Re: How to increase Working Precision?

marks@xxxxxxxxxxx wrote:

x has a small relative error (high precision)

In[1]:= x = 3.15000000000000000000000000000000;

In[2]:= Precision[x]

Out[2]= 32.4983

Sorry, but the standard notion of “relative error” is always “relative
to the exact result approximated.” As an approximation to pi, x has a
relative error of 0.0027, which is not all that small. The relative
error of a number does not change in the least when you add more zeroes
at the end, after the decimal point. Actually, in standard notation,
3.15000000000000000000000000000000 is exactly the same number as 3.15.
At least in pure math. A subset of engineers disagrees, of course, as do
most programs having multi-precision floats, and for good reason.

--
if all this stuff was simple, we'd
probably be doing something else. -- Daniel Lichtblau, s.m.symbolic
.

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