Data and Variables in Tao

Data

In order to optimize, you must tell Tao what quantities that you want to calculate that will contribute to the merit function. The basic structure has several: d2_data, which contains d1_data, which contains individual datums. You input these in the tao.init file as:

&tao_d2_data
    d2_data%name = 'twiss'
    n_d1_data = 2
/
&tao_d1_data
    ix_d1_data = 1
    d1_data%name = 'end'
    datum( 1) =  'beta.a'     '' '' 'END'   'target'  12.5   1e1  
    datum( 2) =  'alpha.a'    '' '' 'END'   'target'  -1     1e2
/ 
&tao_d1_data
    ix_d1_data = 2
    d1_data%name = 'max'
    datum( 1) =  'beta.a'    '' 'Q1' 'END'   'max'  100   1e1
    datum( 2) =  'eta.x'     '' 'Q1' 'END'   'abs_max'  1     1e2
/ 

The first datum means that beta.a at element END should be 12.5 m with a weight of 10. If the model beta function is, say, 20 m at element END, then this datum would contribute 10*(20 - 12.5)^2 to the merit function.

---

Variables

Variables must be defined in order to optimize. The simplest possible variable definition is:

&tao_var
  v1_var%name = 'quad'
  default_step = 1e-4
  default_attribute = 'k1'
  search_for_lat_eles = 'Quad::*'
  ! or: 
  ! var(1:)%ele_name = 'Q1', 'Q2', 'Q3', 'Q4', 'Q5', 'Q6'
/

In tao you will then see (if the elements exist) the variables in a short notation:

Tao> sho var
       Name                                      Using for Optimization
    quad[1:6]

or a more detailed list:

Tao> sho var quad
Variable name:  quad

 Index  Controlled Attributes(s)    Meas         Model        Design  Useit_opt
     1  Q1[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
     2  Q2[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
     3  Q3[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
     4  Q4[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
     5  Q5[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
     6  Q6[K1]                  8.6924-311    0.0000E+00    0.0000E+00       F
 Index  Controlled Attributes(s)    Meas         Model        Design  Useit_opt

A tao_var is thus an array of variables, each of which can have individually set attributes. Type:

Tao> sho var quad[2]
%ele_name         = Q2
%attrib_name      = K1
...

to see a complete list