R help - Dec 2002 - how to get Residual Standard Error

Hi,

I use lm or loess to make smoothing. After smoothing I need "Residual
Standard Error" in my script. Could you please tell me how can I get
this information?

Thanks,

"Zhongming Yang" <Zhongming.Yang at cchmc.org> writes:
> Hi,
> 
> I use lm or loess to make smoothing. After smoothing I need "Residual
> Standard Error" in my script. Could you please tell me how can I get
> this information?
A preferred way would be to use
 sqrt(deviance(fm)/df.residual(fm))
if fm is your fitted model. 

pFor example
> data(Formaldehyde)
> fm <- lm(optden ~ carb, data = Formaldehyde)
> summary(fm)
Call:
lm(formula = optden ~ carb, data = Formaldehyde)

Residuals:
        1         2         3         4         5         6 
-0.006714  0.001029  0.002771  0.007143  0.007514 -0.011743 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 0.005086   0.007834   0.649    0.552    
carb        0.876286   0.013535  64.744 3.41e-07 ***
---
Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` '
1

Residual standard error: 0.008649 on 4 degrees of freedom
Multiple R-Squared: 0.999,	Adjusted R-squared: 0.9988 
F-statistic:  4192 on 1 and 4 DF,  p-value: 3.409e-07 
> sqrt(deviance(fm)/df.residual(fm))
[1] 0.0086487

Thanks for your answer.

But I really want to know whether I can get "Residual Standard Error",
directly. If I use summary(), there is an item "Residual Standard
Error". So I think we might can access this information directly.

Thanks again,








> summary(mod)
Call:
loess(formula = y ~ x)

Number of Observations: 10 
Equivalent Number of Parameters: 4.95 
Residual Standard Error: 8.734e-16 
Trace of smoother matrix: 5.47 

Control settings:
  normalize:  TRUE 
  span      :  0.75 
  degree   :  2 
  family   :  gaussian
  surface  :  interpolate         cell = 0.2






>>> Douglas Bates <bates at stat.wisc.edu> 12/13/02 04:15PM
>>>
"Zhongming Yang" <Zhongming.Yang at cchmc.org> writes:
> Hi,
> 
> I use lm or loess to make smoothing. After smoothing I need
"Residual
> Standard Error" in my script. Could you please tell me how can I get
> this information?
A preferred way would be to use
 sqrt(deviance(fm)/df.residual(fm))
if fm is your fitted model. 

pFor example
> data(Formaldehyde)
> fm <- lm(optden ~ carb, data = Formaldehyde)
> summary(fm)
Call:
lm(formula = optden ~ carb, data = Formaldehyde)

Residuals:
        1         2         3         4         5         6 
-0.006714  0.001029  0.002771  0.007143  0.007514 -0.011743 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 0.005086   0.007834   0.649    0.552    
carb        0.876286   0.013535  64.744 3.41e-07 ***
---
Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` '
1

Residual standard error: 0.008649 on 4 degrees of freedom
Multiple R-Squared: 0.999,	Adjusted R-squared: 0.9988 
F-statistic:  4192 on 1 and 4 DF,  p-value: 3.409e-07 
> sqrt(deviance(fm)/df.residual(fm))
[1] 0.0086487

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