ARROWS: generalized and vectorized 2-D arrows plot

This little function is an alternative to other existing arrow plot functions, since it has very simple, vectorized and effective coding. In fact, arrows are all plotted with a single patch command! The function also accepts any standard patch parameter/value pair like 'FaceColor', 'EdgeColor', 'LineWidth', etc.

It can be used to plot a personalized arrow at coordinates X,Y with length L and azimuth AZ, or any of these arguments can be vector or matrix, like QUIVER did, to plot multiple arrows. The option 'Cartesian' allows defining U and V components instead of polar L and AZ.

Arrow's aspect ratio, head and segment line shapes are configurable with 4 parameters: head width, head length, head inside length and segment line width, all normalized to arrow's length. See the upper part of examples figure.

It is also possible to vary only the arrow length with fixed head and line width, using a reference length. The examples figure shows the effect of this option: upper arrows use a reference length, while lower arrows do not.