# Cyclic symmetry ngraph=2 corrupted results file for restart frequency analysis

**URL:** <https://calculix.discourse.group/t/cyclic-symmetry-ngraph-2-corrupted-results-file-for-restart-frequency-analysis/4141>\
**Category:** Analysis issues\
**Created:** [October 8, 2026, 12:19pm UTC](https://calculix.discourse.group/t/cyclic-symmetry-ngraph-2-corrupted-results-file-for-restart-frequency-analysis/4141 "2026-10-08T12:19:44Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![linth](https://avatars.discourse-cdn.com/v4/letter/l/898d66/32.png) [@linth](https://calculix.discourse.group/u/linth)\
**Post date:** [October 8, 2026, 12:19pm UTC](https://calculix.discourse.group/t/cyclic-symmetry-ngraph-2-corrupted-results-file-for-restart-frequency-analysis/4141/1 "2026-10-08T12:19:44Z")

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When running a frequency analysis (perturbation) for a cyclic symmetry model and NGRAPH=2 from a restart point, the frd file does not get the results for the second sector but shows NAN at the second sector nodal results. Running the same frequency step after the static step from one input gives meaningful results for the second sector. The calculated frequencies and the results for the 1st sector match for both.

Snippet from the input file with both static and frequency step:

\*Tie, Name=cycsym, Position tolerance=0.05, Adjust=No, cyclic symmetry  
csym\_h, csym\_l  
\*CYCLIC SYMMETRY MODEL, N=50, tie=cycsym, NGRAPH=2  
0,0,0,1,0,0

\*Step, Nlgeom, Inc=100

\*Static  
1.0, 1, 1E-05, 1.0  
\*Boundary, op=New  
\*Boundary  
d\_axial, 3, 3, 0  
\*Boundary  
d\_tang, 2, 2, 0  
\*Dload  
Internal\_Selection-1\_Centrifugal\_Load-1, CENTRIF, 112000, 0, 0, 0, 1, 0, 0  
\*Node file  
RF, U  
\*El file  
S, E, NOE  
\*Contact file  
CDIS, CSTR  
\*end step  
\*Step, Perturbation  
\*restart,write,frequency=0  
\*Frequency  
2  
\*select cyclic symmetry modes, nmin=4, nmax=4  
\*Node file  
U  
\*el file  
\*contact file  
\*End step

Input for restart analysis:

\*restart,read,step=1  
\*Step, Perturbation  
\*restart,write,frequency=0  
\*Frequency  
2  
\*select cyclic symmetry modes, nmin=4, nmax=4  
\*Node file  
U  
\*El file  
\*Contact file  
\*End step

Difference in frd files:

Static + frequency step:

 ![image](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/3/398c39c18f6cbed19ac61c32ed3bc6b5ae90bff0.png)

restart + frequency step:

 ![image](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/c/ce72913bdc318c9423127e43179658753c22a631.png)

Any thoughts on that? I already checked that NGRPAH is read by restartread.f:

 ![image](https://global.discourse-cdn.com/free1/uploads/calculix/original/2X/e/e891d0732597cc8056435cb607f0ca1e7980c282.png)

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<div class="post-metadata">

**Author:** ![fgr](https://avatars.discourse-cdn.com/v4/letter/f/f4b2a3/32.png) [@fgr](https://calculix.discourse.group/u/fgr)\
**Post date:** [October 9, 2026, 5:53am UTC](https://calculix.discourse.group/t/cyclic-symmetry-ngraph-2-corrupted-results-file-for-restart-frequency-analysis/4141/2 "2026-10-09T05:53:37Z")

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@linth it seems to be a bug in ccx\_2.23.

A quick workaround could be to use ccx\_2.22 or older instead of ccx\_2.23

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<div class="post-metadata">

**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\
**Post date:** [October 9, 2026, 7:23am UTC](https://calculix.discourse.group/t/cyclic-symmetry-ngraph-2-corrupted-results-file-for-restart-frequency-analysis/4141/3 "2026-10-09T07:23:55Z")

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@linth Can you report this regression here: [Issues · Dhondtguido/CalculiX · GitHub](https://github.com/Dhondtguido/CalculiX/issues)?