I had reason to use complex numbers in Lua recently. I tried to save
time by using someone else's complex number package. You should
conclude from this note that public packages require careful scrutiny.
I found a post to this list that included Lua code for complex
numbers, but its definition of division has a sign error. I
downloaded the LuaMatrix 2.0.8 package, but its complex number code is
very difficult to read and I noticed an error in the definition for
the natural logarithm.
I visited my bookcase and found:
"Introduction to Complex Variables and Applications", Ruel
V. Churchill, McGraw-Hill Book Company, Inc, 1949.
Note the year. It's a wonderful book. I used it to guide the writing
of a complex number package. I don't have a good place to make it
available, so I've put it in the CVS repository for the lineqpp
project on LuaForge.
Let me conclude with a very serious question. Is there a vetting
process for Lua packages? For example, is there a way to gain
confidence in some package because several others assert it has done
right by them? Shouldn't there be a complex number package that is
the one the community agrees is solid?