RR S - Read Register variable - from list of variables

PURPOSE

To read value(s) from a list of values into a register variable(s). Useful to change input parameters while inside a 'DO' loop.

SEE ALSO

RR	[Read Register variables]
DO	[Start of DO loop (Scripting operation)]

USAGE

.OPERATION: RR S [var1],[var2]

.VALUE(S): 1,2,3,4.,5,6.0,7,8,9,10
[Enter the list of floating point value(s) to choose from. Maximum number of values is 24.]

.POSITION WITHIN LIST: 4
[The fourth and fifth values will be selected and placed in the register variables specified on the operation line. The number of values to be selected is determined by the number of register variables on the operation line.]

NOTES

1. 'RR S' may be used within a DO-loop to enter a set of numbers successively into a register variable:
   

       DO LB1 [iter]=1,5                             
          RR S [cuttoff]                        
          4.3,8.1,0.12,5.0,8.55 
          [iter]                
          .                                     
          .                                     
          .                                     
       LB1                                      
 

          For I=1, [cuttoff] will be filled with the value 4.3, and so
          forth.


          In releases of SPIDER prior to version: 16  this
          could be done using the convention that any set of
          parameter inputs inside a DO LOOP without an enclosing
          brace of '()' would automatically be treated as a 
          list selected by the loop index.  Sets of
          parameter input inside a DO LOOP with an enclosing
          brace of '()' would be treated as a 
          constant list of values.  This behavior is the most
          common source of problems in SPIDER procedures and has
          finally been dropped as of version 16. 

SUBROUTINES: READRQ, REG_SET, SHRINKQ, CHKSTR


CALLER:      DRIV1