Glance at a(n) rq 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 'rq'
glance(x, ...)

Arguments

x

An rq object returned from quantreg::rq().

...

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.

Details

Only models with a single tau value may be passed. For multiple values, please use a purrr::map() workflow instead, e.g.

taus %>%
  map(function(tau_val) rq(y ~ x, tau = tau_val)) %>%
  map_dfr(glance)

See also

glance(), quantreg::rq()

Other quantreg tidiers: augment.nlrq(), augment.rq(), augment.rqs(), glance.nlrq(), tidy.nlrq(), tidy.rq(), tidy.rqs()

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.

df.residual

Residual degrees of freedom.

logLik

The log-likelihood of the model. [stats::logLik()] may be a useful reference.

tau

Quantile.

Examples

# load modeling library and data
library(quantreg)

data(stackloss)

# median (l1) regression fit for the stackloss data.
mod1 <- rq(stack.loss ~ stack.x, .5)

# weighted sample median
mod2 <- rq(rnorm(50) ~ 1, weights = runif(50))

# summarize model fit with tidiers
tidy(mod1)
#> # A tibble: 4 × 5
#>   term              estimate conf.low conf.high   tau
#>   <chr>                <dbl>    <dbl>     <dbl> <dbl>
#> 1 (Intercept)       -39.7     -53.8    -24.5      0.5
#> 2 stack.xAir.Flow     0.832     0.509    1.17     0.5
#> 3 stack.xWater.Temp   0.574     0.272    3.04     0.5
#> 4 stack.xAcid.Conc.  -0.0609   -0.278    0.0153   0.5
glance(mod1)
#> # A tibble: 1 × 5
#>     tau logLik      AIC   BIC df.residual
#>   <dbl> <logLik>  <dbl> <dbl>       <int>
#> 1   0.5 -50.15272  108.  112.          17
augment(mod1)
#> # A tibble: 21 × 5
#>    stack.loss stack.x[,"Air.Flow"] [,"Water.Temp"]    .resid .fitted  .tau
#>         <dbl>                <dbl>           <dbl>     <dbl>   <dbl> <dbl>
#>  1         42                   80              27  5.06e+ 0    36.9   0.5
#>  2         37                   80              27 -1.42e-14    37     0.5
#>  3         37                   75              25  5.43e+ 0    31.6   0.5
#>  4         28                   62              24  7.63e+ 0    20.4   0.5
#>  5         18                   62              22 -1.22e+ 0    19.2   0.5
#>  6         18                   62              23 -1.79e+ 0    19.8   0.5
#>  7         19                   62              24 -1.00e+ 0    20     0.5
#>  8         20                   62              24 -7.11e-15    20     0.5
#>  9         15                   58              23 -1.46e+ 0    16.5   0.5
#> 10         14                   58              18 -2.03e- 2    14.0   0.5
#> # ℹ 11 more rows
#> # ℹ 1 more variable: stack.x[3] <dbl>

tidy(mod2)
#> # A tibble: 1 × 5
#>   term        estimate conf.low conf.high   tau
#>   <chr>          <dbl> <lgl>    <lgl>     <dbl>
#> 1 (Intercept)    0.124 NA       NA          0.5
glance(mod2)
#> # A tibble: 1 × 5
#>     tau logLik      AIC   BIC df.residual
#>   <dbl> <logLik>  <dbl> <dbl>       <int>
#> 1   0.5 -78.76986  160.  161.          49
augment(mod2)
#> # A tibble: 50 × 5
#>    `rnorm(50)` `(weights)` .resid .fitted  .tau
#>          <dbl>       <dbl>  <dbl>   <dbl> <dbl>
#>  1     0.393       0.696    0.269   0.124   0.5
#>  2     0.458       0.266    0.334   0.124   0.5
#>  3    -1.22        0.660   -1.34    0.124   0.5
#>  4    -1.12        0.212   -1.25    0.124   0.5
#>  5     0.993       0.00527  0.869   0.124   0.5
#>  6    -1.83        0.103   -1.96    0.124   0.5
#>  7     0.124       0.287    0       0.124   0.5
#>  8     0.591       0.444    0.467   0.124   0.5
#>  9     0.805       0.693    0.681   0.124   0.5
#> 10     0.00754     0.0209  -0.116   0.124   0.5
#> # ℹ 40 more rows

# varying tau to generate an rqs object
mod3 <- rq(stack.loss ~ stack.x, tau = c(.25, .5))

tidy(mod3)
#> # A tibble: 8 × 5
#>   term               estimate conf.low conf.high   tau
#>   <chr>                 <dbl>    <dbl>     <dbl> <dbl>
#> 1 (Intercept)       -3.6 e+ 1  -59.0     -7.84    0.25
#> 2 stack.xAir.Flow    5.00e- 1    0.229    0.970   0.25
#> 3 stack.xWater.Temp  1.00e+ 0    0.286    2.26    0.25
#> 4 stack.xAcid.Conc. -4.58e-16   -0.643    0.0861  0.25
#> 5 (Intercept)       -3.97e+ 1  -53.8    -24.5     0.5 
#> 6 stack.xAir.Flow    8.32e- 1    0.509    1.17    0.5 
#> 7 stack.xWater.Temp  5.74e- 1    0.272    3.04    0.5 
#> 8 stack.xAcid.Conc. -6.09e- 2   -0.278    0.0153  0.5 
augment(mod3)
#> # A tibble: 42 × 5
#>    stack.loss stack.x[,"Air.Flow"] [,"Water.Temp"] .tau     .resid .fitted
#>         <dbl>                <dbl>           <dbl> <chr>     <dbl>   <dbl>
#>  1         42                   80              27 0.25   1.10e+ 1    31.0
#>  2         42                   80              27 0.5    5.06e+ 0    36.9
#>  3         37                   80              27 0.25   6.00e+ 0    31.0
#>  4         37                   80              27 0.5   -1.42e-14    37  
#>  5         37                   75              25 0.25   1.05e+ 1    26.5
#>  6         37                   75              25 0.5    5.43e+ 0    31.6
#>  7         28                   62              24 0.25   9.00e+ 0    19  
#>  8         28                   62              24 0.5    7.63e+ 0    20.4
#>  9         18                   62              22 0.25   1.00e+ 0    17.0
#> 10         18                   62              22 0.5   -1.22e+ 0    19.2
#> # ℹ 32 more rows
#> # ℹ 1 more variable: stack.x[3] <dbl>

# glance cannot handle rqs objects like `mod3`--use a purrr
# `map`-based workflow instead