Re: [go-nuts] Working with Floating-Point numbers
Do you have particular questions? The overall situation is that floating point arithmetic is good, but not like real numbers or symbolic algebra; it is its own world and respecting the details is important (NaNs, representability, tolerance in comparison, etc.) On Mon, Feb 12, 2018 at 10:24 AM, Ian Lance Taylor wrote: > On Mon, Feb 12, 2018 at 9:40 AM, go-question > wrote: > > > > When working with Floating-point values in Go, what considerations need > to > > be made? > > > > The same for any other language? > > > > The Spec says that "Floating-point values are comparable and ordered" > > https://golang.org/ref/spec#Comparison_operators > > > > So is comparing by some epsilon value not needed? or only for computed > > values? > > http://www.cygnus-software.com/papers/comparingfloats/ > Comparing%20floating%20point%20numbers.htm > > > > What is recommended (without external packages) when multiplying or > adding > > Floating-point values? > > I know that internally those operations can be imprecise. > > https://github.com/shopspring/decimal#faq > > http://floating-point-gui.de/basic/ > > This classic paper applies to Go just as much as it does to other > programming languages: > > https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html > > Ian > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Michael T. Jones michael.jo...@gmail.com -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [go-nuts] Working with Floating-Point numbers
On Mon, Feb 12, 2018 at 9:40 AM, go-question wrote: > > When working with Floating-point values in Go, what considerations need to > be made? > > The same for any other language? > > The Spec says that "Floating-point values are comparable and ordered" > https://golang.org/ref/spec#Comparison_operators > > So is comparing by some epsilon value not needed? or only for computed > values? > http://www.cygnus-software.com/papers/comparingfloats/Comparing%20floating%20point%20numbers.htm > > What is recommended (without external packages) when multiplying or adding > Floating-point values? > I know that internally those operations can be imprecise. > https://github.com/shopspring/decimal#faq > http://floating-point-gui.de/basic/ This classic paper applies to Go just as much as it does to other programming languages: https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [go-nuts] Working with Floating-Point numbers
I would say it's the same as most languages. Go implements IEEE floating point, so any comparison with a NaN is false. On Mon, Feb 12, 2018 at 12:40 PM, go-question wrote: > When working with Floating-point values in Go, what considerations need to > be made? > > The same for any other language? > > The Spec says that "Floating-point values are comparable and ordered" > https://golang.org/ref/spec#Comparison_operators > > So is comparing by some epsilon value not needed? or only for computed > values? > http://www.cygnus-software.com/papers/comparingfloats/ > Comparing%20floating%20point%20numbers.htm > > What is recommended (without external packages) when multiplying or adding > Floating-point values? > I know that internally those operations can be imprecise. > https://github.com/shopspring/decimal#faq > http://floating-point-gui.de/basic/ > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Working with Floating-Point numbers
When working with Floating-point values in Go, what considerations need to be made? The same for any other language? The Spec says that "Floating-point values are comparable and ordered" https://golang.org/ref/spec#Comparison_operators So is comparing by some epsilon value not needed? or only for computed values? http://www.cygnus-software.com/papers/comparingfloats/Comparing%20floating%20point%20numbers.htm What is recommended (without external packages) when multiplying or adding Floating-point values? I know that internally those operations can be imprecise. https://github.com/shopspring/decimal#faq http://floating-point-gui.de/basic/ -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
