Scientific or exponential notation remover

[bplus]

I am testing last function in Steve's Math Evaluator and ran into a curiosity for n = 1 in default Single.

The 0's jump 1 extra 0 between 7 and 8, all other numbers I've tested seem OK

Code: QB64: [Select]

1. _TITLE "N2S$ testing for a scientific notation remover" 'b+ 2020-09-04
2.  
3. ' looks pretty good except for one little bug
4.  
5. IF 1 THEN ' < 0 to skip section, 1 to run section
6.     n = 1 ' has an odd bug jump -7 to -8 moves right 1 extra 0
7.     FOR i = 0 TO 20
8.         PRINT i, N2S$(STR$(n * 10 ^ -i));
9.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n * 10 ^ i))
10.     NEXT
11. END IF
12.  
13. IF 0 THEN '  < 0 to skip section, 1 to run section
14.     n## = 1 ' but this OK too
15.     'n## = 27.0123456789 'OK
16.     'n## = (1 / 3) 'OK
17.     FOR i = 0 TO 20
18.         PRINT i, N2S$(STR$(n## * 10 ^ -i));
19.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n## * 10 ^ i))
20.     NEXT
21. END IF
22.  
23. FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~40 LOC)
24.     'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
25.     'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)
26.     t$ = LTRIM$(RTRIM$(EXP$))
27.     IF LEFT$(t$, 1) = "-" OR LEFT$(t$, 1) = "N" THEN sign$ = "-": t$ = MID$(t$, 2)
28.     dp = INSTR(t$, "D+"): dm = INSTR(t$, "D-")
29.     ep = INSTR(t$, "E+"): em = INSTR(t$, "E-")
30.     check1 = SGN(dp) + SGN(dm) + SGN(ep) + SGN(em)
31.     IF check1 < 1 OR check1 > 1 THEN N2S = EXP$: EXIT SUB 'If no scientic notation is found, or if we find more than 1 type, it's not SN!
32.     SELECT CASE l 'l now tells us where the SN starts at.
33.         CASE IS < dp: l = dp
34.         CASE IS < dm: l = dm
35.         CASE IS < ep: l = ep
36.         CASE IS < em: l = em
37.     END SELECT
38.     l$ = LEFT$(t$, l - 1) 'The left of the SN
39.     r$ = MID$(t$, l + 1): r&& = VAL(r$) 'The right of the SN, turned into a workable long
40.     IF INSTR(l$, ".") THEN 'Location of the decimal, if any
41.         IF r&& > 0 THEN
42.             r&& = r&& - LEN(l$) + 2
43.         ELSE
44.             r&& = r&& + 1
45.         END IF
46.         l$ = LEFT$(l$, 1) + MID$(l$, 3)
47.     END IF
48.     SELECT CASE r&&
49.         CASE 0 'what the heck? We solved it already?
50.             'l$ = l$
51.         CASE IS < 0
52.             FOR i = 1 TO -r&&
53.                 l$ = "0" + l$
54.             NEXT
55.             l$ = "0." + l$
56.         CASE ELSE
57.             FOR i = 1 TO r&&
58.                 l$ = l$ + "0"
59.             NEXT
60.             l$ = l$
61.     END SELECT
62.     N2S$ = sign$ + l$
63. END SUB
64.  
65.  
66.  

@SMcNeill  a puzzle for you.

I don't think this will stop me from using it, as is, though getting this curiosity explained or fixed would be nice :)

[SMcNeill]

I’ll dig into it in a few days.  Today and Tomorrow, I’m down watching over my mom (she’s dealing with early onset Alzheimer's), so it’ll probably be Sunday by the earliest, before I can sort out what’s going on.  ;) 

[SMcNeill]

Good catch!  Negative notation isn't something which we see very often, and the glitch here is mine, instead of QB64s.

1e-8 -- this says we have 1, then shift it to the right 8 places, giving us 0.00000001...

Unfortunately, I simply interpeted it as "add 8 zeros in front", giving us 0.000000001...  This is an extra 0, which we don't actually have!

(In my defense, 1e8 is as simple as "add 8 zeros behind", giving us 100000000...  Unfortunately, the same logic doesn't quite hold true, in this case, for negative exponents.)

The change is extremely simple to implement:

Down on line 52, change the following:             FOR i = 1 TO -r&&

To:              FOR i = 1 TO (-r&& - 1)

That's it!  One little alteration and it works as it should.  This glitch is entirely from my own flawed logic with notations, and has nothing at all to do with QB64.   

1e-1 = 0.1, not .01, as I was thinking it did.

Fixed code is below, for those who simply don't want to alter it themselves:

Code: QB64: [Select]

1. _TITLE "N2S$ testing for a scientific notation remover" 'b+ 2020-09-04
2.  
3. ' looks pretty good except for one little bug
4.  
5. IF 1 THEN ' < 0 to skip section, 1 to run section
6.     n = 1 ' has an odd bug jump -7 to -8 moves right 1 extra 0
7.     FOR i = 0 TO 20
8.         PRINT i, N2S$(STR$(n * 10 ^ -i));
9.         LOCATE CSRLIN, 50: PRINT N2S$(STR$(n * 10 ^ i))
10.     NEXT
11. END IF
12.  
13. IF 0 THEN '  < 0 to skip section, 1 to run section
14.     n## = 1 ' but this OK too
15.     'n## = 27.0123456789 'OK
16.     'n## = (1 / 3) 'OK
17.     FOR i = 0 TO 20
18.         PRINT i, N2S$(STR$(n## * 10 ^ -i));
19.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n## * 10 ^ i))
20.     NEXT
21. END IF
22.  
23. FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~40 LOC)
24.     'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
25.     'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)
26.     t$ = LTRIM$(RTRIM$(EXP$))
27.     IF LEFT$(t$, 1) = "-" OR LEFT$(t$, 1) = "N" THEN sign$ = "-": t$ = MID$(t$, 2)
28.     dp = INSTR(t$, "D+"): dm = INSTR(t$, "D-")
29.     ep = INSTR(t$, "E+"): em = INSTR(t$, "E-")
30.     check1 = SGN(dp) + SGN(dm) + SGN(ep) + SGN(em)
31.     IF check1 < 1 OR check1 > 1 THEN N2S = EXP$: EXIT SUB 'If no scientic notation is found, or if we find more than 1 type, it's not SN!
32.     SELECT CASE l 'l now tells us where the SN starts at.
33.         CASE IS < dp: l = dp
34.         CASE IS < dm: l = dm
35.         CASE IS < ep: l = ep
36.         CASE IS < em: l = em
37.     END SELECT
38.     l$ = LEFT$(t$, l - 1) 'The left of the SN
39.     r$ = MID$(t$, l + 1): r&& = VAL(r$) 'The right of the SN, turned into a workable long
40.     IF INSTR(l$, ".") THEN 'Location of the decimal, if any
41.         IF r&& > 0 THEN
42.             r&& = r&& - LEN(l$) + 2
43.         ELSE
44.             r&& = r&& + 1
45.         END IF
46.         l$ = LEFT$(l$, 1) + MID$(l$, 3)
47.     END IF
48.     SELECT CASE r&&
49.         CASE 0 'what the heck? We solved it already?
50.             'l$ = l$
51.         CASE IS < 0
52.             FOR i = 1 TO (-r&& - 1)
53.                 l$ = "0" + l$
54.             NEXT
55.             l$ = "0." + l$
56.         CASE ELSE
57.             FOR i = 1 TO r&&
58.                 l$ = l$ + "0"
59.             NEXT
60.             l$ = l$
61.     END SELECT
62.     IF sign$ = "" THEN sign$ = " "
63.     N2S$ = sign$ + l$
64. END SUB
65.  

[SMcNeill]

And a version which does a little better keeping formatting looking the same with our results:

Code: QB64: [Select]

1. _TITLE "N2S$ testing for a scientific notation remover" 'b+ 2020-09-04
2.  
3. ' looks pretty good except for one little bug
4.  
5. IF 1 THEN ' < 0 to skip section, 1 to run section
6.     n = 1 ' has an odd bug jump -7 to -8 moves right 1 extra 0
7.     FOR i = 0 TO 20
8.         PRINT i, N2S$(STR$(n * 10 ^ -i));
9.         LOCATE CSRLIN, 50: PRINT N2S$(STR$(n * 10 ^ i))
10.     NEXT
11. END IF
12.  
13. IF 0 THEN '  < 0 to skip section, 1 to run section
14.     n## = 1 ' but this OK too
15.     'n## = 27.0123456789 'OK
16.     'n## = (1 / 3) 'OK
17.     FOR i = 0 TO 20
18.         PRINT i, N2S$(STR$(n## * 10 ^ -i));
19.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n## * 10 ^ i))
20.     NEXT
21. END IF
22.  
23. FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~40 LOC)
24.     'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
25.     'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)
26.     t$ = LTRIM$(RTRIM$(EXP$))
27.     IF LEFT$(t$, 1) = "-" OR LEFT$(t$, 1) = "N" THEN sign$ = "-": t$ = MID$(t$, 2)
28.     dp = INSTR(t$, "D+"): dm = INSTR(t$, "D-")
29.     ep = INSTR(t$, "E+"): em = INSTR(t$, "E-")
30.     check1 = SGN(dp) + SGN(dm) + SGN(ep) + SGN(em)
31.     IF check1 < 1 OR check1 > 1 THEN N2S = EXP$: EXIT SUB 'If no scientic notation is found, or if we find more than 1 type, it's not SN!
32.     SELECT CASE l 'l now tells us where the SN starts at.
33.         CASE IS < dp: l = dp
34.         CASE IS < dm: l = dm
35.         CASE IS < ep: l = ep
36.         CASE IS < em: l = em
37.     END SELECT
38.     l$ = LEFT$(t$, l - 1) 'The left of the SN
39.     r$ = MID$(t$, l + 1): r&& = VAL(r$) 'The right of the SN, turned into a workable long
40.     IF INSTR(l$, ".") THEN 'Location of the decimal, if any
41.         IF r&& > 0 THEN
42.             r&& = r&& - LEN(l$) + 2
43.         ELSE
44.             r&& = r&& + 1
45.         END IF
46.         l$ = LEFT$(l$, 1) + MID$(l$, 3)
47.     END IF
48.     SELECT CASE r&&
49.         CASE 0 'what the heck? We solved it already?
50.             'l$ = l$
51.         CASE IS < 0
52.             FOR i = 1 TO (-r&& - 1)
53.                 l$ = "0" + l$
54.             NEXT
55.             l$ = "." + l$
56.         CASE ELSE
57.             FOR i = 1 TO r&&
58.                 l$ = l$ + "0"
59.             NEXT
60.             l$ = l$
61.     END SELECT
62.     IF sign$ = "" THEN sign$ = " "
63.     N2S$ = sign$ + l$
64. END SUB
65.  

[bplus]

Thanks @SMcNeill

I suspected it had something to do with switching from no notation to notation with the number string coming in.

Funny, you added a space if sign was positive whereas I had trimmed space off before sending the number string back if it didn't have notation in it. :)

[bplus]

@SMcNeill  OK now big problem with floats as input: they are all off by 1 zero in decimals when N2S$ is not just trimming the input string. Before it was just the integer 1 that failed as input but other non float inputs seemed OK.

I have * all outputs when N2S$ only trims the input string

Code: QB64: [Select]

1. _TITLE "N2S$ testing for a scientific notation remover" 'b+ 2020-09-04
2. ' looks pretty good except for one little bug
3. ' 2020-09-06 fixed ? see comment line with this date
4.  
5.  
6. IF 0 THEN ' < 0 to skip section, 1 to run section    2020-09-06 this section looks good!
7.     n = 1 ' has an odd bug jump -7 to -8 moves right 1 extra 0     OK beautiful 2020-09-06!
8.     'n = 0.003 ' 2020-09-06 this looks fine too
9.     'n = 1000 / 3 '2020-09-06 fine!
10.     FOR i = 0 TO 20
11.         PRINT i, N2S$(STR$(n * 10 ^ -i));
12.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n * 10 ^ i))
13.     NEXT
14. END IF
15.  
16. IF 1 THEN '  < 0 to skip section, 1 to run section
17.     n## = 1.0 ' but this OK too (when n=1 wasn't working)   2020-09-06 Now this is wrong!!!
18.     n## = 1000 / 3 'OK                                      and this
19.     n## = .003 'OK                                          and this
20.     FOR i = 0 TO 20
21.         'PRINT i, STR$(n## * 10 ^ -i), N2S$(STR$(n## * 10 ^ -i))
22.         PRINT i, N2S$(STR$(n## * 10 ^ -i));
23.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n## * 10 ^ i))
24.     NEXT
25. END IF
26.  
27. FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~43 LOC)
28.     DIM t$, sign$, L$, R$, r&&
29.     DIM dp AS INTEGER, dm AS INTEGER, ep AS INTEGER, em AS INTEGER, check1 AS INTEGER, L AS INTEGER, i AS INTEGER
30.     'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
31.     'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)
32.     t$ = _TRIM$(EXP$)
33.     IF LEFT$(t$, 1) = "-" OR LEFT$(t$, 1) = "N" THEN sign$ = "-": t$ = MID$(t$, 2)
34.     dp = INSTR(t$, "D+"): dm = INSTR(t$, "D-")
35.     ep = INSTR(t$, "E+"): em = INSTR(t$, "E-")
36.     check1 = SGN(dp) + SGN(dm) + SGN(ep) + SGN(em)
37.     IF check1 < 1 OR check1 > 1 THEN N2S$ = _TRIM$(EXP$) + "*": EXIT SUB 'If no scientic notation is found, or if we find more than 1 type, it's not SN!
38.     SELECT CASE L 'l now tells us where the SN starts at.
39.         CASE IS < dp: L = dp
40.         CASE IS < dm: L = dm
41.         CASE IS < ep: L = ep
42.         CASE IS < em: L = em
43.     END SELECT
44.     L$ = LEFT$(t$, L - 1) 'The left of the SN
45.     R$ = MID$(t$, L + 1): r&& = VAL(R$) 'The right of the SN, turned into a workable long
46.     IF INSTR(L$, ".") THEN 'Location of the decimal, if any
47.         IF r&& > 0 THEN
48.             r&& = r&& - LEN(L$) + 2
49.         ELSE
50.             r&& = r&& + 1
51.         END IF
52.         L$ = LEFT$(L$, 1) + MID$(L$, 3)
53.     END IF
54.     SELECT CASE r&&
55.         CASE 0 'what the heck? We solved it already?
56.             'l$ = l$
57.         CASE IS < 0
58.             FOR i = 1 TO (-r&& - 1) 'fix SMcNeill 2020-09-06
59.                 L$ = "0" + L$
60.             NEXT
61.             L$ = "." + L$ ' 2020-09-06 removed 0 of "0." + L$  to keep consistent with other returns
62.         CASE ELSE
63.             FOR i = 1 TO r&&
64.                 L$ = L$ + "0"
65.             NEXT
66.             L$ = L$
67.     END SELECT
68.     N2S$ = sign$ + L$
69. END SUB
70.  
71.  

It seems if you get the floats correct the integers (or just 1 is off). Fix 1 and all the floats are off.

[bplus]

Sorry @SMcNeill

You had it right the first time!

I finally tracked down the source of the bug. It was in the test, we needed to DIM i as INTEGER for the powers of 10.

Here is the proof:

Code: QB64: [Select]

1. _TITLE "N2S$ testing for a scientific notation remover" 'b+ 2020-09-04
2. ' source of bug tracked down 2020-09-08
3. ' looks pretty good except for one little bug fixed now
4.  
5. 'It was because i was not dim'd as an integer!!!
6. DIM i AS INTEGER '<<<<<<<<<<<<<<<<<<<< Oh man!!!!  this was the problem!!! Discovered 2020-09-08
7.  
8. IF 0 THEN ' < 0 to skip section, 1 to run section
9.     DIM n AS INTEGER '<<<<<<<<<<< comment out to test single
10.     n = 1 ' has an odd bug jump -7 to -8 moves right 1 extra 0   fixed!!
11.     FOR i = 0 TO 20
12.         PRINT i,
13.         LOCATE CSRLIN, 5: PRINT N2S$(STR$(n * 10 ^ -i));
14.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n * 10 ^ i))
15.     NEXT
16. ELSE
17.     BEEP
18.     n## = 1 ' but this OK too
19.     'n## = 27.0123456789 'OK
20.     'n## = (1 / 3) 'OK
21.     FOR i = 0 TO 20
22.         PRINT i;
23.         LOCATE CSRLIN, 5: PRINT N2S$(STR$(n## * 10 ^ -i));
24.         LOCATE CSRLIN, 54: PRINT N2S$(STR$(n## * 10 ^ i))
25.     NEXT
26.     BEEP
27. END IF
28.  
29. FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~40 LOC)
30.     'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
31.     'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)
32.     t$ = LTRIM$(RTRIM$(EXP$))
33.     IF LEFT$(t$, 1) = "-" OR LEFT$(t$, 1) = "N" THEN sign$ = "-": t$ = MID$(t$, 2)
34.     dp = INSTR(t$, "D+"): dm = INSTR(t$, "D-")
35.     ep = INSTR(t$, "E+"): em = INSTR(t$, "E-")
36.     check1 = SGN(dp) + SGN(dm) + SGN(ep) + SGN(em)
37.     IF check1 < 1 OR check1 > 1 THEN N2S = _TRIM$(EXP$): EXIT SUB 'If no scientic notation is found, or if we find more than 1 type, it's not SN!
38.     SELECT CASE l 'l now tells us where the SN starts at.
39.         CASE IS < dp: l = dp
40.         CASE IS < dm: l = dm
41.         CASE IS < ep: l = ep
42.         CASE IS < em: l = em
43.     END SELECT
44.     l$ = LEFT$(t$, l - 1) 'The left of the SN
45.     r$ = MID$(t$, l + 1): r&& = VAL(r$) 'The right of the SN, turned into a workable long
46.     IF INSTR(l$, ".") THEN 'Location of the decimal, if any
47.         IF r&& > 0 THEN
48.             r&& = r&& - LEN(l$) + 2
49.         ELSE
50.             r&& = r&& + 1
51.         END IF
52.         l$ = LEFT$(l$, 1) + MID$(l$, 3)
53.     END IF
54.     SELECT CASE r&&
55.         CASE 0 'what the heck? We solved it already?
56.             'l$ = l$
57.         CASE IS < 0
58.             FOR i = 1 TO -r&&
59.                 l$ = "0" + l$
60.             NEXT
61.             l$ = "." + l$
62.         CASE ELSE
63.             FOR i = 1 TO r&&
64.                 l$ = l$ + "0"
65.             NEXT
66.             l$ = l$
67.     END SELECT
68.     N2S$ = sign$ + l$
69. END SUB
70.  

PS Changes: I am trimming the EXP$ when no exponent is found and I am using .xxxx not 0.xxxx
Among other reasons it makes this test very consistent in output between exponent mods and no exponent mods.

[MWheatley]

Hi.

Where's the original post on this?  Happy to download the code and do some testing.

Malcolm

[bplus]

Hi.

Where's the original post on this?  Happy to download the code and do some testing.

Malcolm

It's listed right with the N2S$ function.

[MWheatley]

I'm sorry: "it's listed right" doesn't mean anything to me.  Where?

Malcolm

[bplus]

I'm sorry: "it's listed right" doesn't mean anything to me.  Where?

Malcolm

"its listed right with the N2S$ function."

What you don't like my demo of the N2S$ Function? ;(

OK here it is highlighted from that function, so you can see it better.


FUNCTION N2S$ (EXP$) 'remove scientific Notation to String (~40 LOC)
    'SMcNeill Jan 7, 2020 ref: https://www.qb64.org/forum/index.php?topic=1555.msg112989#msg112989
    'Last Function in code marked Best Answer (removed debug comments and blank lines added these 2 lines.)