This prevents running with twiss,centre and aperture in cases it give…

…s wrong results.

src/mad_aper.c

@@ -4,6 +4,7 @@
 
 #define MIN_DOUBLE 1.e-36
 
+int isSliced = 0;
 struct table;
 struct aper_node            /* aperture limit node */
 {
@@ -1240,6 +1241,11 @@ pro_aperture(struct in_cmd* cmd)
   struct aper_node *limit_pt = &limit_node;
 
   limit_pt = aperture(table, use_range, tw_cp, &tw_cnt, limit_pt);
+  /*If TWISS CENTRE is used and some elements with a non-zero length and aperture. Than the node interpolation is wrong. */
+  if(current_sequ->tw_centre==1 && isSliced==1){
+       warning("Aperture module - not possible to use TWISS, CENTRE=TRUE with thick apperture elements.", "Aperture command ignored");
+    return;
+  }
 
   if (limit_pt->n1 != -1) {
     printf("\n\nAPERTURE LIMIT: %s, n1: %g, at: %g\n\n", limit_pt->name, limit_pt->n1, limit_pt->s);
@@ -1391,6 +1397,7 @@ aperture(char *table, struct node* use_range[], struct table* tw_cp, int *tw_cnt
 
   /* get initial twiss parameters, from start of first element in range */
   aper_read_twiss(tw_cp->name, tw_cnt, &s_end, &x, &y, &px, &py, &betx, &bety, &dx, &dy);
+
   // LD: shift further results by one step (?) and finish outside the table
   //  (*tw_cnt)++;
   aper_adj_halo_si(ex, ey, betx, bety, bbeat, halox, haloy, halolength, haloxsi, haloysi);
@@ -1470,7 +1477,6 @@ aperture(char *table, struct node* use_range[], struct table* tw_cp, int *tw_cnt
       n1=999999; n1x_m=999999; n1y_m=999999; on_ap=-999999; nint=1;
 
       aper_read_twiss(tw_cp->name, tw_cnt, &s_end, &x, &y, &px, &py, &betx, &bety, &dx, &dy);
-
       aper_write_table(name, &n1, &n1x_m, &n1y_m, &r, &xshift, &yshift, &xoffset, &yoffset,
 		       apertype, &ap1, &ap2, &ap3, &ap4, &on_ap, &on_elem, &spec,
                        &s_end, &x, &y, &px, &py, &betx, &bety, &dx, &dy, table);
@@ -1503,6 +1509,7 @@ aperture(char *table, struct node* use_range[], struct table* tw_cp, int *tw_cnt
       node_n1   = 999999;
       true_node = 0;
       offs_node = 0;
+
 
       /* calculate the number of slices per node */
       if (true_flag == 0)
@@ -1518,7 +1525,13 @@ aperture(char *table, struct node* use_range[], struct table* tw_cp, int *tw_cnt
       if (!nint) nint = 1;
 
       /* do not interpolate 0-length elements*/
-      if (fabs(length) < MIN_DOUBLE ) is_zero_len = 1;
+      if (fabs(length) < MIN_DOUBLE ) {
+        is_zero_len = 1;
+      }
+      else{
+        isSliced = 1;
+      }
+
 
       /* slice the node, call survey if necessary, make twiss for slices*/
       interpolate_node(&nint);

src/mad_seq.h

@@ -50,6 +50,7 @@ struct sequence
   struct node_list* ex_nodes;   /* alphabetic list of nodes (no drifts) */
   struct table* tw_table;       /* pointer to latest twiss table created */
   int           tw_valid;       /* true if current tw_table is valid */
+  int           tw_centre;      /* true if twiss center option is triggered */        
   struct constraint_list* cl;   /* pointer to constraint list during match */
   struct vector_list* orbits;   /* pointer to list of stored orbits */
 };

src/mad_twiss.c

@@ -762,11 +762,19 @@ pro_twiss(void)
     }
   }
 
-  if(par_present("centre", current_twiss)) set_option("centre", &k);
+  if(par_present("centre", current_twiss)) {
+    set_option("centre", &k);
+    // Special check that it really is set to TRUE (not only included in the argument)
+    if(command_par_value("centre", current_twiss)>0){
+      current_sequ->tw_centre=1;
+    }
+  }
   else {
     k = 0;
+    current_sequ->tw_centre=0;
     set_option("centre", &k);
     k = 1;
+
   }
 
   name = command_par_string_user("keeporbit", current_twiss);
@@ -1024,6 +1032,7 @@ embedded_twiss(void)
     /* beta0 specified */
     embedded_twiss_beta[0] = buffer(cp->m_string->p[0]);
 
+
     /* START defining a TWISS input command for the sequence */
     tnl = local_twiss[0]->cmd_def->par_names;
     tpos = name_list_pos("beta0", tnl);