st: Connecting Data Points with Lines

[Jielu Lin <jielu.lin@case.edu>]

Dear all,

I'm modeling age-graded trajectories. Each individual case in my data
has 4 repeated observations. Then I tried to graph estimated
individual trajectories. Each individual should have a separate
trajectory which is not connected to another individual trajectory. In
the actual graph, within a person, the 4 estimated data points were
correctly connected. However, some trajectories were connected even
though these observations did not belong to the same person. This
happened to some cases, but not all of them. I've been for patterns of
these odd connections but so far it seems random.

I used the following codes:

xtmixed y age ||id: age, mle cov(un)
predict y_fitted, fitted
twoway line y_fitted age, connect(ascending)

Whether I use the codes or the pull-down menu gives me the same thing.

Thanks in advance.

Jielu Lin
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