Hi Nick
What I am attempting to do (and there may be a much more simple solution) is to calculate the exact probability of observing a value of x or greater given that I expect to observe mu. The value of mu comes from a poisson regression and is potentially different for each observed value.
The code that I believe works is:
generate temp = 0
local i = 0
local cum = 0
generate prob = 0
while `i' <= cases {
local j = 1
local fact = 1
while `j' <= `i' {
local fact = `fact' * `j'
local j = `j' + 1
}
local cum = `cum' = ((exp(-poi_pred)*(poi_pred^`i'))/`fact')
local i = `i' + 1
replace prob = 1 - `cum' if `i' == cases & cases ~= 0
replace prob = 1 if cases == 0
}
There is also a program called cpoisson by Joseph Hilbe that can by easily modified to work for my scenario but it doesn't seem to return the answer the way I need it to.
Thanks
Patrick
>>> [email protected] 21/12/2005 8:46:33 am >>>
You can't write a program with exactly
this syntax. You could write an -egen-
function.
If you want a new variable as output,
why this question?
I could start speculating on what you might mean,
but better that you should tell us much more.
Indeed, please show us your program.
Nick
[email protected]
Patrick McElduff
> I want to write a program that has two arguements and
> returns a value so that I can use it in the form:
>
> generate temp = program(var1 var2)
>
> I have written the guts of the program to do the work but I
> don't know how to get the input and output in the form I want.
>
> Could you please tell me where I should start looking.
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