st: Looping graphs and changing graphs name

[Evelyne Fournier <efournier@chu-besancon.fr>]

Dear all,

I'm having a problem using levelsof.
I know this subject has been widely discussed in previous posts. 
Unfortunately my loop over values of a string variable doesn't want to 
work and I can't figure out why.

I have a dataset containing incidence et mortality rates by age 
categories (clage). I have a string variable containing cancer 
localisations (loc).
I want to graph incidence and mortality rates per age category and 
produce one graph per cancer localisation. I want the created graphs to 
have the name of the given cancer localisation.

My dataset looks the following
  ************
          loc     clage     incid     morta
   Système Nerveux  50-54   23.96       5.99
   Système Nerveux  55-59   30.11     10.03
   Système Nerveux  60-64   58.73      22.58
   Système Nerveux  65-69   49.92      16.64
   Système Nerveux  70-74   58.20       47.28
   Système Nerveux  75-79   121.10      60.55
   Système Nerveux  80-84   90.43     71.05
   Système Nerveux  85and +    103.26     150.20
**************

When I execute the following code, Stata doesn't go over the different 
localisations.
However, the loop works as long as I don't try to save the graph with 
the cancer localisation's name (command line   name("`lev'", replace) 
here under).
*******************************************
levelsof loc
foreach lev in `r(levels)' {
          preserve
           keep if loc=="`lev'"
   twoway (line incid clage, sort) ///
  (line morta clage, sort )  ///
 title("`lev'")  ///
name("`lev'", replace)
  restore
}
****************************************
I get the following message :
Système Nerveux : .twowaygraph_g.new (line incid clage, sort) (line 
morta clage, sort), title("Système Nerveux Central"): class type not
    found
r(4018);

Any help will be greatly appreciated.
Thanks,

Evelyne


Evelyne Fournier
Epidémiologiste
Registre des tumeurs du Doubs et du Territoire de Belfort
CHU Besancon,
2 Place Saint Jacques
25030 Besancon Cedex
France

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