4 charts seem to cover it. BUt only 2 will do for a minimal number?
Just like 2 charts will do to cover a sphere? Even though there are 6 all together.
Hey guys, does anyone uses or knows about a software package that allows me to do gradation charts? (a gradation chart is a simple graphic where the x-axis is in logarithmic scale and the y-axis is in natural scale)
I was wondering about this, I've never seen any general theorem. Obviously it takes more than one, but I would think that in general it can take quite a few, for I can't see how to cover a torus with only 2.
Is there any sort of general result on this?