PureBasic Forums - English

Posted: **Mon Feb 21, 2005 1:59 pm**

In every basic language in this world (apart form PB) i found follow simple functions:

Abs(x) - returns the absolute value of a number (for integers)
Swap(x,y) - exchanges the values of the variables
Sign(x) - returns a positive, zero, or negative integer based on the sign of argument

please implement this simple functions. Thanks!

PS: Why not exists a konstant of "PI", like #PI = 3.14159265359?

Posted: **Tue Feb 22, 2005 10:37 am**

#PI = 3.14159265359

Numeric overflow: too big number

Posted: **Tue Feb 22, 2005 10:40 am**

Abs() exists.

Posted: **Tue Feb 22, 2005 10:40 am**

FloHimself wrote:
#PI = 3.14159265359
Numeric overflow: too big number

Not with PB 4.0

Posted: **Tue Feb 22, 2005 12:27 pm**

see your signature!

Posted: **Tue Feb 22, 2005 2:24 pm**

Inner wrote:Abs() exists.

..only for float numbers!!! Read the manual accurately and you see: "This function works correctly only with float numbers. With integer it will fail if the integer is too big (loss of precision). Another function will be added to do that." (http://www.purebasic.com/documentation/index.html)

The label "Abs()" for this function is actual confusing, "AbsF()" is better - like Str() and StrF().

Hehe, sorry for my PI:

Code: Select all

#PI = 3.14159265
Debug #PI

Posted: **Tue Feb 22, 2005 5:48 pm**

Pi=ATan(1)*4

Posted: **Tue Feb 22, 2005 6:10 pm**

Andras wrote:Pi=ATan(1)*4

Code: Select all

pi.f

Pi=ATan(1)*4

Debug pi

- np

Posted: **Tue Feb 22, 2005 6:33 pm**

Lebostein wrote:The label "Abs()" for this function is actual confusing, "AbsF()" is better - like Str() and StrF().

Hehe, sorry for my PI:
Code: Select all
#PI = 3.14159265
Debug #PI

You are right about the syntax incoherence. I second that.

As you can see #PI constant sould be better to be stablished when 64, 80, (and 128) bit floats are available.

Inner wrote:Abs() exists.

Yeah. Just like God. But not for integers, but for fractionated ones.

BTW, shorter:

Code: Select all

Pi=ACos(-1)

Posted: **Tue Feb 22, 2005 7:04 pm**

LOL

Code: Select all

; The result will be output to approximately the number of decimal places requested 
; Initially try 770 decimal places.  The last 8 digits should be 9999 9983 

Declare addbtoa() 
Declare subbfroma() 
Declare divcby25() 
Declare divdby57121() 
Declare divcbyn() 
Declare divdbyn() 

Global d, x, n 

OpenConsole() 
Print("Number of decimal places? ") 
np=Val(Input()) 
If np<4: np=4: EndIf 
PrintN("") 
x=10000 : xw=4 
d=np/xw+2 
; Working registers, each element holding an integer 0..9999 
Dim a(d) 
Dim b(d) 
Dim c(d) 
Dim d(d) 
it=(np/Log10(25)+5)/2 ; Number of iterations 
c(1) = 800 : d(1) = 9560 : n=-1 
For j=1 To it 
  n + 2 
  divcby25() 
  divcbyn() 
  addbtoa() 
  divdby57121() 
  divdbyn() 
  subbfroma() 
  n + 2 
  divcby25() 
  divcbyn() 
  subbfroma() 
  divdby57121() 
  divdbyn() 
  addbtoa() 
Next j 
; Print result 
Print("  3.1") 
For i=2 To d-1 
  Print(RSet(Str(a(i)),xw,"0")+" ") 
  If (i%15)=0 
    PrintN("") 
  EndIf 
Next i 
PrintN("") 
PrintN("Press ENTER") 
Input() 
CloseConsole() 
End 


Procedure addbtoa() ; Multi-precision addition 
  c=0 ; Carry 
  For i=d To 1 Step -1 
    s = a(i)+b(i)+c 
    c = s/x 
    a(i) = s%x 
  Next i 
EndProcedure 

Procedure subbfroma() 
  c = 0 
  For i=d To 1 Step -1 
    s = a(i)-b(i)-c 
    If s<0 
      s + x: c = 1 
    Else 
      c=0 
    EndIf 
    a(i) = s%x 
  Next i 
EndProcedure 

Procedure divcby25() 
  r = 0 ; Remainder 
  For i=1 To d 
    c = c(i)+x*r 
    c(i) = c/25 
    r=c%25 
  Next i 
EndProcedure 

Procedure divdby57121() 
  r = 0 
  For i=1 To d 
    c = d(i)+x*r 
    d(i) = c/57121 
    r=c%57121 
  Next i 
EndProcedure 

Procedure divcbyn() 
  ; b()=c()/n 
  r = 0 
  For i=1 To d 
    c = c(i)+x*r 
    b(i) = c/n 
    r=c%n 
  Next i 
EndProcedure 

Procedure divdbyn() 
  ; b()=d()/n 
  r = 0 
  For i=1 To d 
    c = d(i)+x*r 
    b(i) = c/n 
    r=c%n 
  Next i 
EndProcedure

- np

Posted: **Tue Feb 22, 2005 8:32 pm**

Code: Select all

Procedure AbsL(Value.l)
  If Value < 0 : Value = - Value : EndIf
  ProcedureReturn Value
EndProcedure

Posted: **Wed Feb 23, 2005 8:09 am**

ts-soft wrote:

Code: Select all

Procedure AbsL(Value.l)
  If Value < 0 : Value = - Value : EndIf
  ProcedureReturn Value
EndProcedure

This is a wishlist forum and not a "how i can do...?". My ambition (vision) is a better Basic with all standard functions from the older/other Basics. I don't need this functions this time, I will reduce the work to convert code from other Basics to PB, for example.

These functions are very simple to implement.... I hope against hope

Posted: **Wed Feb 23, 2005 9:21 am**

Lebostein wrote:This is a wishlist forum and not a "how i can do...?". My ambition (vision) is a better Basic with all standard functions from the older/other Basics. I don't need this functions this time, I will reduce the work to convert code from other Basics to PB, for example.

These functions are very simple to implement.... I hope against hope

Well said Lebostein. Great. And I second your ambition for PB too

I think just that, and some other things, is what all the PB comunity member must want and try in order to get a better and better PB.

Posted: **Tue May 13, 2008 9:53 pm**

Now, after 3 years since the last request, I see no change. I am very unhappy and discontented about the situation of the math library in PB! What is the problem to add this simple functions?

:roll:

Posted: **Tue May 13, 2008 10:28 pm**

No need to dig up old posts and tell "man what are you doing here, it's alreay XX years and nothing comes" - it's annoying. This forum is for features request, not things to implement. If you are not happy with our decisions, write your own functions. BTW, 'swap' is here or i miss something ?

PureBasic Forums - English

More simple math functions...

More simple math functions...