Gaussian line shape.

yabs = gaussian(x,x0,fwhm)
yabs = gaussian(x,x0,fwhm,diff)
yabs = gaussian(x,x0,fwhm,diff,phase)
[yabs,ydisp] = ...

This function returns a Gaussian line shape with center x0 and full width at half height fwhm over the abscissa values defined in the vector x.

diff determines the derivative to compute. 0 stands for no derivative, 1 is the first one, 2 the second one, -1 indicates the integral with as lower limit. If diff is not given, it is set to 0 by default.

yabs is the absorption Gaussian line shape, and ydisp is the dispersion Gaussian line shape.

If phase is given, the absorption and dispersion line shapes are both rotated the by the given amount (in radians). E.g., with phase=pi/2, yabs would contain the dispersion line shape.

x = linspace(-100,100,1e3); x0 = 34; w = 20;
y = gaussian(x,x0,w);
plot(x,y);

sum(y)*(x(2)-x(1))

ans =
    1.0000

x = linspace(-100,100,1e3); x0 = 14; w = 20;
[ya,yd] = gaussian(x,x0,w);
plot(x,ya,x,yd);