I can't easily find the document online without having to pay for it, but doesn't the Wikipedia page contain all the information you need? https://en.m.wikipedia.org/wiki/IEEE_754
On 9 Jan 2018 12:14 am, "Juergen Sauermann" <juergen.sauerm...@t-online.de> wrote: > Hi Jay, > > I am still puzzled by the ISO description (and can't find the "IEEE > standard for Binary Floating-Point Arithmetic (754)" > referenced in the standard. > > Would you be able to provide the expected expected output of your example > below? > > If I follow the ISO description of mod in the ISO APL standard word by > word then I am getting pretty odd values at times. > > Best Regards, > /// Jürgen > > > On 01/08/2018 02:19 PM, Jay Foad wrote: > > Yes, thanks! Now, when ⎕CT=0 there are some odd results: > > ⎕CT←0 > A←(-⌽A),0,A←1e¯200 1e¯100 1 1e100 1e200 > A∘.|A > 0E0 ¯1E100 ¯1E0 ¯1E¯100 ¯1E¯200 0 0E0 0E0 ¯1E200 0E0 0E0 > 0E0 0E0 ¯1E0 ¯1E¯100 ¯1E¯200 0 0E0 0E0 ¯1E100 0E0 0E0 > 0E0 0E0 0E0 ¯1E¯100 ¯1E¯200 0 0E0 0E0 0E0 0E0 0E0 > 0E0 0E0 0E0 0E0 ¯1E¯200 0 0E0 0E0 0E0 0E0 0E0 > 0E0 0E0 0E0 0E0 0E0 0 0E0 0E0 0E0 0E0 0E0 > ¯1E200 ¯1E100 ¯1E0 ¯1E¯100 ¯1E¯200 0 1E¯200 1E¯100 1E0 1E100 1E200 > 0E0 0E0 0E0 0E0 0E0 0 0E0 0E0 0E0 0E0 0E0 > 0E0 0E0 0E0 0E0 0E0 0 1E¯200 0E0 0E0 0E0 0E0 > 0E0 0E0 0E0 0E0 0E0 0 1E¯200 1E¯100 0E0 0E0 0E0 > 0E0 0E0 1E100 0E0 0E0 0 1E¯200 1E¯100 1E0 0E0 0E0 > 0E0 0E0 1E200 0E0 0E0 0 1E¯200 1E¯100 1E0 1E100 0E0 > 1e200|¯1 > 1E200 > > The standard explicitly says that the result should never be the same as > the (non-zero) left argument: "If Z is A , return zero." > > Jay. > > On 8 January 2018 at 12:26, Juergen Sauermann < > juergen.sauerm...@t-online.de> wrote: > >> Hi Jay, >> >> maybe *SVN 1036* works better. >> >> /// Jürgen >> >> >> On 01/08/2018 01:02 PM, Jay Foad wrote: >> >> Thanks. With r1035 I get: >> >> A←(-⌽A),0,A←1e¯200 1e¯100 1 1e100 1e200 >> A∘.|A >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> ¯1E200 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> ¯1E200 ¯1E100 ¯1 ¯1E¯100 ¯1E¯200 0 1E¯200 1E¯100 1 1E100 1E200 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >> >> One result stands out: >> >> ¯1E¯200|¯1E200 >> ¯1E200 >> >> The result of A|B (with A non-zero) should be strictly smaller in >> magnitude than A, so this seems very wrong. >> >> Jay. >> >> >> On 8 January 2018 at 11:49, Juergen Sauermann < >> juergen.sauerm...@t-online.de> wrote: >> >>> Hi Jay, >>> >>> thanks, fixed in *SVN 1035*. >>> >>> BTW tryapl.com gives this: >>> >>> * A←1E¯200 1E200 ¯1E¯200 ¯1E200* >>> >>> * A ∘.∣ A* >>> >>> *0 0 0 0 >>> 0 0 0 0 >>> 0 0 0 0 >>> 0 0 0 0* >>> /// Jürgen >>> >>> >>> >>> TOn 01/08/2018 10:29 AM, Jay Foad wrote: >>> >>> Thanks. At r1034 I get: >>> >>> A←(-⌽A),0,A←1e¯200 1e¯100 1 1e100 1e200 >>> A∘.|A >>> DOMAIN ERROR >>> >>> And here's one of the cases that fails: >>> >>> 1e¯200|1e200 >>> DOMAIN ERROR >>> >>> This still seems wrong to me, since the ISO standard for Residue says >>> "Implementations should avoid signalling limit-error in residue" with >>> advice on how to avoid it. (OK, it doesn't mention DOMAIN ERROR, but I >>> think the same principle applies.) >>> >>> Jay. >>> >>> >>> On 6 January 2018 at 11:56, Juergen Sauermann < >>> juergen.sauerm...@t-online.de> wrote: >>> >>>> Hi, >>>> >>>> thanks, fixed in *SVN 1029*. >>>> >>>> /// Jürgen >>>> >>>> >>>> On 01/05/2018 04:37 PM, Jay Foad wrote: >>>> >>>> Yes, that expression hangs on my Linux box too. It gets stuck here: >>>> >>>> FloatCell::bif_residue (this=0x555555ae13a8, Z=0x555555ae24f8, >>>> A=0x555555ae11d8) at FloatCell.cc:643 >>>> 643 while (z < 0.0) z = z + a; >>>> (gdb) p z >>>> $1 = -inf >>>> (gdb) p a >>>> $2 = 9.9999999999999998e-201 >>>> >>>> Jay. >>>> >>>> On 5 January 2018 at 15:24, Xiao-Yong Jin <jinxiaoy...@gmail.com> >>>> wrote: >>>> >>>>> 1e¯200|1e200 hangs on my mac. >>>>> >>>>> > On Jan 5, 2018, at 6:57 AM, Juergen Sauermann < >>>>> juergen.sauerm...@t-online.de> wrote: >>>>> > >>>>> > Hi Jay, >>>>> > >>>>> > hmm, interesting. I am getting this: >>>>> > >>>>> > A←(-⌽A),0,A←1e¯200 1e¯100 1 1e100 1e200 >>>>> > A∘.|A >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > ¯1E200 ¯1E100 ¯1 ¯1E¯100 ¯1E¯200 0 1E¯200 1E¯100 1 1E100 1E200 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > 0E0 0E0 0 0E0 0E0 0 0E0 0E0 0 0E0 0E0 >>>>> > >>>>> > I suppose it is one of the A[i] ∣ A[j] which causes the hanging so >>>>> it would >>>>> > be interesting to know which one. Probably one with +/- 1E¯200 or >>>>> 1E¯100. >>>>> > >>>>> > Best Regards, >>>>> > /// Jürgen >>>>> > >>>>> > >>>>> > On 01/05/2018 12:16 PM, Jay Foad wrote: >>>>> >> At svn r1028 on Linux I get: >>>>> >> >>>>> >> A←(-⌽A),0,A←1e¯200 1e¯100 1 1e100 1e200 >>>>> >> A∘.|A >>>>> >> (hangs) >>>>> >> >>>>> >> Jay. >>>>> > >>>>> >>>>> >>>> >>>> >>> >>> >> >> > >
