st: define a matrix using its names of columns and rows

[Val�rie Orozco <Valerie.Orozco@toulouse.inra.fr>]

I have a matrix toto like

toto[3,2]
   b1  b2
a1   0   0
a2   0   0
a3   0   0

Does anyone know how I can use the names of columns and rows of the 
matrix to replace some elements.
Instead of doing mat toto[2,1] = -1, I would to write "mat toto["a2", 
"b1"] = -1" (but this last one is wrong since I have the error  "type 
mismatch") ???

What's surprising is that creating a matrix from another works : for 
example
. mat titi = J(5,4 , 1)
. mat list titi
titi[5,4]
   c1  c2  c3  c4
r1   1   1   1   1
r2   1   1   1   1
r3   1   1   1   1
r4   1   1   1   1
r5   1   1   1   1

. mat  titi[2,1] = toto["a2","b2"]
. mat list titi
titi[5,4]
   c1  c2  c3  c4
r1   1   1   1   1
r2   0   1   1   1
r3   1   1   1   1
r4   1   1   1   1
r5   1   1   1   1

Than k you.

val�rie

--

***********************
Val�rie Orozco
INRA ESR Toulouse - FRANCE
ESR INRA - BP52627 - 31326 Castanet Tolosan Cedex 
orozco@toulouse.inra.fr
05-61-28-50-97
***********************




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