Hello,
I am not sure this is a bug but I am struggling with a discrepancy between R16 and etax when using a matrix element.
I am attaching a simple test file below.
In short when I use a mtrix element in a beamline that is generating dispersion I noticed that my dispersion does not match with the R16 computed by the &matrix_output; see mu stdout below.
For this beamline I would expect both value to match. Thanks for any help! -- Philippe.
=====================================================================================
[piot@paris Slits]$ sddsprintout -column=s -column=ElementName -column=etax -column=etay test.twi
Printout for SDDS file test.twi
s ElementName etax etay
m m m
----------------------------------------------------------
0.000000e+00 _BEG_ 0.000000e+00 0.000000e+00
5.000000e-01 D1 0.000000e+00 0.000000e+00
7.920400e-01 DIPOLE1 -5.660879e-02 0.000000e+00
1.292040e+00 D1 -2.529612e-01 0.000000e+00
1.584080e+00 DIPOLE2 -3.016019e-01 0.000000e+00
1.584080e+00 TDC -3.016019e-01 0.000000e+00
2.084080e+00 D2 -3.016019e-01 0.000000e+00
2.374480e+00 SPEC -3.176425e-01 1.082969e-01
3.874480e+00 D3 1.057375e-02 1.350938e+00
[piot@paris Slits]$ sddsprintout -column=s -column=ElementName -column=R16 -column=R36 test.mat
Printout for SDDS file test.mat
s ElementName R16 R36
m m/1 m/1
----------------------------------------------------------
0.000000e+00 _BEG_ 0.000000e+00 0.000000e+00
5.000000e-01 D1 0.000000e+00 0.000000e+00
7.920400e-01 DIPOLE1 -5.660879e-02 0.000000e+00
1.292040e+00 D1 -2.529612e-01 0.000000e+00
1.584080e+00 DIPOLE2 -3.016019e-01 0.000000e+00
1.584080e+00 TDC -2.530818e-01 0.000000e+00
2.084080e+00 D2 -9.129789e-02 0.000000e+00
2.374480e+00 SPEC -2.189457e-03 1.269738e-02
3.874480e+00 D3 4.609148e-01 1.583921e-01
------ test.ele file
problem (bug?) with matrix calculation
Moderators: michael_borland, soliday
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problem (bug?) with matrix calculation
- Attachments
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- CavOnMatrix.txt
- matrix file used in the lattice file
- (395 Bytes) Downloaded 791 times
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- test.ele
- command file
- (861 Bytes) Downloaded 836 times
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Re: problem (bug?) with matrix calculation
Philippe,
This is a bug. The matrix computation is correct but the twiss parameter propagation is not in this particular case.
The problem is that the twiss parameter computation ignores the time coordinate. I'm looking into how to fix it.
--Michael
This is a bug. The matrix computation is correct but the twiss parameter propagation is not in this particular case.
The problem is that the twiss parameter computation ignores the time coordinate. I'm looking into how to fix it.
--Michael
-
- Posts: 1945
- Joined: 19 May 2008, 09:33
- Location: Argonne National Laboratory
- Contact:
Re: problem (bug?) with matrix calculation
This was fixed in release 23.1.0. The "local_dispersion" control of twiss_output can be used to change the default behavior. See the manual for details.
--Michael
--Michael