R help - May 2013 - slope coefficient of a quadratic regression bootstrap

Hello,

I want to know if two quadratic regressions are significantly different.
I was advised to make the test using
step 1 bootstrapping both quadratic regressions and get their slope
coefficients.
          (Let's call the slope coefficient *â*^1 and *â*^2)
step 2 use the slope difference *â*^1-*â*^2 and bootstrap the slope
coefficent
step 3   find out the sampling distribution above and calculate the % =0
step 4  multiple the % by 2

However, I am new to the package boot.
I wrote a code for step 1 and got a error message.

Please kindly advise how to modify it and thank you.

Elaine

code
require(boot)
function.fit2  <-  function(data){
          #data  <-  data[indices,]   #  select  obs.  in  bootstrap  sample
          fit2 <-lm(logDIS~logBMN+I(logBMN^2))
          coefficients(fit2)   #  return  coefficient  vector
          }

boot.fit2  <-  boot(dataN,  function.fit2,  1000)

error
> fit2.boot  <-  boot(dataN,  fun.fit2,  1000)
Error in statistic(data, original, ...) : unused argument (original)

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Hello all,

I found the following code worked.

code
require(boot)
function.fit2  <-  function(data,i){
          d  <-  data[i,]   #  select  obs.  in  bootstrap  sample
          fit2 <-lm(logDIS~logBMN+I(logBMN^2), data=dataN)
          coefficients(fit2)   #  return  coefficient  vector
          }

boot.fit2  <-  boot(dataN,  function.fit2,  1000)



On Mon, May 6, 2013 at 7:36 AM, Elaine Kuo <elaine.kuo.tw@gmail.com>
wrote:
> Hello,
>
> I want to know if two quadratic regressions are significantly different.
> I was advised to make the test using
> step 1 bootstrapping both quadratic regressions and get their slope
> coefficients.
>           (Let's call the slope coefficient *â*^1 and *â*^2)
> step 2 use the slope difference *â*^1-*â*^2 and bootstrap the slope
> coefficent
> step 3   find out the sampling distribution above and calculate the % =0
> step 4  multiple the % by 2
>
> However, I am new to the package boot.
> I wrote a code for step 1 and got a error message.
>
> Please kindly advise how to modify it and thank you.
>
> Elaine
>
> code
> require(boot)
> function.fit2  <-  function(data){
>           #data  <-  data[indices,]   #  select  obs.  in  bootstrap
>  sample
>           fit2 <-lm(logDIS~logBMN+I(logBMN^2))
>           coefficients(fit2)   #  return  coefficient  vector
>           }
>
> boot.fit2  <-  boot(dataN,  function.fit2,  1000)
>
> error
> > fit2.boot  <-  boot(dataN,  fun.fit2,  1000)
> Error in statistic(data, original, ...) : unused argument (original)
>
>
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