I can probably construct a log trendline with an uptrend as long as it is up at all if I use another number base

But yeah the traditional log10 chart line which we were so proud of is now practically broken... I admit that.

There isn't a mathematical difference between bases, unless you use a complex one (in which negative values could be in theory selected, preserving an uptrend by flipping the graph). To understand this better, realize that bBut yeah the traditional log10 chart line which we were so proud of is now practically broken... I admit that.

^{mn}= (b

^{m})

^{n}.

http://en.wikipedia.org/wiki/Logarithmic_scale#Motivation

Here is the quote in question:

Quote

Due to the identity:

log

the logarithms of any given number a to two different bases (here b and c) differ only by the constant factor log

log

_{b}a = log_{c}a / log_{c}bthe logarithms of any given number a to two different bases (here b and c) differ only by the constant factor log

_{c}b.