amforth-devel — Development discussion and user support

[Amforth-devel] This mailing list available as gmane.comp.lang.forth.amforth

[Marcin C. <sa...@sa...>]

Hello,

This is just to announce that this very mailing list is available
also via NNTP (newsreader) or HTTP (web browser) at gmane.org.

Just point your newsreader to:

nntp://news.gmane.org/gmane.comp.lang.forth.amforth

or go to:

http://dir.gmane.org/gmane.comp.lang.forth.amforth

and pick one of the three web interfaces available.

An archive of almost all previous post is there, so
the context is (mostly) preseved. 

Have fun!

--Marcin

Re: [Amforth-devel] Bug - ".s"

[Marcin C. <sa...@sa...>]

On Tue, 7 Sep 2010, pito wrote:

> Hi Matthias,
> not sure, but I think the
>> 123 345 567
> ok
>> .s
> 0 16377 567
> 1 16379 345
> 2 16381 123
> ok
>> sp0 .
> 16383  ok
>
> shall be in following form (when assuming lower byte first). Am I
> right?
>> .s
> 0 16378 567
> 1 16380 345
> 2 16382 123

Nope.

2223  ok
> .s
  ok
> 2
  ok
> 3
  ok
> 4
  ok
> sp0 .
2223  ok
> .s 
0 2217 4 <-- sp@
1 2219 3 
2 2221 2
  (2223)  <-- sp0
> sp@ .
2217  ok

A cell is 2 bytes (a word) wide.

--Marcin

[Amforth-devel] Bug - ".s"

[pito <pi...@vo...>]

Hi Matthias,
not sure, but I think the 
> 123 345 567
ok
> .s
0 16377 567 
1 16379 345 
2 16381 123 
ok
> sp0 .
16383  ok

shall be in following form (when assuming lower byte first). Am I
right?
> .s
0 16378 567 
1 16380 345 
2 16382 123 
P.

[Amforth-devel] Return stack dump - .rls

[pito <pi...@vo...>]

Hi, here is an utility which help you see the Rstack:

\ based on .s, Pito 2010
marker -rstackdump

: rdepth rp0 rp@ - 2/  1- 1- ; 
\ ONE LINE SIGNED RSTACK
: .rls
rp@  1-                  \ alignment vs. .s ???
." [TOR> " 
rdepth 1- 0 ?do   
dup i
2* + 
@ 6 .r 
loop
drop ." ]"
;

----------------------

Ex:

: ? .sls cr .rls cr ;
: rtest
?
-8888 -8888 -8888 -8888 ? >r ? >r ? >r ? >r ?
r> ? r> ? r> ? r> ? 
drop drop drop drop ?
;
: rtest1 .rls ;
: rtest2 rtest1 ;
: rtest3 rtest2 ;

> rtest
[TOS> ]
[TOR>  10748 10761 10770  1539   934]
[TOS>  -8888 -8888 -8888 -8888]
[TOR>  10748 10761 10779  1539   934]
[TOS>  -8888 -8888 -8888]
[TOR>  10748 10761 10781 -8888  1539   934]
[TOS>  -8888 -8888]
[TOR>  10748 10761 10783 -8888 -8888  1539   934]
[TOS>  -8888]
[TOR>  10748 10761 10785 -8888 -8888 -8888  1539   934]
[TOS> ]
[TOR>  10748 10761 10787 -8888 -8888 -8888 -8888  1539   934]
[TOS>  -8888]
[TOR>  10748 10761 10789 -8888 -8888 -8888  1539   934]
[TOS>  -8888 -8888]
[TOR>  10748 10761 10791 -8888 -8888  1539   934]
[TOS>  -8888 -8888 -8888]
[TOR>  10748 10761 10793 -8888  1539   934]
[TOS>  -8888 -8888 -8888 -8888]
[TOR>  10748 10761 10795  1539   934]
[TOS> ]
[TOR>  10748 10761 10800  1539   934]
ok
> .rls
[TOR>  10748  1539   934] ok
> rtest1
[TOR>  10748 10808  1539   934] ok
> rtest2
[TOR>  10748 10808 10816  1539   934] ok
> rtest3
[TOR>  10748 10808 10816 10824  1539   934] ok
> 

Re: [Amforth-devel] HOW TO - Assembler in anmforth

[pito <pi...@vo...>]

10. how the local .asm variables (used in asm rouitne shall be
handled (e.g. where in ram to place the local variables).

----- PŮVODNÍ ZPRÁVA -----
Od: "pito" <pi...@vo...>
Komu: amf...@li...
Předmět: HOW TO - Assembler in anmforth 
Datum: 7.9.2010 - 8:42:46

> Hi Matthias and co.,
> I'd like to ask how to start working with
> assembler in amforth. This
> might be of general interest, therefore HOW TO. 
> The example could be the timer int routine:
> : tick_isr  _one timer 2@ d+ timer 2! ;
> which does "timer = timer + 1" where timer is
> double integer. I've
> seen usart routines and Lubos' routines in asm,
> however generaly the
> Q:
> 
> 1. is there any recommended structure or frame for
> writing assembler
> words
> 1a. is there any recomemnded structure or frame
> for writing
> assembler interrupt handlers
> 2. how the data from data stack (or from return
> stack) are passed to
> assembler
> 3. how the data are passed from asm. back to data
> stack or return
> stack
> 4. how the external variables (defined as words)
> are accessed from
> assembler
> 5. how the data stack is duped or droped from
> assembler
> 6. what shall be poped and pushed in asm. routine
> (when entering and
> leaving it)
> 7. how the asm return stack is handled (imagine we
> need nested calls
> in asm)
> 8. how the ram, eprom can be accessed from asm
> 9. how the asm code shall be compiled (? via LP's
> asm or via
> avrasm.)
> 
> Thanks, Pito
> 

[Amforth-devel] HOW TO - Assembler in anmforth

[pito <pi...@vo...>]

Hi Matthias and co.,
I'd like to ask how to start working with assembler in amforth. This
might be of general interest, therefore HOW TO. 
The example could be the timer int routine:
: tick_isr  _one timer 2@ d+ timer 2! ;
which does "timer = timer + 1" where timer is double integer. I've
seen usart routines and Lubos' routines in asm, however generaly the
Q:

1. is there any recommended structure or frame for writing assembler
words
1a. is there any recomemnded structure or frame for writing
assembler interrupt handlers
2. how the data from data stack (or from return stack) are passed to
assembler
3. how the data are passed from asm. back to data stack or return
stack
4. how the external variables (defined as words) are accessed from
assembler
5. how the data stack is duped or droped from assembler
6. what shall be poped and pushed in asm. routine (when entering and
leaving it)
7. how the asm return stack is handled (imagine we need nested calls
in asm)
8. how the ram, eprom can be accessed from asm
9. how the asm code shall be compiled (? via LP's asm or via
avrasm.)

Thanks, Pito

Re: [Amforth-devel] A collection of new ".s" - for fun

[pito <pi...@vo...>]

A test for .sls and .sla:

\ a quick test for one line .s

marker -testsdtot

: stest
-12345
.sls cr
5 0 do dup .sls cr loop
5 0 do drop .sls cr loop
drop
.sls cr
;

: stest1
$AAAA
.sla cr
5 0 do dup .sla cr loop
5 0 do drop .sla cr loop
drop
.sla cr
;
----------------------------------

EX:

> stest
[TOS> -12345]
[TOS> -12345-12345]
[TOS> -12345-12345-12345]
[TOS> -12345-12345-12345-12345]
[TOS> -12345-12345-12345-12345-12345]
[TOS> -12345-12345-12345-12345-12345-12345]
[TOS> -12345-12345-12345-12345-12345]
[TOS> -12345-12345-12345-12345]
[TOS> -12345-12345-12345]
[TOS> -12345-12345]
[TOS> -12345]
[TOS> ]
ok
> stest1
[TOS> -21846]
[TOS>  43690]
[TOS>   AAAA]
[TOS> -21846-21846]
[TOS>  43690 43690]
[TOS>   AAAA  AAAA]
[TOS> -21846-21846-21846]
[TOS>  43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846-21846]
[TOS>  43690 43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846-21846-21846]
[TOS>  43690 43690 43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846-21846-21846-21846]
[TOS>  43690 43690 43690 43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA  AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846-21846-21846]
[TOS>  43690 43690 43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846-21846]
[TOS>  43690 43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA  AAAA]
[TOS> -21846-21846-21846]
[TOS>  43690 43690 43690]
[TOS>   AAAA  AAAA  AAAA]
[TOS> -21846-21846]
[TOS>  43690 43690]
[TOS>   AAAA  AAAA]
[TOS> -21846]
[TOS>  43690]
[TOS>   AAAA]
[TOS> ]
[TOS> ]
[TOS> ]
ok
> 

[Amforth-devel] A collection of new ".s" - for fun

[pito <pi...@vo...>]

Hi, this is a collection of .s variations in various shapes and
bases.
Have a fun! Pito.


\ Some new .s
\ by Pito 2010-09-06

marker -newdots

: u.r       ( s n -- )   0 swap ud.r ;  \ comment if installed


\ ONE LINE HEXA STACK
: .slh
sp@ 
." [TOS> " 
depth 1- 0 ?do
dup i
2* +
base @ swap hex @ 6 u.r base !
loop
drop ." ]"
;


\ ONE LINE UNSIGNED STACK
: .slu
sp@ 
." [TOS> " 
depth 1- 0 ?do
dup i
2* +
@ 6 u.r
loop
drop ." ]"
\ cr .slh
;


\ ONE LINE SIGNED STACK
: .sls
sp@ 
." [TOS> " 
depth 1- 0 ?do
dup i
2* +
@ 6 .r 
loop
drop ." ]"
\ cr .slh
;

\ ONE LINE SIGNED AND HEXA STACK
: .sld
sp@ 
." [TOS> " 
depth 1- 0 ?do
dup i
2* +
@ 6 .r 
loop
drop ." ]"
cr .slh
;

\ ONE LINE SIGNED AND UNSIGNED AND HEXA STACK
: .sla
sp@ 
." [TOS> " 
depth 1- 0 ?do
dup i
2* +
@ 6 .r 
loop
drop ." ]"
cr .slu
cr .slh
;

\ IN COLUMNS NO ADDRR UNSIGNED SIGNED HEXA 
: .sc
sp@ 
depth 1- 0 ?do
dup 
i dup dup 0 = if ." TOS>" drop else negate 4 .r then   	
2* +      \ dup 7 u.r 	 	( prints the address )
dup dup @ 7 u.r @ 7 .r base @ swap hex @ 6 u.r base !
cr
loop
drop
;

\ IN COLUMNS WITH ADDRR UNSIGNED SIGNED HEXA 
: .sch
sp@ 
depth 1- 0 ?do
dup i
dup negate 4 .r
2* + dup 7 u.r 	 	( prints the address )
dup dup @ 7 u.r @ 7 .r base @ swap hex @ 6 u.r base !
cr
loop
drop
;


\ AN EXPERIMENT WITH 2DECIMAL
: .scd
sp@ depth 1- 0 ?do
dup i
dup u.      ( gives the "index" )
2* + dup u. ( prints the address )
i $0001 and 0 = if dup @ u. 2@ d.  else @ u. then ( content )
cr
loop
drop
;

\ AN EXPERIMENT WITH 2DECIMAL and FLOAT
: .scf
sp@ depth 1- 0 ?do
dup i
dup 4 u.r      ( gives the "index" )
2* + dup 8 u.r ( prints the address )
i $0001 and 0 = if dup dup @ 8 u.r 2@ 12 d.r ."  " f@ fs. else @ 8
u.r then 
cr
loop
drop
;

\ AN EXPERIMENT WITH 2DECIMAL and FLOAT
: .scf1
sp@ depth 1- 0 ?do
dup i
dup negate 4 .r      ( gives the "index" )
2* + dup 7 u.r ( prints the address )
i $0001 and 0 = if dup dup @ 7 u.r 2@ 13 d.r ."   " f@ fs. else @ 7
u.r then 
cr
loop
drop
;
\ -------------------------------------------------
Ex:

> _pi _ln2 -1234567890.
ok
> .slh
[TOS>   B669  FD2E  3F31  7217  4049   FDB  FD2E  3F31  7217  4049  
FDB] ok
> .slu
[TOS>  46697 64814 16177 29207 16457  4059 64814 16177 29207 16457 
4059] ok
> .sls
[TOS> -18839  -722 16177 29207 16457  4059  -722 16177 29207 16457 
4059] ok
> .sld
[TOS> -18839  -722 16177 29207 16457  4059  -722 16177 29207 16457 
4059]
[TOS>   B669  FD2E  3F31  7217  4049   FDB  FD2E  3F31  7217  4049  
FDB] ok
> .sla
[TOS> -18839  -722 16177 29207 16457  4059  -722 16177 29207 16457 
4059]
[TOS>  46697 64814 16177 29207 16457  4059 64814 16177 29207 16457 
4059]
[TOS>   B669  FD2E  3F31  7217  4049   FDB  FD2E  3F31  7217  4049  
FDB] ok
> .sc
TOS>  46697 -18839  B669
-1  64814   -722  FD2E
-2  16177  16177  3F31
-3  29207  29207  7217
-4  16457  16457  4049
-5   4059   4059   FDB
-6  64814   -722  FD2E
-7  16177  16177  3F31
-8  29207  29207  7217
-9  16457  16457  4049
-10   4059   4059   FDB
ok
> .sch
0  16361  46697 -18839  B669
-1  16363  64814   -722  FD2E
-2  16365  16177  16177  3F31
-3  16367  29207  29207  7217
-4  16369  16457  16457  4049
-5  16371   4059   4059   FDB
-6  16373  64814   -722  FD2E
-7  16375  16177  16177  3F31
-8  16377  29207  29207  7217
-9  16379  16457  16457  4049
-10  16381   4059   4059   FDB
ok
> .scd
0 16361 46697 -1234567890 
1 16363 64814 
2 16365 16177 1060205079 
3 16367 29207 
4 16369 16457 1078530011 
5 16371 4059 
6 16373 64814 -47300815 
7 16375 16177 
8 16377 29207 1914126409 
9 16379 16457 
10 16381 4059 266027005 
ok
> .scf
0   16361   46697 -1234567890 -3.4867067E-6 
1   16363   64814
2   16365   16177  1060205079 6.9314709E-1 
3   16367   29207
4   16369   16457  1078530011 3.1415927 
5   16371    4059
6   16373   64814   -47300815 -1.4475877E37 
7   16375   16177
8   16377   29207  1914126409 2.9958398E30 
9   16379   16457
10   16381    4059   266027005 2.1619697E-29 
ok
> .scf1
0  16361  46697  -1234567890  -3.4867067E-6 
-1  16363  64814
-2  16365  16177   1060205079  6.9314709E-1 
-3  16367  29207
-4  16369  16457   1078530011  3.1415927 
-5  16371   4059
-6  16373  64814    -47300815  -1.4475877E37 
-7  16375  16177
-8  16377  29207   1914126409  2.9958398E30 
-9  16379  16457
-10  16381   4059    266027005  2.1619697E-29 
ok
>

Re: [Amforth-devel] printing floats

[李雪愚 <sno...@gm...>]

hi, Leon,

Maybe you can port the float lib of PForth to amforth:

  http://pforth.googlecode.com/svn/trunk/fth/floats.fth

unitTest: http://pforth.googlecode.com/svn/trunk/fth/t_floats.fth

Best Regards


> I've finally added a function to output floats (in scientific notation):
> 
>> 355 s>f 113 s>f f/ fs.
> 3.1415927  ok
>> 1 s>f f2/ f2/ f2/ f2/ fs.
> 6.25E-2  ok
>> 12345 s>f fs.
> 1.23449993E4  ok
> 
> You can see from the second example that rounding problems do happen. That can 
> be avoided... if you don't mind coding with decuple length integers (need to 
> be able to store up to 2^154). See the pdf at:
> 
> http://portal.acm.org/citation.cfm?id=93559
> 
> So I'm going to stick with this simpler -- but less accurate -- method for the 
> moment (also in the pdf) -- I'll work on input before spending more time with 
> output (similar problems exist -- maybe there are easier solutions). As usual, 
> the code is available at:
> 
> http://github.com/lnmaurer/amforth-float
> 
> -Leon
> 
> PS I'm not sure if these type of updates are of general interest, but there's 
> been a lot of floating point stuff going around, so I'll keep sending them for 
> the moment.
> 
> ------------------------------------------------------------------------------
> This SF.net Dev2Dev email is sponsored by:
> 
> Show off your parallel programming skills.
> Enter the Intel(R) Threading Challenge 2010.
> http://p.sf.net/sfu/intel-thread-sfd
> _______________________________________________
> Amforth-devel mailing list
> Amf...@li...
> https://lists.sourceforge.net/lists/listinfo/amforth-devel

[Amforth-devel] 'read' an Edefered word?

[Kalus M. <mic...@on...>]

Hi.

: xx 11 22 33 ;
Edefer zz
' xx is zz

Then later on I want to examin the system: What words do all my  
Edefered word stand for?
How can I find out which word has been put there in an Edefered word?

' zz 1+ i@
gives the adr in eeprom where the xt of xx is.

example:
» 62 e@ .
5390  ok
» ' xx .
5390  ok
»

But how do I find out the NFA of XT 5390 now?

Michael

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

FYI: calc with f/ instead of f*:
> _1 _pi f* _1e15 f/ timer-start fs. timer-stop fs.
3.1415911E-15 6.5011706E-1  ok
> _1 _pi f* _1e-15 f/ timer-start fs. timer-stop fs.
3.1415932E15 7.0254588E-1  ok
> _-1 _pi f* _1e15 f/ timer-start fs. timer-stop fs.
-3.1415911E-15 6.3963132E-1  ok
> _-1 _pi f* _1e-15 f/ timer-start fs. timer-stop fs.
-3.1415932E15 7.0254588E-1  ok
> 
Duration of f/ (@25MHz, in seconds):
> _1 _pi f* _1e15 timer-start f/ timer-stop fswap fs. fs.
3.1415911E-15 9.4371824E-2  ok
> _1 _pi f* _1e-15 timer-start f/ timer-stop fswap fs. fs.
3.1415932E15 8.388607E-2  ok
> _-1 _pi f* _1e15 timer-start f/ timer-stop fswap fs. fs.
-3.1415911E-15 8.388607E-2  ok
> _-1 _pi f* _1e-15 timer-start f/ timer-stop fswap fs. fs.
-3.1415932E15 8.388607E-2  ok
>

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

FS. duration (with latest Leon's fs., latest float$constants, time
in seconds, @25MHz):
> _1 _pi _1e15 f* f* timer-start fs. timer-stop fs.
3.141593E15 6.5011706E-1  ok
> _1 _pi _1e-15 f* f* timer-start fs. timer-stop fs.
3.1415899E-15 6.1865978E-1  ok
> _-1 _pi _1e15 f* f* timer-start fs. timer-stop fs.
-3.141593E15 6.5011706E-1  ok
> _-1 _pi _1e-15 f* f* timer-start fs. timer-stop fs.
-3.1415899E-15 6.2914553E-1  ok
> Pito

----- PŮVODNÍ ZPRÁVA -----
Od: "pito" <pi...@vo...>
Komu: leo...@gm..., amf...@li...
Předmět: Re: [Amforth-devel] printing floats
Datum: 5.9.2010 - 10:10:20

> Bug in latest source:
> \THREE VERSIONS, PICK YOUR POISON  <<<<<<
> 
> 
> ------------------------------------------------------------------------------
> > This SF.net Dev2Dev email is sponsored by:
> 
> Show off your parallel programming skills.
> Enter the Intel(R) Threading Challenge 2010.
> http://p.sf.net/sfu/intel-thread-sfd
> _______________________________________________
> Amforth-devel mailing list
> Amf...@li...
> https://lists.sourceforge.net/lists/listinfo/amforth-devel

Re: [Amforth-devel] Some useful Float Constants

[pito <pi...@vo...>]

The most precise version:

\

marker _float$constants_

\ some float constants

$0fdb $4049		fconstant 		_pi

$04f3 $3fb5 	fconstant		_sqrt2

$f854 $402d		fconstant 		_e

$7217 $3f31		fconstant 		_ln2

$5d8d $4013		fconstant 		_ln10

$209a $3e9a		fconstant 		_log2


$0000 $3f00 fconstant 			_half
$aaaa $3eaa fconstant 			_third

5 s>f 127 s>f f/ fconstant 		_mm2inch

10 s>f fconstant				_10
100 s>f fconstant				_1e2
1000 s>f fconstant				_1e3
10000 s>f fconstant				_1e4
_1e3 _1e3 f* fconstant 			_1e6
_1e6  _1e3 f* fconstant 		_1e9
_1e9  _1e3 f* fconstant 		_1e12
_1e12  _1e3 f* fconstant 		_1e15
_1e15  _1e3 f* fconstant 		_1e18

$cccc $3dcc fconstant 			_1e-1
$d70a $3c23 fconstant 			_1e-2
$126e $3a83 fconstant 			_1e-3
$b717 $38d1 fconstant			_1e-4
$37bd $3586 fconstant			_1e-6
$705f $3089 fconstant 			_1e-9
$bccc $2b8c fconstant			_1e-12
$1d7c $2690 fconstant			_1e-15
$92ee $2193 fconstant 			_1e-18

0 s>f fconstant _0
-1 s>f fconstant _-1
1 s>f fconstant _1

Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

Bug in latest source:
\THREE VERSIONS, PICK YOUR POISON  <<<<<<

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

Thanks! I will play with it today. From my prospective no objection
to work with 4.1. 
Pito


> Any objections if I make the floating point code
> version 4.1 dependent so that 
> I can use 2>R, 2R> and 2LITERAL?
> -Leon

Re: [Amforth-devel] printing floats

[Leon N M. <leo...@gm...>]

I did what I mentioned earlier and replaced the repeated division in FS. by 
repeated multiplication and one division. I didn't benchmark it rigorously, 
but it seems to be nearly as fast as the method where we multiply by 1/10, but 
it doesn't have the accuracy problems. For example:

The new method:
> _pi _1e3 f* fs.
3.1415925E3  ok
> _pi _1e3 f/ fs.
3.1415923E-3  ok

The multiply by 1/10 method:
> _pi _1e3 f* fs.
3.1415915E3  ok
> _pi _1e3 f/ fs.
3.1415923E-3  ok

So the new method restricts the error to the least significant digit printed, 
where as the multiply by 1/10 method does not.

Unless this turns out to be much slower than I expect, I'll run with this new 
method until f/ can be improved.

Any objections if I make the floating point code version 4.1 dependent so that 
I can use 2>R, 2R> and 2LITERAL?
-Leon

>Saturday 04 September 2010
>From: "pito" <pi...@vo...>
>Subject: Re: [Amforth-devel] printing floats
> Yes, 0.1 is $3dcccccc = 0.09999999403953552
> from that the result will be 3.14158984478e+/-15 (shall be
> 3.1415926535e+/-15).
> Our result is 3.1415851, or 3.1415874 - so quite precise. However, I
> would simply recommend to print with 4 decimal places only. For
> atmega users -3.1415E-27 might be ok, I guess. And nobody will be
> nervous (:-)). Q: can we set the number of decimal places to be
> print somehow? Pito

Re: [Amforth-devel] printing floats

[Leon N. M. <leo...@gm...>]

Engineering notation is also on the todo list (see FE. in the standard). I 
don't know about the HP25, but many older HP calculators used the Saturn 
microprocessor that could handle 16 BCD digits.

http://en.wikipedia.org/wiki/Saturn_(microprocessor)

I've seen the 4th stuff -- definitely a lot of good material (I wish I'd seen 
it sooner).

-Leon

On Saturday, September 04, 2010 03:30:56 pm you wrote:
> A point to fs. For small systems float with 3-4 decimal places is
> perfect when measuring standard stuff except when measure frequency
> or time.  What could be nice to have is engineering notation. I have
> got it on my HP-25, and frankly, I do not understand how they did it
> on such small footprint. Not sure whether it's processor calculates
> in BCD directly, then it is easy. Once I did it on pic in C, but the
> code was big as I had needed log(). Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

A point to fs. For small systems float with 3-4 decimal places is
perfect when measuring standard stuff except when measure frequency
or time.  What could be nice to have is engineering notation. I have
got it on my HP-25, and frankly, I do not understand how they did it
on such small footprint. Not sure whether it's processor calculates
in BCD directly, then it is easy. Once I did it on pic in C, but the
code was big as I had needed log(). Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

Leon, did you see the ans float from the 4th forth? There is an ans
float library and zen float library as well. Lot of routines for
both.. Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

The f* is ~4.7ms and f/ is ~91ms (not 13ms as I had written, sorry)
at 25MHz clock. So we went from 1.7sec to 0.5sec when printed E15,
that is 1.7-0.5 = ~1.2sec less.
check: 15 * (0.091-0.0047) = ~1.29sec less.. P.

Re: [Amforth-devel] printing floats

[Leon N. M. <leo...@gm...>]

At the moment, there's no way to print a fixed number of digits, but it won't 
be hard to do -- a simple way would be to replace the last begin-while-repeat 
look with a do-loop of the number of digits you want and strip out the stuff 
dealing with M.

It's something I hope to get around to eventually -- it's in the ANS standard 
with the SET-PRECISION word. I'll probably make it possible to have a set 
number of significant digits or to use the current method.

-Leon

On Saturday, September 04, 2010 02:31:16 pm you wrote:
> Yes, 0.1 is $3dcccccc = 0.09999999403953552
> from that the result will be 3.14158984478e+/-15 (shall be
> 3.1415926535e+/-15).
> Our result is 3.1415851, or 3.1415874 - so quite precise. However, I
> would simply recommend to print with 4 decimal places only. For
> atmega users -3.1415E-27 might be ok, I guess. And nobody will be
> nervous (:-)). Q: can we set the number of decimal places to be
> print somehow? Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

Yes, 0.1 is $3dcccccc = 0.09999999403953552
from that the result will be 3.14158984478e+/-15 (shall be
3.1415926535e+/-15).
Our result is 3.1415851, or 3.1415874 - so quite precise. However, I
would simply recommend to print with 4 decimal places only. For
atmega users -3.1415E-27 might be ok, I guess. And nobody will be
nervous (:-)). Q: can we set the number of decimal places to be
print somehow? Pito

Re: [Amforth-devel] printing floats

[Leon N. M. <leo...@gm...>]

I've avoided division by reciprocal multiplication because it introduces 
rounding errors (.1 in decimal is infinitely repeating in binary). That said, 
we already have some rounding errors, so it may be worth doing -- although 
these new rounding errors do look slightly more severe.

I'll think about it -- the test you can definitely gives me some good 
information.
-Leon

On Saturday, September 04, 2010 02:01:30 pm you wrote:
> Leon, I did following - I put print"#" in f* and print"%" in f/:
> > 987654321. d>f _1e9 f*
> 
> # ok
> 
> > fs.
> 
> %%%%%%%%%%%%%%%%%9.###8###7###6###5###3###6###4E17  ok
> 
> > 987654321. d>f _1e-9 f*
> 
> # ok
> 
> > fs.
> 
> #9.###8###7###6###5###3###2###6E-1  ok
> 
> > 987654321. d>f _1e-9 f/
> 
> % ok
> 
> > fs.
> 
> %%%%%%%%%%%%%%%%%9.###8###7###6###5###4###5###9E17  ok
> 
> > 987654321. d>f _1e-18 f/
> 
> % ok
> 
> > fs.
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%9.###8###7###6###5###5###0###7E26  ok
> 
> > 987654321. d>f _1e-18 f* _1e-12 f*
> 
> ## ok
> 
> > fs.
> 
> ######################9.###8###7###6###4###9###8E-22  ok
> 
> ok
> 
> > 987654321. d>f _1e9 f* _1e12 f*
> 
> ## ok
> 
> > fs.
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%9.###8###7###6###5###3###4###5E29  ok
> 
> So when result with positive exponents E+XX the XX divisions are
> made. Therefore I changed the f/ (13ms) with f*(4ms) in the
> following routine:
> 
> \ if it's too large, make it smaller
> begin
> fdup _10 f>= \ [ 10 s>f ]
> while
> _.1 f*  \ _10 f/ \ [ 10 s>f ] <<<<<<<<< Here
> fnswap 1+ nfswap
> \  ." f>="
> repeat
> 
> So now:
> > 987654321. d>f _1e9 f* _1e12 f*
> 
> ## ok
> 
> > fs.
> 
> #############################9.###8###7###6###5###1###2###5E29  ok
> 
> > 987654321. d>f _1e-18 f* _1e-12 f*
> 
> ## ok
> 
> > fs.
> 
> ######################9.###8###7###6###4###9###8E-22  ok
> 
> 
> So now the conversion with positive exponens (previous f/) i 3x
> 
> faster:
> > : measure
> 
> oktimer-start _1 _pi f* _1e15 f* fs. timer-stop fs. ." sec";
> ok
> 
> > measure
> 
> 3.1415874:E15 4.9283066E-1 sec ok
> 
> > : measure
> 
> oktimer-start _1 _pi f* _1e-15 f* fs. timer-stop fs. ." sec";
> ok
> 
> > measure
> 
> 3.1415851E-15 5.4525948E-1 sec ok
> 
> > : measure
> 
> oktimer-start _-1 _pi f* _1e15 f* fs. timer-stop fs. ." sec";
> ok
> 
> > measure
> 
> -3.1415874:E15 4.9283066E-1 sec ok
> 
> > : measure
> 
> oktimer-start _-1 _pi f* _1e-15 f* fs. timer-stop fs. ." sec";
> ok
> 
> > measure
> 
> -3.1415851E-15 5.4525948E-1 sec ok
> 
> So all fs. are now ~0.5sec.
> I do not know why the colon in the number (:E15), but probably an
> induced bug (:-)).
> Pito

Re: [Amforth-devel] printing floats

[pito <pi...@vo...>]

Leon, I did following - I put print"#" in f* and print"%" in f/:
> 987654321. d>f _1e9 f*
# ok
> fs.
%%%%%%%%%%%%%%%%%9.###8###7###6###5###3###6###4E17  ok
> 987654321. d>f _1e-9 f*
# ok
> fs.
#9.###8###7###6###5###3###2###6E-1  ok
> 987654321. d>f _1e-9 f/
% ok
> fs.
%%%%%%%%%%%%%%%%%9.###8###7###6###5###4###5###9E17  ok
> 987654321. d>f _1e-18 f/
% ok
> fs.
%%%%%%%%%%%%%%%%%%%%%%%%%%9.###8###7###6###5###5###0###7E26  ok
> 987654321. d>f _1e-18 f* _1e-12 f*
## ok
> fs.
######################9.###8###7###6###4###9###8E-22  ok
> 
ok
> 987654321. d>f _1e9 f* _1e12 f*
## ok
> fs.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%9.###8###7###6###5###3###4###5E29  ok

So when result with positive exponents E+XX the XX divisions are
made. Therefore I changed the f/ (13ms) with f*(4ms) in the
following routine:

\ if it's too large, make it smaller
begin
fdup _10 f>= \ [ 10 s>f ]
while
_.1 f*  \ _10 f/ \ [ 10 s>f ] <<<<<<<<< Here
fnswap 1+ nfswap
\  ." f>="
repeat

So now:
> 987654321. d>f _1e9 f* _1e12 f*
## ok
> fs.
#############################9.###8###7###6###5###1###2###5E29  ok
> 987654321. d>f _1e-18 f* _1e-12 f*
## ok
> fs.
######################9.###8###7###6###4###9###8E-22  ok
> 

So now the conversion with positive exponens (previous f/) i 3x
faster:
> : measure
oktimer-start _1 _pi f* _1e15 f* fs. timer-stop fs. ." sec";
ok
> measure
3.1415874:E15 4.9283066E-1 sec ok
> : measure
oktimer-start _1 _pi f* _1e-15 f* fs. timer-stop fs. ." sec";
ok
> measure
3.1415851E-15 5.4525948E-1 sec ok
> : measure
oktimer-start _-1 _pi f* _1e15 f* fs. timer-stop fs. ." sec";
ok
> measure
-3.1415874:E15 4.9283066E-1 sec ok
> : measure
oktimer-start _-1 _pi f* _1e-15 f* fs. timer-stop fs. ." sec";
ok
> measure
-3.1415851E-15 5.4525948E-1 sec ok
> 
So all fs. are now ~0.5sec.
I do not know why the colon in the number (:E15), but probably an
induced bug (:-)).
Pito

Re: [Amforth-devel] printing floats

[Leon N M. <leo...@gm...>]

The current method repeatedly divides (for large numbers) or multiplies (for 
small numbers) by 10 until the float is in the range [1,10). f/ is slow, which 
makes it slow to print large numbers. f* is faster because I saw a way to do 
the math with integers using m* -- I didn't see a similar good way to do this 
with division (partly since it's not left-distributive over addition -- 
a/(b+c) != a/b + a/c, which does hold for multiplication).

That's the short reason for way the small numbers print out faster than the 
large numbers.

I've got an idea or two to speed up fs. (e.g. can replace repeated division by 
repeated multiplication and one division), but f/ is what really needs 
optimization. I'm probably going to hold off on any of that until I get input 
working.

-Leon

>Saturday 04 September 2010
>From: "pito" <pi...@vo...>
>Subject: Re: [Amforth-devel] printing floats
> Nooop, fs. still slow, even with fconstants:
> > measure
> 
> 3.1415851E-15
> 545 ms ok
> 
> > measure
> 
> 3.1415915E15
> 1646 ms ok
> 
> > measure
> 
> -3.1415915E15
> 1646 ms ok
> 
> > measure
> 
> -3.1415851E-15
> 545 ms ok
> 
> P.