Saving margins results in a program to use it in simulate

[Jay Rege]

Dear all,

I have written the following program

program define myprog1

replace pseudoclass = irecode(runiform(),prob_1, prob_1 + prob_2, prob_1 + prob_2 + prob_3)
reg dep_var i.trial##i.pseudoclass
margins i.trial, at(pseudoclass=(1(1)3)) 
end

Now I want to conduct a simulation using the results of margins.

However, I can not see in the margins help file how to refer to the prdicted values.

If I run e.g.

simulate _se _b, reps(100): myprog1

It worlks perfectly.

However, If I run something like

simulate _margins, reps(100): myprog1

I get the error message

at values for factor pseudoclass do not sum to 1
an error occurred when simulate executed myprog1

Which does not make any sense to me as at values are not supposed to sum up to 1

Can anyone help me with retriving the predicted values.

Many Thanks

[Jay Rege]

Sorry, there was an error in my code. The correct program code is

program define myprog1 
 replace pseudoclass = irecode(runiform(),prob_1, prob_1 + prob_2, prob_1 + prob_2 + prob_3) reg dep_var i.trial##i.pseudoclass margins trial, at(pseudoclass=(0(1)2))  end

However, for

simulate _margins, reps(100): myprog1

I now get the error message

_margins not found
error in expression: _margins

While, at least to my understanding, _margins sould be available in (r)

[Jay Rege]

Adding "post" in the margins command and refering to _b solved the problem.

 
 program define myprog1  replace pseudoclass = irecode(runiform(),prob_1, prob_1 + prob_2, prob_1 + prob_2 + prob_3)  reg dep_var i.trial##i.pseudoclass  margins trial, at(pseudoclass=(0(1)2)) post  end simulate _b, reps(100): myprog1

Sorry for the confusion