Originally Posted by: Jean Giraud 
There has to be a program mistake somewhere?
Jan,
Let's make it clear: the program as you wrote regarding the project calculations,
you are the only expert, maybe the unit system make some big coefficients.
If you mean
program mistake as Smath, there is no error, let me explain.
Two types of error were reported:
1. "input string was not in correct order" => this is a Win error message, what does it mean ?
In the symbolic expansion some elements are of the form "Power function" [X^Y]
This X^Y is built-in in Win and does not take those very high coefficients.
There is NOTHING to cure/rescue Win.
2. The other error "result is above max allowed" => this is an Smath error message, what it means ?
In the symbolic expansion, some of the coefficients are immensly long, they look 64 bits expansion
from which "Smath symbolic engine code" ??? Thus, Smath 32 bits can't process.
I say that from other problems encountered In Smath "result is above max allowed"
Smath does an extraordinary good job about Thiele fit methods. After the symbolic expansion,
some coefficients appear as fractions of so long num/den. For practical works and export a "formula"
we have to reduce these long num/den as simple number, thus simply copy the immense num/den
and equate to get a number. Generally it did work, when the num/den can be evaluated 32 bits.
I have encountered some num/den to immense [presumably 64 bits] with the error message
"result above max allowed" ... I found some reconciliation to these error message.
Unfortunately=> not yet wrt your project. I will revisit, but in the mean time if Smath
can't process the numerical coefficients => it can't process the derivative.
Simply deceptive but most interesting.
Smath has its own symbolic engine, that's what you see when you hover a function.
But when you command for the symbolic expansion [Ctrl+.] it seems to expand from
Maple symbolic, thus the 64 bits expansion.
Jean
