anchor.diff:  c     The istatout array specifies output options for each individual
   c     state variable.  At present there are a maximum of 24 possible
   c     state variables, and this number may increase with the addition
  -c     of new material models.  For each state variable, the istatout
  -c     array can have either a zero (no output) or a one (output) in
  -c     each slot.  The options are as follows:
  -c
  -c       istatout(1,i):  Output cumulative total for current time step.
  -c       istatout(2,i):  Output increment over current time step.
  -c       istatout(3,i):  Output rate computed over current time step.
  +c     of new material models.  There are three types of state variable
  +c     output:
  +c
  +c           1  Total accumulated values for the current time step
  +c           2  Incremental values from the previous step to the current
  +c           3  Rates computed from the previous step to the current
   c
   c      Present state variables occur in groups of 6, corresponding to
   c      the number of stress/strain components, although this may change
  
positive.code: c      7-12:   Total strain
  c      13-18:  Viscous strain
  c      18-24:  Plastic strain
  c
  c     Error codes:
  c         0:  No error
  
negative.code: c~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  c
  c
        subroutine read_stateout(istatout,nstatout,kr,kw,kp,idout,idsk,
       & stfile,ofile,pfile,ierr,errstrng)
  c
  c...     reads integer array indicating which state variables
  c        to output.  It is assumed that the same set of variables are
  