How to calculate TWISS for a ring

[Landau1908]

Hi, Thomas

How to calculate TWISS for a ring. My code can't work as follows. The plain Madx file COD_HIMM.txt can work very well under Madx program.

from cpymad.madx import Madx
madx = Madx(command_log="HIMM_log.madx")
print(madx.version) 
madx.command.call(file="COD_HIMM.txt")
#calculate TWISS
twiss0 = madx.twiss(sequence='COD_HIMM.txt')

error occured:

twiss0 = madx.twiss(sequence='COD_HIMM.txt')
Traceback (most recent call last):

  File "<ipython-input-89-95502ed45d2c>", line 1, in <module>
    twiss0 = madx.twiss(sequence='COD_HIMM.txt')

  File "D:\Program Files\lib\site-packages\cpymad\madx.py", line 407, in twiss
    return self.get_table('twiss', columns)

  File "D:\Program Files\lib\site-packages\cpymad\madx.py", line 560, in get_table
    proxy = TableProxy(table, self._libmadx)

  File "D:\Program Files\lib\site-packages\cpymad\madx.py", line 870, in __init__
    raise ValueError("Invalid table: {!r}".format(name))

ValueError: Invalid table: 'twiss'

COD_HIMM.txt

TITLE "HITFiL Project"
  OPTION, INFO, -ECHO, WARN;
  !ASSIGN, PRINT="HITFiL-cod-print"
  //ASSIGN, ECHO="HITFiL-cod-echo"
  //ASSIGN, INFO="HITFiL-cod-info"

BEAM, PARTICLE=carbon, CHARGE=6, energy=0.007;

!---------constant definition-----------
  mk1=1.5;
!-----Defining elements----
!----------drift------------------------------
  D11:drift,l=1.75;
  D12:drift,l=0.40;
  D13:drift,l=0.30;
  D14:drift,l=0.05;
  D15:drift,l=0.13;
  D16:drift,l=0.15;
  D17:drift,l=1.70;
  D18:drift,l=0.53;
  D19:drift,l=0.25;

  D21:drift,l=1.75;
  D22:drift,l=0.40;
  D23:drift,l=0.30;
  D24:drift,l=0.05;
  D25:drift,l=0.43;
  D26:drift,l=2.00;
  D27:drift,l=0.15;
  D28:drift,l=0.35;
  D29:drift,l=0.35;

  D31:drift,l=1.02;
  D32:drift,l=0.63;
  D33:drift,l=0.40;
  D34:drift,l=0.30;
  D35:drift,l=0.05;
  D36:drift,l=0.13;
  D37:drift,l=0.15;
  D38:drift,l=2.00;
  D39:drift,l=0.45;
  D3a:drift,l=0.33;

  D41:drift,l=0.81;
  D42:drift,l=0.44;
  D43:drift,l=0.15;
  D44:drift,l=0.40;
  D45:drift,l=0.30;
  D46:drift,l=0.05;
  D47:drift,l=0.43;
  D48:drift,l=2.00;
  D49:drift,l=0.35;
  D4a:drift,l=0.13;

!---------marker-----

    m1:marker;
    m2:marker;

!--------------constant difinition of dipoles------------------

 N=8;
 !bero=6.342738;
 !Bm=1.58568;
 ro=4.0; !bero/Bm
 leng=ro*(twopi/N);

Rr=0.07;! Reference radius of field measurement (Half good-field width)
a1=0.0;!4.5e-4
a2=0.0;!
a3=0.0;!

!---------definition of dipole without multipole-----------

 RB: SBEND, L=leng,ANGLE=TWOPI/N,K1=a1*(1/ro)*(1/Rr),HGAP=0.037,FINT=0.55,FINTX=0.55,E1=PI/8,E2=PI/8;

!--------dipole error--------------------------------------
   B11:RB;
   B12:RB;
   B21:RB;
   B22:RB;
   B31:RB;
   B32:RB;
   B41:RB;
   B42:RB;

   KB11: HKICKER;
   KB12: HKICKER;

   KB21: HKICKER;
   KB22: HKICKER;

   KB31: HKICKER;
   KB32: HKICKER;

   KB41: HKICKER;
   KB42: HKICKER;

   HB11: LINE=(B11,KB11);
   HB12: LINE=(B12,KB12);

   HB21: LINE=(B21,KB21);
   HB22: LINE=(B22,KB22);

   HB31: LINE=(B31,KB31);
   HB32: LINE=(B32,KB32);

   HB41: LINE=(B41,KB41);
   HB42: LINE=(B42,KB42);

!--------------quadrupole without multipole------------------

 QF: QUADRUPOLE, L=0.2, K1=0.799839688766;
 QD: QUADRUPOLE, L=0.2, K1=-1.00783349327;
 QFF: QUADRUPOLE, L=0.35, K1=1.038161630875;
 FQ: QUADRUPOLE, L=0.15,K1=0.00;

!-------------quadrupole error---------------------

  Q11:QF;
  Q12:QD;
  Q13:QFF;

  Q21:QF;
  Q22:QD;
  Q23:QFF;

  Q31:QF;
  Q32:QD;
  Q33:QFF;

  Q41:QF;
  Q42:QD;
  Q43:QFF;

  FQ11: FQ;
  FQ41: FQ;

!---------chromaticity sextupole--------------------
 SEXTCH:  sextupole,l=0.15, k2=0.0;
 SEXTCV:  sextupole,l=0.15, k2=0.0;

  SH11: SEXTCH;
  SH31: SEXTCH;
  SV21: SEXTCV;
  SV41: SEXTCV;

!-------------resonance sextupole--------------------

 SEXTR:  sextupole,l=0.15, k2=0.0;
  SR11: SEXTR;
  SR21: SEXTR;
  SR31: SEXTR;
  SR41: SEXTR;

!-------------CORRECTORS-------------------------
  CY: VKICKER, L=0.1;

  CY11:CY;
  CY21:CY;
  CY22:CY;
  CY31:CY;
  CY32:CY;
  CY33:CY;
  CY41:CY;
  CY42:CY;

!--------------MONITOR---------------------
  PKUP: MONITOR, L=0.25;

  BPM11: PKUP;
  BPM12: PKUP;

  BPM21: PKUP;

  BPM31: PKUP;
  BPM32: PKUP;

  BPM41: PKUP;
  BPM42: PKUP;

  PU11: LINE=(BPM11);
  PU12: LINE=(BPM12);

  PU21: LINE=(BPM21);

  PU31: LINE=(BPM31);
  PU32: LINE=(BPM32);

  PU41: LINE=(BPM41);
  PU42: LINE=(BPM42);

!--------ring definition-------------------------
  CELL1:Line=(D11,Q11,D12,HB11,D13,PU11,D14,CY11,D15,&
              SR11,D16,Q12,D16,FQ11,D17,SH11,D16,Q13,&
              D12,HB12,D19,PU12,D18);
  CELL2:Line=(D21,Q21,D22,HB21,D23,PU21,D24,CY21,D25,&
              Q22,D26,SR21,D27,Q23,D22,HB22,D28,SV21,&
              D25,CY22);
  CELL3:Line=(D31,CY31,D32,Q31,D33,HB31,D34,PU31,D35,CY32,&
              D36,SR31,D37,Q32,D38,SH31,D37,Q33,D33,&
              HB32,D39,CY33,D3a,PU32);
  CELL4:Line=(D41,PU41,D42,CY41,D43,Q41,D44,HB41,D45,&
              PU42,D46,CY42,D47,Q42,D48,SR41,D43,Q43,&
              D44,HB42,D49,SV41,D43,FQ41,D4a);

  HIMM: Line=(CELL1,-CELL2,CELL3,-CELL4);

USE, sequence=HIMM;

[coldfix]

twiss0 = madx.twiss(sequence='COD_HIMM.txt')

Like MAD-X, cpymad requires a sequence name (not file name) to pass to TWISS