FUNCTION USING()

[Walt Decker]

Without invoking Liberty Basic's USING() function, huge values of the integer number subset can be displayed. However, only up to 8 digits can be displayed when the decimal number set is used. As the number of integer digits increase the number of decimal digits decrease. At eight integer digits, only one decimal digit can be displayed. At nine integer digits, Liberty Basic converts the decimal number to scientific notation. At this point one can use the USING() function to accurately display the number with an accuracy of up to six decimal digits. Beyond six decimal digits the remaining digits are not accurate. This may be a quirk of the computer binary number system.

The following code displays this and uses the Liberty Basic USING() function to format the numbers so that they may be displayed with decimal points aligned and the hundreds fields separated with a comma.

'
DIM Numbers(6)

Numbers(0) = 10919635748.69798564
Numbers(1) = -10653785
Numbers(2) = 1976.42
Numbers(3) = -19074252.83882
Numbers(4) = 1.96375893184
Numbers(5) = -100
Numbers(6) = 5107196357482
MaxLen = -999
FOR I = 0 TO 6
 NumStr$ = STR$(Numbers(I))
 print NumStr$
 IF INSTR(UPPER$(NumStr$), "E") THEN '<--- number as scientific notation
   NumStr$ = USING("####################.#########", Numbers(I))'<--- translate
                                                                'to a string
   NumStr$ = TRIM$(NumStr$) '<--- remove leading and trailing white space
 END IF

'<--------- extract the integer part -------->
 Dot = INSTR(NumStr$, ".")
 IF Dot = 0 THEN
   Lft$ = NumStr$
 ELSE
  Lft$ = LEFT$(NumStr$, Dot - 1)
 END IF

 IF LEFT$(Lft$, 1) = "-" THEN '<--- remove negative sign
   Lft$ = MID$(Lft$, 2)
 END IF

 MaxLen = MAX(MaxLen, LEN(Lft$)) '<--- find the maximum lenght of the numeric
                                 'group

 NumGroups = MAX(NumGroups, INT(LEN(Lft$) / 3)) '<--- find maximum number of
                                                '100s groups
NEXT I

MaxLen = MaxLen + NumGroups + 1 '<--- add max length and max 100s groups
                               'together plus one for possible negativ
                               'number
FOR I = 0 TO 6
 NumStr$ = FN.Fmt$(Numbers(I), ",", " ", MaxLen) '<--- format the numbers so
                                                 'that decimals will align.
                                                 'The integer number set has
                                                 'an implied decimal value of
                                                 'zero
 PRINT NumStr$
NEXT I

END

'------------------------------------------------------
'------------------------------------------------------

FUNCTION FN.REPEAT$(StrIn$, Ntimes)
'############################################
'  CREATE A STRING Ntimes
'############################################

I = 0
StrOut$ = ""

FOR I = 1 TO Ntimes
 StrOut$ = StrOut$ + StrIn$
NEXT I

FN.REPEAT$ = StrOut$
END FUNCTION

'----------------------------------------------------
'----------------------------------------------------

FUNCTION FN.Fmt$(Number, MidDlm$, PadStr$, MaxLen)

NumStr$ = ""  '<--- translate "Number" to a string
IntStr$ = ""  '<--- integer part of number
DecStr$ = ""  '<--- decimal part of number
Minus$  = "-" '<--- negative number indicator

I = 0   '<--- counter
Dot = 0 '<--- decimal point position

Hundreds = 0 '<--- # of 100's
Remain   = 0 '<--- part of integer that is not 100
Padding  = 0 '<--- how much to add to string

NumStr$ = STR$(Number) '<--- translate number to string
IF INSTR(UPPER$(NumStr$), "E") THEN '<--- check for scientific notation
 NumStr$ = USING("####################.#########", Number) '<--- reformat
 NumStr$ = TRIM$(NumStr$) '<--- remove white space
END IF

Dot = INSTR(NumStr$, ".") '<--- find decimal point

''<------- extract integer and decimal parts ----->
IF Dot = 0 THEN
 IntStr$ = NumStr$
ELSE
 IntStr$ = LEFT$(NumStr$, Dot - 1)
 DecStr$ = MID$(NumStr$, Dot)
END IF

IF LEFT$(IntStr$, 1) = Minus$ THEN '<--- is number negative
 IntStr$ = MID$(IntStr$, 2) '<--- remove negative sign

 Padding = MaxLen - LEN(IntStr$) '<how much padding is needed

'<--- determine type of padding to use ------->
 IF PadStr$ = "0" THEN
   Padding = Padding - 3
   IntStr$ = (FN.REPEAT$(PadStr$, Padding) + IntStr$)
 END IF

 Hundreds = INT(LEN(IntStr$) / 3) '<--- number of 100s groups
 Remain = LEN(IntStr$) - Hundreds * 3 '<--- not 100s group

 IF Remain THEN
   IF LEN(IntStr$) <= 3 THEN  '<--- one 100s group
     Remain = LEN(IntStr$) + 1
   ELSE '<--- more than one 100s group
     IntStr$ = LEFT$(IntStr$, Remain) + MidDlm$ + MID$(IntStr$, Remain + 1)
     Remain = Remain + 3 + 1
   END IF
 ELSE
   Remain = 3
 END IF

 FOR I = 1 TO Hundreds
   IF Remain >= LEN(IntStr$) THEN EXIT FOR

   IntStr$ = LEFT$(IntStr$, Remain) + MidDlm$ + MID$(IntStr$, Remain + 1)

   Remain = Remain + 3 + 1 '<--- location of next 100s group
 NEXT I

 IF PadStr$ <> "0" THEN  '<--- add front padding
   IntStr$ = Minus$ + IntStr$
   Padding = MaxLen - LEN(IntStr$)
   IntStr$ = (FN.REPEAT$(" ", Padding) + IntStr$)
 ELSE
   IntStr$ = Minus$ + IntStr$
 END IF

 IF DecStr$ = "" THEN
   NumStr$ = IntStr$
 ELSE
   NumStr$ = IntStr$ + DecStr$
 END IF
 FN.Fmt$ = NumStr$
 EXIT FUNCTION
END IF

Padding = MaxLen - LEN(IntStr$)

IF PadStr$ = "0" THEN
 Padding = Padding - 3
 IntStr$ = (FN.REPEAT$(PadStr$, Padding) + IntStr$)
END IF

Hundreds = INT(LEN(IntStr$) / 3)
Remain = LEN(IntStr$) - Hundreds * 3

IF Remain THEN
 IF LEN(IntStr$) <= 3 THEN
   Remain = LEN(IntStr$) + 1
 ELSE
   IntStr$ = LEFT$(IntStr$, Remain) + MidDlm$ + MID$(IntStr$, Remain + 1)
   Remain = Remain + 3 + 1' + Padding
 END IF
ELSE
 Remain = 3
END IF

FOR I = 1 TO Hundreds
 IF Remain >= LEN(IntStr$) THEN EXIT FOR

 IntStr$ = LEFT$(IntStr$, Remain) + MidDlm$ + MID$(IntStr$, Remain + 1)

 Remain = Remain + 3 + 1
NEXT I

IF PadStr$ <> "0" THEN
 Padding = MaxLen - LEN(IntStr$)
 IntStr$ = (FN.REPEAT$(" ", Padding) + IntStr$)
ELSE
 IntStr$ = " " + IntStr$
END IF

NumStr$ = IntStr$ + DecStr$
FN.Fmt$ = NumStr$

END FUNCTION
'