Hey, sorry, no - you're right - I just made up that number on the fly,
because I didn't have the actual output handy.
This is the kind of output with the arbitrary values that I get sometimes:
["c_c", (8.643714722839287e-6*(2313820*%r18^2*%e^(20*%r19)-1416)
-20*%r18^2*%e^(20*%r19)+0.0122395) ^2,
[.001111111111111111*(1000*%r18^2*%e^(1000*%r19)-100*%r18^2*%e^(100*%r19)),
((450000*%r18^2*%r19^2-1000*%r18^2*%r19+%r18^2)*%e^(1000*%r19)
+(45000*%r18^2*%r19^2+100*%r18^2*%r19-%r18^2)*%e^(100*%r19))
/%r19^2], "\"[[a = %r18,b = %r19,c =
-8.643714722839287e-6*(2313820*%r18^2*%e^(20*%r19)-1416)]]\""]
Here I am trying to fit this:
y = a^2 * x * exp(b * x) + c
using lsquares, with the parameters being guessed indicated as [a, b, c].
In this case, you can see the parameter array guessed by lsquares:
[[a = %r18,b = %r19,c =
-8.643714722839287e-6*(2313820*%r18^2*%e^(20*%r19)-1416)]]
and also the error calculated by lsquares for that specific fit:
(8.643714722839287e-6*(2313820*%r18^2*%e^(20*%r19)-1416)
-20*%r18^2*%e^(20*%r19)+0.0122395) ^2
and then an integral counted using the fit: it's basically the area
between the function's graph - let's say f(x), between x=100, x=1000,
and a straight line which goes from f(100) to f(1000). Also the slope
of the mentioned straight line is put out. The integral is:
((450000*%r18^2*%r19^2-1000*%r18^2*%r19+%r18^2)*%e^(1000*%r19)
+(45000*%r18^2*%r19^2+100*%r18^2*%r19-%r18^2)*%e^(100*%r19))
/%r19^2
and the slope is:
.001111111111111111*(1000*%r18^2*%e^(1000*%r19)-100*%r18^2*%e^(100*%r19))
Does this help any further?
I get this sort of error from many fits that I run; I'm not sure where
to go with this.
On Thu, Nov 10, 2011 at 15:35, Richard Fateman
<fateman at eecs.berkeley.edu> wrote:
> On 11/10/2011 6:22 AM, cheater cheater wrote:
>>
>> Hi again, I have noticed that a lot of people post this info
>
> ...
>
> It would probably be more useful if you indicated what program you were
> running.
> In particular, if your output truly includes ?3^2, ?rather than 9, ?perhaps
> you have turned
> off simplification, in which case many programs will not operate normally.
>
> It could be that ?using values like 1.0 ? ? rather than 1 ? ? will help, but
> that is just a guess.
>
>