How to determine the coefficient of determination for Guinier Fits in Primus?

[franke-biosaxs]

On 2024-01-28 02:31:52, user sammahdi wrote:

Hello,

I'm trying to find the results of my Guinier region. I noticed running the "Radius of Gyration" tab will run Autorg and do a Guinier analysis providing your radius of gyration. While I can see the fit, I cannot see the coefficient of determination for said fit in this window (i.e. R2). Furthermore, there is a difference in the Rg reported in the "Properties" window and the Rg from AutoRg. Why is this the case and which one should be used (I have attached a linke to a photo showing the 34.88 from AutoRg vs. the 34.81 in the Properties window)?

https://imgur.com/a/Bhdg9wR

[franke-biosaxs]

On 2024-01-31 13:08:44, user AL wrote:

sammahdi wrote

While I can see the fit, I cannot see the coefficient of determination for said fit in this window (i.e. R2).

AUTORG and PRIMUS do not calculate the coefficient of determination.

sammahdi wrote

Furthermore, there is a difference in the Rg reported in the "Properties" window and the Rg from AutoRg. Why is this the case and which one should be used (I have attached a linke to a photo showing the 34.88 from AutoRg vs. the 34.81 in the Properties window)?

The "Properties" window shows the meta information from the .dat file header/footer. Probably there was an automated data analysis pipeline that ran AUTORG (with settings different from what PRIMUS is using) and wrote the R _g value of 34.81 Å to the file footer. This value was calculated from an interval different from your points 8-47 where you got 34.88 Å. Please note that the difference of 0.07 Å is negligible by any means.

[franke-biosaxs]

On 2024-01-31 21:02:20, user sammahdi wrote:

Oh ok, thank you!