Windowing functions are explained on Wikipedia and they include plots of the Fourier transform for several windowing functions. For the triangle window they provide
The above Fourier transform plot has a horizontal axis that goes from -40 bins to +40 bins, so this seems to be a discrete Fourier transform. However, I don't get a plot like that when I apply an FFT to 80 samples of a triangular window. I am further confused in that the graphic of the Fourier transform looks like a continuous plot rather than 80 discrete samples.
My questions are: How does one create the plot for the Fourier transform of a triangular window? Is the plot for a continuous Fourier transform or discrete Fourier transform?