Get length of a LONG?

eagletalontim

If I have a LONG that totals 12345, how can I get the length of the LONG which would be 5? I am trying to clear the characters after the number is display on an LCD without clearing all the spaces. Sometimes the length will be 2 numbers, sometimes it will be 5 numbers.

Phil Pilgrim (PhiPi)

Using Simple_Numbers.spin as num:

length := strsize(num.dec(your_long))

-Phil

Ariba

Or include a little subroutine like this:

PRI DecSize(value) : n
  repeat
    n++
  until (value/=10) < 1

(not tested)

length := DecSize(myLong)

Andy

JonnyMac

Another possibility, though not as trim or sexy as what's been suggested:

pub digits(value)

  case value
    0..9       : return 1
    10..99     : return 2
    100..999   : return 3
    1000..9999 : return 4
    other      : return 5

For numbers, I like to right-justify in displayed. I have this bit of code in my serial and LCD objects:

pub rjdec(val, width, pchar) | tmpval, pad

'' Print right-justified decimal value
'' -- val is value to print
'' -- width is width of (padded) field for value
'' -- pchar is [leading] pad character (usually "0" or " ")

'  Original code by Dave Hein
'  Added (with modifications) to FDS by Jon McPhalen

  if (val => 0)                                                                 ' if positive
    tmpval := val                                                               '  copy value
    pad := width - 1                                                            '  make room for 1 digit
  else
    if (val == negx)                                                            '  if max negative
      tmpval := posx                                                            '    use max positive for width
    else                                                                        '  else
      tmpval := -val                                                            '    make positive
    pad := width - 2                                                            '  make room for sign and 1 digit
   
  repeat while (tmpval => 10)                                                   ' adjust pad for value width > 1
    pad--
    tmpval /= 10
     
  repeat pad                                                                    ' print pad
    tx(pchar)

  dec(val)                                                                      ' print value

Beau Schwabe

Too bad there isn't a ... LOG(10) function

Phil Pilgrim (PhiPi)

Beau Schwabe wrote:

Too bad there isn't a ... LOG(10) function

It could be done that way:

log₁₀(x) = log₂(x) / log₂(10)

But after the ROM table lookups, interpolations, and division, I wouldn't trust it to be accurate near the power-of-ten boundaries.

-Phil

Peter Jakacki

eagletalontim wrote: »

If I have a LONG that totals 12345, how can I get the length of the LONG which would be 5? I am trying to clear the characters after the number is display on an LCD without clearing all the spaces. Sometimes the length will be 2 numbers, sometimes it will be 5 numbers.

Sometimes those digits mean something such as 000 where it would be important to know that 3 digits were entered. If this number being displayed is a keypad entry then simply count each digit as it is entered. The other thing is that I am a bit worried about is that you are so worried about clearing the number on the LCD in such a precise manner, what is the problem with clearing 5 digits all the time?
The problem of course with all out answers is that the question in couched in such a narrow context which can only mean a narrow answer, which might just miss the mark.