Create and export spatial matrix: spmatrix does not find the matrix created in Mata

[Petre Car]

I have a code that partially works to create a spatial matrix:

egen id = group(IOCode), label lname(IOCode)

spset id

local var v1 v2 v3 v4 v5

mata: st_matrix("c",st_data((1,5),"`var'"))

matrix coln c= `var'

mat list c

spmatrix spfrommata Wmat=c id

Although mat list c shows the matrix, spmatrix leads to the error:

matrix c not found

[Petre Car]

I've also tried:

. local var v1 v2 v3 v4 v5

. mata:
------------------------------------------------- mata (type end to exit) ----------------------------------------------------------------------------------------------------------------
:
: id = st_data(., "_ID")

:
: c = st_matrix("c",st_data((1,5),"`var'"))

:
: end
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

.
. spmatrix spfrommata myIdist = c id

with the error: number of rows in matname must be > 0

[Sebastian Kripfganz]

Your Mata code generates a Stata matrix c, not a Mata matrix c. To generate the latter, simply type

local var v1 v2 v3 v4 v5
mata:
id = st_data(., "_ID")
c = st_data((1,5),"`var'")
end
spmatrix spfrommata myIdist = c id

Aside from that: Do you really just have 5 units in your id vector?