Glance at a(n) nls object

Glance accepts a model object and returns a tibble::tibble() with exactly one row of model summaries. The summaries are typically goodness of fit measures, p-values for hypothesis tests on residuals, or model convergence information.

Glance never returns information from the original call to the modeling function. This includes the name of the modeling function or any arguments passed to the modeling function.

Glance does not calculate summary measures. Rather, it farms out these computations to appropriate methods and gathers the results together. Sometimes a goodness of fit measure will be undefined. In these cases the measure will be reported as NA.

Glance returns the same number of columns regardless of whether the model matrix is rank-deficient or not. If so, entries in columns that no longer have a well-defined value are filled in with an NA of the appropriate type.

Usage

# S3 method for class 'nls'
glance(x, ...)

Arguments

x

An nls object returned from stats::nls().

...

Additional arguments. Not used. Needed to match generic signature only. Cautionary note: Misspelled arguments will be absorbed in ..., where they will be ignored. If the misspelled argument has a default value, the default value will be used. For example, if you pass conf.lvel = 0.9, all computation will proceed using conf.level = 0.95. Two exceptions here are:

tidy() methods will warn when supplied an exponentiate argument if it will be ignored.
augment() methods will warn when supplied a newdata argument if it will be ignored.

Value

A tibble::tibble() with exactly one row and columns:

AIC: Akaike's Information Criterion for the model.
BIC: Bayesian Information Criterion for the model.
deviance: Deviance of the model.
df.residual: Residual degrees of freedom.
finTol: The achieved convergence tolerance.
isConv: Whether the fit successfully converged.
logLik: The log-likelihood of the model. [stats::logLik()] may be a useful reference.
nobs: Number of observations used.
sigma: Estimated standard error of the residuals.

Examples


# fit model
n <- nls(mpg ~ k * e^wt, data = mtcars, start = list(k = 1, e = 2))

# summarize model fit with tidiers + visualization
tidy(n)
#> # A tibble: 2 × 5
#>   term  estimate std.error statistic  p.value
#>   <chr>    <dbl>     <dbl>     <dbl>    <dbl>
#> 1 k       49.7      3.79        13.1 5.96e-14
#> 2 e        0.746    0.0199      37.5 8.86e-27
augment(n)
#> # A tibble: 32 × 4
#>      mpg    wt .fitted .resid
#>    <dbl> <dbl>   <dbl>  <dbl>
#>  1  21    2.62    23.0 -2.01 
#>  2  21    2.88    21.4 -0.352
#>  3  22.8  2.32    25.1 -2.33 
#>  4  21.4  3.22    19.3  2.08 
#>  5  18.7  3.44    18.1  0.611
#>  6  18.1  3.46    18.0  0.117
#>  7  14.3  3.57    17.4 -3.11 
#>  8  24.4  3.19    19.5  4.93 
#>  9  22.8  3.15    19.7  3.10 
#> 10  19.2  3.44    18.1  1.11 
#> # ℹ 22 more rows
glance(n)
#> # A tibble: 1 × 9
#>   sigma isConv     finTol logLik   AIC   BIC deviance df.residual  nobs
#>   <dbl> <lgl>       <dbl>  <dbl> <dbl> <dbl>    <dbl>       <int> <int>
#> 1  2.67 TRUE   0.00000204  -75.8  158.  162.     214.          30    32

library(ggplot2)

ggplot(augment(n), aes(wt, mpg)) +
  geom_point() +
  geom_line(aes(y = .fitted))


newdata <- head(mtcars)
newdata$wt <- newdata$wt + 1

augment(n, newdata = newdata)
#> # A tibble: 6 × 13
#>   .rownames      mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear
#>   <chr>        <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 Mazda RX4     21       6   160   110  3.9   3.62  16.5     0     1     4
#> 2 Mazda RX4 W…  21       6   160   110  3.9   3.88  17.0     0     1     4
#> 3 Datsun 710    22.8     4   108    93  3.85  3.32  18.6     1     1     4
#> 4 Hornet 4 Dr…  21.4     6   258   110  3.08  4.22  19.4     1     0     3
#> 5 Hornet Spor…  18.7     8   360   175  3.15  4.44  17.0     0     0     3
#> 6 Valiant       18.1     6   225   105  2.76  4.46  20.2     1     0     3
#> # ℹ 2 more variables: carb <dbl>, .fitted <dbl>

Usage

Arguments

See also

Value

Examples