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Phi-beta fit
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functions
Two solutions of quadratic equation in ARC region
- POS: y = -B + sqrt(B*B-C)
- NEG: y = -B - sqrt(B*B-C)
Arc region
pyimgalgos/src/FiberAngles.py
y = funcy_l1_v1(x, phi_deg, bet_deg, DoR=392390/913.27, sgnrt=-1.)
Two solutions of quadratic equation
- POS: y = -B + sqrt(B*B-C)
- NEG: y = -B - sqrt(B*B-C)
Legend:
- dot curves for negative beta
- black bold curve for beta=0
- solid curves for positive beta
Arc region
# or ... sgnrt=-1.)
wide range of x:
narrow range of x:
Equatorial region
- For POS root: beta=-13.3 gives minimal y.
- If two measured peaks are located below this curve then B*B-C < 0, fit returns limit value of beta or not converging.
- Two solutions for beta -17 and -9 - x and y are the same.
- NEG-ative root gives wrong curvature
Equatorial region
pyimgalgos/src/FiberAngles.py
y = funcy_l0(x, phi_deg, bet_deg)
Problem with two roots is resolved for EQU region; sign of the root is selected the same as sign of parameter B;
...
- For |beta|>~48 solution does not exist for entire range of x
Data
exp=cxif5315:run=169
Fit in the processing script
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Phi-beta fit results and quality
Data: peak list selected by Meng
- exp=cxif5315:run=169
- Distribution of parameters for peaks selected by Meng:
EQU region
ARC region: 1-st solution for beta (positive root)
ARC region: 2-nd solution for beta (positive root)
For 2-peak events fit does not have any freedom - curve can exactly be fitted to 3 points (including origin); chi2=0 and probability is always 1.
For >2-peak events chi2 and probability show some distribution.
Data: peak list after pfv2r1
EQU region
ARC region
Peak list with phi-beta fit results
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... fit-phi fit-beta phi-err beta-err fit-chi2 ndof fit-prob ... 1.30 -42.98 3.800454 10.236941 0.000000 1 1.000000 ... -4.75 -23.85 0.265462 1.212093 1.734365 3 0.629321 |
| Note |
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If someone want to To load this file using use helper classes |
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