| T O P I C R E V I E W |
| athoba |
Posted - 07/22/2010 : 10:41:00 AM
Origin Ver. and Service Release (Select Help-->About Origin): origin 7 SR 2
Operating System: wind xp
Hello everybody,
I realy need help
since 2 weeks I am trying to use this function:
y=(298.4/1+((1.4-x+P1)-((1.4-x+P1)*(1.4-x+P1)+4*x*P2)^1/2)/P1)-100.8((1.4-x+P1)-((1.4-x+P1)*(1.4-x+P1)+4*x*P1)^1/2))+811.3*P2)/(175.5/1+(1.4-x+P1)-((1.4-x+P1)*(1.4-x+P1)+4*x*P1)^1/2)/P1)-53((1.4-x+P1)-((1.4-x+P1)*(1.4-x+P1)+4*x*P1)^1/2))+312*P2);
to fit this data
C/ mM Hydrodynamic Radius/ nm
0 1.7
0.055 1.8
0.11 1.88
0.21 1.98
0.29 2.29
0.55 2.65
0.75 2.67
0.89 2.69
1 2.68
1.13 2.72
1.2 2.71
1.26 2.72
1.36 2.75
Every time I got this message: Unable to compile user defined function
I opened a new workspace and loaded the function then I tried to compile it but I got this Errors
compiling...
_nlfyath2.fit
C:\Programme\OriginLab\Origin7\OriginC\NLSF\_nlfyath2.fit(23) :Error, invalid term
C:\Programme\OriginLab\Origin7\OriginC\NLSF\_nlfyath2.fit(23) :Error, general compile error
C:\Programme\OriginLab\Origin7\OriginC\NLSF\_nlfyath2.fit(14) :Error, error(s) found in compiling function _nlsfyath2
Sincerely Yours |
| 3 L A T E S T R E P L I E S (Newest First) |
| athoba |
Posted - 07/23/2010 : 12:53:14 PM
Hello Anguilla and one moment, still I have this error: "28037, possibly error in formula or poorly initialized parameters",
What shall I do , scape or give up, I am writing my thesis I want to finish 
This equation I devolped it from dynamic light scattering equations
to get the association constant and the concentration of the species? BUT
what shall I do??
Sincerely Yours |
| athoba |
Posted - 07/22/2010 : 5:41:34 PM
 Danke gerg . It is working now 
but the fit results sounds strange. Any way I will come back if it is not working
Sincerely Yours |
| greg |
Posted - 07/22/2010 : 1:33:28 PM
Your first problem is that you cannot use implicit multiplication, so you must replace
-100.8((
with
-100.8*((
and
53((
with
53*((
unless you need addition or subtraction here.
The remaining problem is a parity error with your parentheses. Adding five more '(' to the beginning of the equation compiles, but I have no idea what you intended. |
