SCALARS

		n,m,N 		number of components in a vector
		x,y,z 		Cartesian coordinates
		r 		radius
		$\phi$ 		phase angle
		$z=x+iy=re^{i\phi}$ 		complex number
		$\overline{z}$		complex conjugate of z 
		t 		time; transmission coefficient
		j,k 		index on discrete time
		f 		generic function; frequency in cycles
		$\omega =2\pi f$ 		angular frequency (common)
		$Z=e^{i\omega \Delta t}$ Z-transform variable
		$\ast$ 		convolution; multiplication (in programs)
		$\Delta t, dt$ 		sampling time interval
		$\Delta f, df$ 		frequency sampling interval
		$\Delta T$ 		extent of time axis
		$\Delta F$ 		extent of frequency axis
		$\Lambda T$ 		signal duration
		$\Lambda F$ 		spectral bandwidth
		$\sigma^2$ 		variance
		c 		reflection coefficient