On 6/29/14, 8:50 AM, Iain Buclaw via Digitalmars-d wrote:
On 29 June 2014 15:59, Andrei Alexandrescu via Digitalmars-d
<[email protected]> wrote:
On 6/28/14, 9:36 PM, H. S. Teoh via Digitalmars-d wrote:
On Sat, Jun 28, 2014 at 05:16:53PM -0700, Walter Bright via Digitalmars-d
wrote:
On 6/28/2014 3:57 AM, Russel Winder via Digitalmars-d wrote:
[...]
Or indeed when calculating anything to do with money.
You're better off using 64 bit longs counting cents to represent money
than using floating point. But yeah, counting money has its own
special problems.
For counting money, I heard that the recommendation is to use
fixed-point arithmetic (i.e. integer values in cents).
A friend who works at a hedge fund (after making the rounds to the NYC large
financial companies) told me that's a myth. Any nontrivial calculation
involving money (interest, fixed income, derivatives, ...) needs floating
point. He never needed more than double.
Andrei
I would have thought money would use fixed point decimal floats.
And what meaningful computation can you do with such? Using fixed point
for money would be like the guy in Walter's story rounding to two
decimals after each step in the calculation.
Even for a matter as simple as average price for a share bought in
multiple batches you need floating point.
Andrei
