sinus.txt

\ *********************************************************************
\ Sinus and Cosinus
\    Filename:      sinus.txt
\    Date:          10 jun 2019
\    File Version:  1.0
\    Copyright:     Marc PETREMANN
\    Author:        Marc PETREMANN
\    GNU General Public License
\ *********************************************************************

\ Sinus and Cosinus
\ Use table calculating integer sin.
\ Get values scaled by 10K.

decimal
-sinus
marker -sinus

: sm/rem ( d1 n1 -- n2 n3 )
  2dup xor >r over >r
  abs >r dabs r> um/mod
  swap r> ?negate
  swap r> ?negate
;
: /mod ( n1 n2 -- n3 n4 )
  >r s>d r> sm/rem
;
: mod ( n1 n2 -- n3 )
  /mod drop
;

flash
create sintab  \ 0...90 Grad, Index in Grad
0000 ,  0175 ,  0349 ,  0523 ,  0698 ,  
0872 ,  1045 ,  1219 ,  1392 ,  1564 ,
1736 ,  1908 ,  2079 ,  2250 ,  2419 ,  
2588 ,  2756 ,  2924 ,  3090 ,  3256 ,
3420 ,  3584 ,  3746 ,  3907 ,  4067 ,  
4226 ,  4384 ,  4540 ,  4695 ,  4848 ,
5000 ,  5150 ,  5299 ,  5446 ,  5592 ,  
5736 ,  5878 ,  6018 ,  6157 ,  6293 ,
6428 ,  6561 ,  6691 ,  6820 ,  6947 ,  
7071 ,  7193 ,  7314 ,  7431 ,  7547 ,
7660 ,  7771 ,  7880 ,  7986 ,  8090 ,  
8192 ,  8290 ,  8387 ,  8480 ,  8572 ,
8660 ,  8746 ,  8829 ,  8910 ,  8988 ,  
9063 ,  9135 ,  9205 ,  9272 ,  9336 ,
9397 ,  9455 ,  9511 ,  9563 ,  9613 ,  
9659 ,  9703 ,  9744 ,  9781 ,  9816 ,
9848 ,  9877 ,  9903 ,  9925 ,  9945 ,  
9962 ,  9976 ,  9986 ,  9994 ,  9998 ,
10000 ,

: sinus@   ( grad ---)
    2* sintab + @ ;
: sin  ( grad -- sinus )
    dup 0< >r abs
    360 mod
    dup 180 > 
    if 
        180 - true >r 
    else 
        false >r 
    then
    dup  90 > 
    if 
        180 swap - 
    then
    sinus@
    r> if negate then
    r> if negate then ;
: cos
    90 + sin ;