How to add a macro/string variable to a matrix

[Frau Antje]

I run a structural break test using the command estat sbsingle for a large number of regressions. I would like to generate a matrix called mbreak with the estimation results. I have no problem adding the p-value and test statistic from the return list to my matrix, but I have difficulties, adding the break date. The break date is stored in the results list as a macro r(breaktest). How can I add it to my matrix? The break date variable is in date format...

It tried already:
matrix mbreak[`x',4] = r(breakdate)

or
local Date = r(breakdate)
matrix mbreak_`y'[`x',4] = `Date'

But it doesn't work.

Thanks in advance for your support!

[Alexis Penot]

matrix mbreak[`x',4] = `r(breakdate)' should work, shouldn't it?

[Frau Antje]

No, unfortunately I get the error message:
2011q2 not found

r(111);

2011q2 is the break date...

[Nick Cox]

Matrices in Stata can only contain numeric results. A quarterly date can be (for Stata, is) numeric, which may possibly help you.

. di yq(2011, 2)
205

[Frau Antje]

I found a solution:

1. first transforming the date variable to a numerical variable
2. running the test
3. adding this numerical variable to the matrix
4. transforming this matrix to a separate stata data file using svmat
5. transforming the numerical date variable to a official date variable...