Return df, fstatic, and r.squared in `estimateEffect`

Currently, there is no way for users to extract r.squared, df, fstatic, etc. out of estimateEffect() object. If stm is estimated like a regression model, I assume there should be need for getting these information.

Could these be added?

Reprex

# glm structure
glm <- lm(Sepal.Width ~ Sepal.Length + Petal.Width + Petal.Length, data = iris)
ls(summary(glm))
#>  [1] "adj.r.squared" "aliased"       "call"          "coefficients" 
#>  [5] "cov.unscaled"  "df"            "fstatistic"    "r.squared"    
#>  [9] "residuals"     "sigma"         "terms"

# stm structure
library(stm)
#> stm v1.3.6 successfully loaded. See ?stm for help. 
#>  Papers, resources, and other materials at structuraltopicmodel.com

stm <- estimateEffect(c(1) ~ treatment, gadarianFit, gadarian)
ls(summary(stm))
#> [1] "call"   "tables" "topics"

^{Created on 2021-05-14 by the reprex package (v2.0.0)}

Session info

``` r sessioninfo::session_info() #> - Session info --------------------------------------------------------------- #> setting value #> version R version 4.0.5 (2021-03-31) #> os Windows 10 x64 #> system x86_64, mingw32 #> ui RTerm #> language (EN) #> collate English_United States.1252 #> ctype English_United States.1252 #> tz America/New_York #> date 2021-05-14 #> #> - Packages ------------------------------------------------------------------- #> package * version date lib source #> backports 1.2.1 2020-12-09 [1] CRAN (R 4.0.3) #> cli 2.5.0 2021-04-26 [1] CRAN (R 4.0.5) #> crayon 1.4.1 2021-02-08 [1] CRAN (R 4.0.4) #> data.table 1.14.0 2021-02-21 [1] CRAN (R 4.0.4) #> digest 0.6.27 2020-10-24 [1] CRAN (R 4.0.4) #> ellipsis 0.3.2 2021-04-29 [1] CRAN (R 4.0.5) #> evaluate 0.14 2019-05-28 [1] CRAN (R 4.0.4) #> fansi 0.4.2 2021-01-15 [1] CRAN (R 4.0.4) #> fs 1.5.0 2020-07-31 [1] CRAN (R 4.0.4) #> glue 1.4.2 2020-08-27 [1] CRAN (R 4.0.4) #> highr 0.9 2021-04-16 [1] CRAN (R 4.0.5) #> htmltools 0.5.1.1 2021-01-22 [1] CRAN (R 4.0.5) #> knitr 1.33 2021-04-24 [1] CRAN (R 4.0.5) #> lattice 0.20-44 2021-05-02 [1] CRAN (R 4.0.5) #> lifecycle 1.0.0 2021-02-15 [1] CRAN (R 4.0.4) #> magrittr 2.0.1 2020-11-17 [1] CRAN (R 4.0.4) #> Matrix 1.2-18 2019-11-27 [1] CRAN (R 4.0.3) #> matrixStats 0.58.0 2021-01-29 [1] CRAN (R 4.0.4) #> pillar 1.6.0 2021-04-13 [1] CRAN (R 4.0.5) #> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.0.4) #> purrr 0.3.4 2020-04-17 [1] CRAN (R 4.0.4) #> Rcpp 1.0.6 2021-01-15 [1] CRAN (R 4.0.4) #> reprex 2.0.0 2021-04-02 [1] CRAN (R 4.0.5) #> rlang 0.4.11 2021-04-30 [1] CRAN (R 4.0.5) #> rmarkdown 2.8 2021-05-07 [1] CRAN (R 4.0.5) #> sessioninfo 1.1.1 2018-11-05 [1] CRAN (R 4.0.4) #> stm * 1.3.6 2021-05-10 [1] Github (bstewart/stm@7750a91) #> stringi 1.5.3 2020-09-09 [1] CRAN (R 4.0.3) #> stringr 1.4.0 2019-02-10 [1] CRAN (R 4.0.4) #> styler 1.4.1 2021-03-30 [1] CRAN (R 4.0.4) #> tibble 3.1.1 2021-04-18 [1] CRAN (R 4.0.5) #> utf8 1.2.1 2021-03-12 [1] CRAN (R 4.0.4) #> vctrs 0.3.8 2021-04-29 [1] CRAN (R 4.0.5) #> withr 2.4.2 2021-04-18 [1] CRAN (R 4.0.5) #> xfun 0.22 2021-03-11 [1] CRAN (R 4.0.4) #> yaml 2.2.1 2020-02-01 [1] CRAN (R 4.0.4) #> #> [1] C:/Program Files/R/R-4.0.5/library ```

bstewart / stm

Return df, fstatic, and r.squared in `estimateEffect` #255

Reprex