg.connect ( adder, dst )
This creates two signals at 8Mhz sampling rate, one is 1Mhz and the other
is 800Khz, then adds the two and writes the result to a file called
"test_output". Note the use of two different ports, 0 and 1 for the adder
inputs. The resultant signal is: