caps complex tests



I just realized you defined PRI in a previous email on this thread.  Since 
it is not clear what x is in the case of radcan(sqrt(y^2-2*y+1)) then when 
you apply the PRI you get y-1.
It is good to have flags like radexpand too.  You have to have more than one 
algorithm for simplification since different problems might require a 
different answer.  I don't think integrate(sqrt(1-2*y+y^2),x) can have just 
one right answer.

I don't know if I should change pw.mac to handle this case.  It's probably a 
bad idea.  I have to think about it.

pwint(sqrt(1-2*y+y^2),x)=?

Rich



-----Original Message----- 
From: Richard Hennessy
Sent: Sunday, November 14, 2010 8:34 PM
To: Richard Fateman
Cc: Richard Fateman ; Maxima - list
Subject: Re: [Maxima] caps complex tests

I downloaded you paper yesterday.  It does not define "positive real
interpretation" but it refers to it.  Is there a precise definition of PRI
that will not cost me another chunk of change to download?

Rich

-----Original Message----- 
From: Richard Fateman
Sent: Sunday, November 14, 2010 8:24 PM
To: Richard Hennessy
Cc: Richard Fateman ; Maxima - list
Subject: Re: [Maxima] caps complex tests

On 11/14/2010 4:59 PM, Richard Hennessy wrote:
> Speaking of interpretation. radcan(sqrt(y^2-2*y+1)) is using sqrt(x^2)=x 
> so you get y-1.  Well, why not 1-y instead as your example below points 
> out?
>
> radcan(sqrt(y^2-2*y+1));
> -> y-1
>
There is one answer which corresponds to PRI (positive real
interpretation), which is y-1.
That is what radcan is supposed to return.

It does NOT return 1-y   for sqrt((1-y)^2).

because that is not the PRI.     y-1 is.

RJF




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