Hi Xiao-Yong,
the problem with the *scanf() *(and also with the *printf()*) functions
is that text of numbers
is different from APL, for example *-* vs. *¯*, complex numbers, etc.
I therefore believe it would be more useful to have a *⎕CR* variant that
avoids full
parsing and execution of its argument (which *⍎* does). Actually *⎕TF*
is already doing this
and should be much faster than *⍎*, for example:
* ⍝ create numeric variable**
** R←1.1 2J2 4 1R2.2 ¯5 6E¯2 **
****
** ⍝ convert variable into text (to be written to a file)**
** ⎕←TEXT←1 ⎕TF 'R'**
**NR 1 6 1.1000000000000001 2J2 4
¯5.8850111725534582E¯1J8.0849640381959009E¯1 ¯5 **6E¯2**
****
** )ERASE R*
*** ⍝ read text back from file and re-create variable**
** 1 ⎕TF TEXT**
**** R**
**1.1 2J2 4 ¯0.5885011173J0.8084964038 ¯5 0.06**
*
The *1 ⎕TF* record format is fairly simple (record type (N) followed by
the variable name (R in the example) , rank, and shape of the value).
The inverse *1 ⎕TF* tokenizes the string but does, unlike *⍎*, neither
parse nor execute it.
Please use *SVN 745* since I have fixed some *1 ⎕TF* bugs and improved
its error reporting.
/// Jürgen
On 06/16/2016 12:35 AM, Xiao-Yong Jin wrote:
Hi Jürgen,
Just realized my script got much slower (⍕ on a few million numbers from a text
file) with these changes. Since you have printf in ⎕FIO, can you please add
scanf, fscanf, and strto* functions to ⎕FIO, too?
In addition, the tokenizer seems to be confused with exponents.
1E9
1000000000
1E10
1E10
1E9×1E9
1E18
?1E10
3942470777
2?1E10
DOMAIN ERROR
2?1E10
^^
Wouldn't anything below 9E18 be parsed as an integer?
Best,
Xiao-Yong
On Jun 13, 2016, at 9:24 AM, Xiao-Yong Jin <jinxiaoy...@gmail.com> wrote:
Yes, they work. Thanks.
On Jun 11, 2016, at 9:29 AM, Juergen Sauermann <juergen.sauerm...@t-online.de>
wrote:
Hi Xiao-Yong,
thanks, fixed in SVN 740. I haven't checked )DUMP and )OUT but I suppose
they work now since the fault was in the tokenizer (which is also used by
)LOAD and )IN).
/// Jürgen
On 06/10/2016 10:34 PM, Xiao-Yong Jin wrote:
Hi Jürgen,
Thanks. I found more floating point reproduction issues.
⎕PP←17
x-y←x←○3 4
0 0
x-⍎⍕x
0 1.7763568394002505E¯15
x-¯14⎕CR 14⎕CR x
0 0
2⎕TF 2⎕TF ‘y'
y
y
9.4247779607693793 12.566370614359172
x
9.4247779607693793 12.566370614359172
x-○3 4
0 0
y-○3 4
0 ¯1.7763568394002505E¯15
x-y
0 1.7763568394002505E¯15
9.4247779607693793 12.566370614359172-○3 4
0 ¯1.7763568394002505E¯15
The exact representation by 14⎕CR works great (as in one of the ISO CF
implementations), but both ⎕TF and ⍎⍕ fail to reproduce the exact number.
Since you last change, the )save )load does keep the exact values, and I looked
at the saved workspace file, the numbers are
146 <Ravel vid="1" cells="⁴9.4247779607693793⁴12.566370614359171"/>
147 <Ravel vid="2" cells="⁴9.4247779607693793⁴12.566370614359172"/>
185 <Symbol name="x" stack-size="1">
186 <Variable vid="2"/>
187 </Symbol>
188
189 <Symbol name="y" stack-size="1">
190 <Variable vid="1"/>
191 </Symbol>
Here, the last digit of y is 1 instead of 2, as shown in the REPL.
So it seems the routine used to format numbers has some problem with the last
digits, even if with ⎕PP=17? Or it’s just the reader has some problem?
In addition, )dump and )out still changes the floating point number, but
perhaps that is the same issue as in ⎕TF and ⍎⍕?
On Jun 7, 2016, at 3:29 PM, Juergen Sauermann <juergen.sauerm...@t-online.de>
wrote:
Hi Xiao-Yong,
OK - SVN 739.
/// Jürgen
On 06/07/2016 08:16 PM, Xiao-Yong Jin wrote:
Hi Jürgen,
Thanks, though the current behavior still does not give the exact number bit by bit.
Can you change it to %.17g, or std::numeric_limits<double>::max_digits10?
In addition, is it OK to raise the maximum allowed ⎕PP to 17?
Best,
Xiao-Yong
On Jun 7, 2016, at 12:37 PM, Juergen Sauermann <juergen.sauerm...@t-online.de>
wrote:
Hi Xiao-Yong,
thanks, fixed in SVN 738.
/// Jürgen
On 06/07/2016 08:13 AM, Xiao-Yong Jin wrote:
Hello,
Is the following behavior intended? Note the x value after load.
)clear
CLEAR WS
x←.12345678901234567890
⎕pp←16
x
0.1234567890123457
)wsid tmp
WAS CLEAR WS
)save tmp
2016-06-07 01:09:15 (GMT-5)
)clear
CLEAR WS
)load tmp
SAVED 2016-06-07 01:09:15 (GMT-5)
x
0.123457
⎕pp
16
