**HP Prime: Base Conversions – Joe Horn**

Special thanks
to Joe Horn. When I posted the
conversion programs ( http://edspi31415.blogspot.com/2017/02/hp-prime-and-ti-84-plus-ce-convert.html
), Horn alerted me to a hidden convert command where we can convert base
integers.

The HP Prime
has a CONVERT (upper case letters) that converts units (i.e. length, volume,
etc.). However, for the base to work,
not only convert has to be typed in lower case letters, AND it is a CAS
command.

The syntax that
Joe told me is:

**Decimal to Other Base (D2B)**

convert(

*number in base 10*,**base**,*desired base*)
The word base
is typed in lowercase. The result is a
vector of digits but the order goes from lower power to upper power. The number will be written backwards. To get it in proper order:

REVERSE(convert(

*number in base 10*,**base**,*desired base*))
In Home mode or
in programming, you will need a CAS command attached to the syntax.

**Other Base to Decimal**

convert(

*vector of digits*,**base**,*base that is represented*)
Again, going
this way the vector of digits goes from lower to upper power. The proper order requires the following:

convert(REVERSE(

*vector of digits*),**base**,*base that is represented*)
Once again, in
Home mode or in programming, you will need a CAS command attached to the
syntax.

Below are
programs that help accomplish these tasks:

**HP Prime Program D2B (decimal to base)**

EXPORT D2B(n,b)

BEGIN

// decimal to base

// Joe Horn

CAS("REVERSE(convert(n,base,b))");

END;

Example: D2B(17291, 12) returns [10 0 0 11] (A00B_12)

**HP Prime Program B2D (base to decimal)**

EXPORT B2D(n,b)

BEGIN

// vector (decr),base to base 10

// Joe Horn

CAS("convert(REVERSE(n),base,b)");

END;

Example: B2D([1, 0, 1, 6, 2, 5], 7) returns
17463. (101625_7)

Thank you Joe! As Joe Horn always says, Happy Programming!

Eddie

This blog is property of Edward
Shore, 2017.

See the profiles of experts named Eddie Choufi on twitter. There are 3 experts named Eddie Choufi, who utilize twitter to trade data. See what Eddie choufi (eddiechoufi) has found on twitter, the world's greatest gathering of the loved and admired things.

ReplyDeleteHi, I added a bit to render the output more readable aka useful.

ReplyDeleteSee below :

EXPORT Dec2Base(n,b)

BEGIN

LOCAL r := iPart(ROUND(n,0));

RETURN CAS("char(apply((x)->PIECEWISE(10>x,x+48,x≥10,x+55),REVERSE(convert(r,base,b))))");

END;

EXPORT Base2Dec(n,b)

BEGIN

RETURN CAS("convert(apply((x)->PIECEWISE(58>x,x-48,x≥58,x-55),REVERSE(ASC(n))),base,b)");

END;

I guess, it could be improved further. Cheers