Hi Dear,

When I run xtcsd, pesaran after estimating fixed effects model in Stata.....I get the error saying "unknown function *sqrt()
r(133);"
and when I run xtcsd, frees or xtcsd, friedman....In both cases, I get the error saying "no observations
r(2000);"

Can you please guide me what can be the possible reasons for these errors?

Thank you.