using exists with coef from an arima fit
Erin Hodgess wrote:
Dear R People: I have the output from an arima model fit in an object xxx. I want to verify that the ma1 coefficient is there, so I did the following:
xxx$coef
ar1 ar2 ma1 intercept 1.3841297 -0.4985667 -0.9999996 -0.1091657
str(xxx$coef)
Named num [1:4] 1.384 -0.499 -1 -0.109 - attr(*, "names")= chr [1:4] "ar1" "ar2" "ma1" "intercept"
exists('xxx$coef["ma1"]')
[1] FALSE Other than using xxx$coef[3], is there another way to check this, please? Thanks in advance, Sincerely, Erin
co <- coef(xxx)["ma1"]
#or co <- coef(xxx)[["ma1"]] depending on whether you want to
# preserve the name
exists("co")
#[1] TRUE
-Peter Ehlers