How larger is the value of caliper by default when the method was set with “nearest” . about matchit HOT 4 CLOSED

Please see the documentation for the caliper argument at ?matchit.

from matchit.

Please see the documentation for the caliper argument at ?matchit.

Thank you very much!
We have read the document of Package ‘MatchIt’ (version 4.4.0) on page 18.
" caliper: for methods that allow it, the width(s) of the caliper(s) to use in matching. Should be a numeric vector with each value named according to the variable to which the caliper applies. To apply to the distance measure, the value should be unnamed. See the individual methods pages for information on whether and how this argument is used. The default is NULL for no caliper."

So we think that the default is NULL for no caliper in our situation as follow:

" 1:4 NN PS matching w/o replacement
m.outx4 <- matchit(treat ~ age + gender + BMI, data = ps2,
method = "nearest", distance = "glm",ratio=4)
"

That is, If we would not define a caliper, there is none caliper.
Did I ignore any important information?

Many thanks

from matchit.

That's correct. If unspecified, there is no caliper. See my justification in #110 if you're interested in why this is the default.

from matchit.

That's correct. If unspecified, there is no caliper. See my justification in #110 if you're interested in why this is the default.
Thanks, We were delighted to study your viewpoint.

from matchit.