anchor.diff:         elseif (abs(spts(j)-npts(l)).LE.eps) then
            dPhis(l,j) = 0.
          else
  +         dPhis(l,j) = 0.
  +         den = 1.          
            do i = 1,np+1
              if (i.NE.l) then
                den = den*(npts(l)-npts(i))
  
positive.code:    ErrStat = ErrID_None
     ErrMsg  = ""
  
     do l = 1,np+1
       do j = 1,ns
         dPhis(l,j) = 0.
         den = 1.
         if ((abs(spts(j)-1.).LE.eps).AND.(l.EQ.np+1)) then
           dPhis(l,j) = float((np+1)*np)/4.
         elseif ((abs(spts(j)+1.).LE.eps).AND.(l.EQ.1)) then
  
negative.code:      enddo
     enddo
  
     do j = igp,igp !1,ns
        do l = 1,np+1
           
         if(abs(spts(j)-npts(l)).LE.eps) then
           Ps(l,j) = 1.
         else
           dnum = 1.
           den = 1.
           do k = 1,np+1
             if (k.NE.l) then
               den = den*(npts(l) - npts(k))
  