Documentation and also update some tests

Author: tpersson

doc/latexuguide/elements.tex

@@ -1810,4 +1810,26 @@ \section{Change of reference system}
 be referred to the new coordinate system where both translations and
 rotations are applied.
 
-%%% END
+
+\section{SixTrack Marker}
+
+\madbox{
+label: SIXMARKER, \= ELTYPE=real, ATTR=\{real, \ldots \},  \\
+               \> F3STRING=string, F3VECTOR=\{real, \ldots \} ;
+}
+f3string="NEW ELEMENT {newline} {0}, {1} {newline}NEXT"
+The \texttt{SIXMARKER} element allows the definition of an arbitrary marker that is converted to SixTrack.
+The element has no impact in MAD-X.
+\begin{madlist}
+   \ttitem{ELTYPE} is the element type number in SixTrack, converted to the first column in fc.2.
+   \ttitem{ATTR} This defines the remaining columns of the fc.2 file.
+   \ttitem{F3STRING} Defines the String that is written to the fc.3 file, \{newline\} creates a new line in the output
+   and \{0\}\ldots\{10\} are being replaced with the values in F3VECTOR.
+   \ttitem{F3VECTOR} The values defined will be converted to the location defined in the F3STRING. 
+\end{madlist}
+
+\textbf{Example:}
+\madxmp{
+DR1: \= DRIFT, \= L=1.5; \\
+DR2: \> DRIFT, \> L=DR1->L;
+}

src/mad_6track.c

@@ -3251,10 +3251,10 @@ write_f3_sixmarker(struct element* el){
   if (!f3) f3 = fopen("fc.3", "w");
 
   tmp =command_par_string("f3string",el->def);
-  nl = element_vector(el, "attr", attrtemp);
+  nl = element_vector(el, "f3vector", attrtemp);
 
   for(int i=0; i<nl; i++){
-    
+
     sprintf(str_att_value, "%12.8e", attrtemp[i]);
 
     strcpy(nstr2,"{");

tests/test-c6t-7/fc.3.ref

@@ -1,3 +1,3 @@
-NEW ELEMENT 
- 1.00000000e-01, 2.00000000e+00 
+NEW_ELEMENT 
+ 2.00000000e-01, 5.00000000e-01 
 NEXT

tests/test-c6t-7/test-c6t-7.madx

@@ -1,6 +1,6 @@
 circum=10;
 
-sm1:sixmarker, eltype=2, attr={0.1,2,3,4,5,6,7}, f3string="NEW ELEMENT {newline} {0}, {1} {newline}NEXT", f3vector={0.2, 0.5};
+sm1:SIXMARKER, eltype=2, attr={0.1,2,3,4,5,6,7}, f3string="NEW_ELEMENT {newline} {0}, {1} {newline}NEXT", f3vector={0.2, 0.5};
 m1: multipole, knl={0, 0.2};
 show, sm1;