# Set fit parameters limits can get so different result?

i fit a 2dgraph ,i found : if i don’t set parmeters limits ,i can not get results.
but when i set parmeters limits ,and even a small change of the limits ,the results change greatly.
for example:

```fit->SetParLimits(i,-11000,11000); ```
chang into :

``` fit->SetParLimits(i,-10000,10000);```
all_diff_data.txt (3.81 KB)
fit2Dg_of_diff.c (4.14 KB)

Hi,