[R] Loop with string variable AND customizable "summary" output

[C.Rosa at lse.ac.uk]

Dear All,

I am using R for my research and I have two questions about it:

1) is it possible to create a loop using a string, instead of a numeric vector? I have in mind a specific problem:

Suppose you have 2 countries: UK, and USA, one dependent (y) and one independent variable (y) for each country (vale a dire: yUK, xUK, yUSA, xUSA) and you want to run automatically the following regressions:

 

for (i in c("UK","USA"))

output{i}<-summary(lm(y{i} ~ x{i}))

 

In other words, at the end I would like to have two objects as output: "outputUK" and "outputUSA", which contain respectively the results of the first and second regression (yUK on xUK and yUSA on xUSA). 

 

2) in STATA there is a very nice code ("outreg") to display nicely (and as the user wants to) your regression results.

Is there anything similar in R / R contributed packages? More precisely, I am thinking of something that is close in spirit to "summary" but it is also customizable. For example, suppose you want different Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 or a different format display (i.e. without "t value" column) implemented automatically (without manually editing it every time).

In alternative, if I was able to see it, I could modify the source code of the function "summary", but I am not able to see its (line by line) code. Any idea?

Or may be a customizable regression output already exists?

Thanks really a lot!

Carlo