From: mopthisandthat@... (Phidippus)
Date: 2004-04-04T01:49:23+09:00
Subject: Re: error handling

I'm having hard time pinpointing where the error is generated since
there are so many places sqrt are used...

mopthisandthat@hotmail.com (Phidippus) wrote in message news:<a2208ca9.0404010824.65538f9e@posting.google.com>...
> I'm evaluating a function at various values in a for loop. The
> function works most of the times (99% of parameter range I am
> investigating), but at some values, it gives error like below and
> crushes. I guess something wrong with sqrt function. I'm not going to
> attempt to show the function here because it is 1.5Mb. If I evaluate
> the exact same function in Maple at the value it crushed in Ruby, it
> behaves fine.
> 
> Is there any way that when the (sqrt) function crushes, it gives some
> sort of error value and go on to evaluating at the next value without
> crushing the program? I don't want to manually restart the program at
> the next value each time the program crushes. In R, there is "try"
> function that can used for this kind of situation.
> 
> Thank you.
> 
> #####
> /usr/lib/ruby/1.6/complex.rb:82:in `initialize': stack level too deep
> (SystemStackError)
>         from /usr/lib/ruby/1.6/complex.rb:63:in `new'
>         from /usr/lib/ruby/1.6/complex.rb:63:in `Complex'
>         from /usr/lib/ruby/1.6/complex.rb:130:in `/'
>         from /usr/lib/ruby/1.6/mathn.rb:244:in `sqrt'
>         from /usr/lib/ruby/1.6/mathn.rb:244:in `sqrt'
>         from /usr/lib/ruby/1.6/mathn.rb:244:in `sqrt'
>         from /usr/lib/ruby/1.6/mathn.rb:244:in `sqrt'
>         from /usr/lib/ruby/1.6/mathn.rb:244:in `sqrt'
>          ... 1461 levels...
>         from rubyHopf0.rb:17:in `each'
>         from rubyHopf0.rb:17
>         from rubyHopf0.rb:16:in `each'
>         from rubyHopf0.rb:16