>"Mixed operations involving decimal and binary floating-point or integer types are supported (the result is promoted to decimal floating-point)."
>Is that really advised? I meant for binary only. Mixing with integer is ok. Another idea. Mixing ok, but promoting to binary. Subsequent calculations will not be slow :) Con, why start with decimal in the first place? Another idea, can convertions be disabled by default (get runtime errors/exceptions) and you could enable them if you want globally? Not sure if that works or has to do with macros.. Runtime penalty? -- Palli. On Thursday, April 30, 2015 at 11:56:28 PM UTC, Páll Haraldsson wrote: > > "In general, you should be able to use the DecFP types in any context > where you would have used binary floating-point types: arrays, complex > arithmetic, and linear algebra should all work, for the most part." > > Way better than what I was going for - I thought only +, -, *, / was > needed and maybe only wanted.. plus convert but not automatic: > > "Mixed operations involving decimal and binary floating-point or integer > types are supported (the result is promoted to decimal floating-point)." > > Is that really advised? Is that what you do or the C library? In C you > have automatic promotion between native types, but I guess you can't > otherwise. The library you wrap provides converts (good), you make them > automatic (bad?). > > At first blush, as Julia is generic by default, this seems what you would > want, but is it? When I thought about this, it seemed just dangerous. If > you force people to use manual conversion you might get away with wrapping > fewer functions? > > "Most basic arithmetic functions are supported, and many special functions > (sqrt, log, trigonometric functions, etc.)." > > I'm not sure if the library you wrap provides this and if it does, doesn't > convert to binary floating point, runs the function, then converts back? > Whether it does it or you do it, is it not better to let the user decide on > both converts? And faster if you eliminate some.. > > I just scanned the code or one file: > > for c in (:π, :e, :γ, :catalan, :φ) > > Not sure if these are the only Julia constants.. Or only you care about. > Anyway, wasn't expecting to see them in any decimal context. I would not be > rich with π dollars in my account. :) > > -- > Palli. > > On Wednesday, April 29, 2015 at 1:26:17 AM UTC, Steven G. Johnson wrote: >> >> The DecFP package >> >> https://github.com/stevengj/DecFP.jl >> >> provides 32-bit, 64-bit, and 128-bit binary-encoded decimal >> floating-point types following the IEEE 754-2008, implemented as a wrapper >> around the (BSD-licensed) Intel Decimal Floating-Point Math Library >> <https://software.intel.com/en-us/articles/intel-decimal-floating-point-math-library>. >> >> Decimal floating-point types are useful in situations where you need to >> exactly represent decimal values, typically human inputs. >> >> As software floating point, this is about 100x slower than hardware >> binary floating-point math. On the other hand, it is significantly >> (10-100x) faster than arbitrary-precision decimal arithmetic, and is a >> memory-efficient bitstype. >> >> The basic arithmetic functions, conversions from other numeric types, and >> numerous special functions are supported. >> >
