Storing results in a matrix

[Stephen Okiya]

Hi Stata users,

I would like to store the results of cross-tabulations in a matrix. I have one variable that am cross-tabbing with other variables and would want the results for the first tabulation to be stored in the first and second columns of the matrix, results for the second tabulation to be stored in the third and fourth columns of the matrix

The data example is

* Example generated by -dataex-. For more info, type help dataex
clear
input str3 var1 str4(var2 var3)
"yes" "low"  "high"
"no"  "high" "low" 
"yes" "low"  "high"
"yes" "high" "low" 
"yes" "high" "low" 
"yes" "high" "high"
"no"  "high" "high"
"yes" "low"  "low" 
"no"  "low"  "high"
"no"  "high" "low" 
"yes" "high" "high"
"no"  "low"  "low" 
"yes" "low"  "high"
"no"  "high" "low" 
"yes" "low"  "high"
"no"  "high" "high"
"yes" "low"  "high"
"yes" "high" "low" 
"yes" "low"  "low" 
"yes" "low"  "low" 
"yes" "high" "low" 
"yes" "low"  "low" 
end

The code am using is

    matrix P = J(2,4,.)
    
    local i = 1
    
    foreach v of varlist var2 var3 {
        ta var1 `v', matcell(x)
        mata: st_matrix("xx", (st_matrix("x") * 100) :/ rowsum(st_matrix("x")))
        matrix list xx
        matrix P[1,`i'] = xx
        local i = `i' + 1
    }
    
    matrix list P

Thanks in advance!

[Stephen Okiya]

I have found a tiny error in my code

local i = `i' + 1

should be

local i = `i' + 2