Re: Decimal exponent (power) in i4gl?

Here's a tiny c power function for use with 4gl: #include <math.h> #include <stdio.h> power(nargs) int nargs; { double x,y; popdub(&y); popdub(&x); x = pow(x,y); retdub(&x); return(1); } You have to link it to the 4gl runner (or c4gl program) as the manuals describe. 4gl usage would be "let z = power(x,y)". Peter Lancashire wrote: > > Manuel A. Daponte Santiago wrote: > > > > In i4gl there is the ** operand to raise a number to a power, but it > > only handles integers (2 ** 2.5 = 4). > > > > Does somebody know hot to perform this operation? > > > > Thanks in advance > > The database engine from version 7.1 can do it (extract from manual): > > POW Function > > The POW function raises the base to the exponent. This function requires > two numeric arguments. The return type is FLOAT. The following example > returns all the information for circles whose areas ( p r 2 ) are less > than 1,000 square units: > > SELECT * FROM circles WHERE (3.1417 * POW(radius,2)) < 1000> > 4GL (pre 7.?) will probably not recognise this, so you will have to > PREPARE the statement. > > If you don't have 7.1+ then you will have to write a C function to call > from 4GL. This is not difficult if you know C and read the manual. It's > slightly trickier for RDS as you have to compile a custom runner. > -- > Peter Lancashire > Information Systems Specialist, Bayer plc > Eastern Way, Bury St Edmunds, Suffolk, IP32 7AH, UK > Tel: +44-1635-562258, Fax: +44-1635-562281 > --- > If all else fails, read the instructions AND the release notes. > All opinions are my own and not those of Bayer plc. > My Internet plumbing does not allow me to mail and post news together. > Sorry. > --- > Join Infuse, the UK Informix User Group at http://www.infuse.org.uk/ -- ---------------------------------------------------------------------- John H. Frantz Power-4gl: Extending Informix-4gl john@rl.is http://www.rl.is/~john/pow4gl.html