Gaussian noise in matlab

what is meant by gaussian noise& how to write a pgm in matlab?

here is some details on the gaussian noise

Additive white Gaussian noise - Wikipedia, the free encyclopedia

also there is a function in matlab called awgn

you can use the help of matlab to get some details on it

or Add white Gaussian noise to signal - MATLAB

y = awgn(x,snr) adds white Gaussian noise to the vector signal x. The scalar snr specifies the signal-to-noise ratio in decibels. If x is complex, then awgn adds complex noise. This syntax assumes that the power of x is 0 dBW.

y = awgn(x,snr,sigpower) is the same as the syntax above, except that sigpower is the power of x in dBW.

y = awgn(x,snr,'measured') is the same as y = awgn(x,snr), except that awgn measures the power of x before adding noise.

y = awgn(x,snr,sigpower,state) is the same as y = awgn(x,snr,sigpower), except that awgn first resets the state of the normal random number generator randn to the integer state.

y = awgn(x,snr,'measured',state) is the same as y = awgn(x,snr,'measured'), except that awgn first resets the state of normal random number generator randn to the integer state.