summarize should check if geometry is used

[kylebutts]

I know this is a proof-of-concept, so feel free to ignore. Say you have data with the same geometry across the group. In sf, I would do |> summarize(geometry = geometry[1]) to avoid the costly operation. This doesn't work in sdf currently (see below). Also, the new .by syntax causes problems FYI

# %%
library(tidyverse)
#> Warning: package 'ggplot2' was built under R version 4.3.1
#> Warning: package 'stringr' was built under R version 4.3.1
library(sf) 
#> Linking to GEOS 3.11.0, GDAL 3.5.3, PROJ 9.1.0; sf_use_s2() is TRUE
library(sdf)
library(tictoc)

data(guerry, package = "sfdep")
g <- dplyr::select(guerry, code_dept, crime_pers, region)

# %% `sf`
tic()
g |>
  summarize(
    mean_crime_pers = mean(crime_pers, na.rm = TRUE),
    .by = region
  )
#> Simple feature collection with 5 features and 2 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 47680 ymin: 1703258 xmax: 1031401 ymax: 2677441
#> CRS:           NA
#> # A tibble: 5 × 3
#>   region mean_crime_pers                                                geometry
#>   <fct>            <dbl>                                          <MULTIPOLYGON>
#> 1 E               20119. (((381847 1762775, 381116 1763059, 379972 1762874, 378…
#> 2 N               22592. (((381847 1762775, 381116 1763059, 379972 1762874, 378…
#> 3 C               22654. (((381847 1762775, 381116 1763059, 379972 1762874, 378…
#> 4 S               11954. (((381847 1762775, 381116 1763059, 379972 1762874, 378…
#> 5 W               22485. (((381847 1762775, 381116 1763059, 379972 1762874, 378…
toc()
#> 0.23 sec elapsed

tic()
g |>
  summarize(
    mean_crime_pers = mean(crime_pers, na.rm = TRUE),
    g = geometry[1],
    .by = region
  )
#> Simple feature collection with 5 features and 2 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 382200 ymin: 1920016 xmax: 894622 ymax: 2564568
#> CRS:           NA
#> # A tibble: 5 × 3
#>   region mean_crime_pers                                                       g
#>   <fct>            <dbl>                                          <MULTIPOLYGON>
#> 1 E               20119. (((801150 2092615, 800669 2093190, 800688 2095430, 800…
#> 2 N               22592. (((729326 2521619, 729320 2521230, 729280 2518544, 728…
#> 3 C               22654. (((710830 2137350, 711746 2136617, 712430 2135212, 712…
#> 4 S               11954. (((747008 1925789, 746630 1925762, 745723 1925138, 744…
#> 5 W               22485. (((456425 2120055, 456229 2120382, 455943 2121064, 456…
toc()
#> 0.015 sec elapsed

# %% `sdf`
g_sdf <- as_sdf(g)

tic()
g_sdf |>
  group_by(region) |>
  summarize(
    mean_crime_pers = mean(crime_pers, na.rm = TRUE)
  )
#> Spatial Data Frame
#> Geometry Type: sfc_MULTIPOLYGON
#> Bounding box: xmin: 47680 ymin: 1703258 xmax: 1031401 ymax: 2677441
#> # A tibble: 5 × 3
#>   region mean_crime_pers                                                geometry
#>   <fct>            <dbl>                                          <MULTIPOLYGON>
#> 1 C               22654. (((710830 2137350, 711746 2136617, 712430 2135212, 712…
#> 2 E               20119. (((801150 2092615, 800669 2093190, 800688 2095430, 800…
#> 3 N               22592. (((729326 2521619, 729320 2521230, 729280 2518544, 728…
#> 4 S               11954. (((747008 1925789, 746630 1925762, 745723 1925138, 744…
#> 5 W               22485. (((456425 2120055, 456229 2120382, 455943 2121064, 456…
toc()
#> 0.139 sec elapsed

tic()
g_sdf |>
  group_by(region) |>
  summarize(
    mean_crime_pers = mean(crime_pers, na.rm = TRUE),
    g = geometry[1]
  )
#> Error:
#> ! The `j` argument of `[[.tbl_df()` can't be a vector of length 2 as of
#>   tibble 3.0.0.
#> ℹ Recursive subsetting is deprecated for tibbles.
#> Backtrace:
#>      ▆
#>   1. ├─dplyr::summarize(...)
#>   2. └─sdf::summarise.sdf(...)
#>   3.   └─sdf::as_sdf(res)
#>   4.     ├─tibble::new_tibble(...)
#>   5.     │ └─rlang::pairlist2(...)
#>   6.     ├─sdf:::validate_bbox(bounding_box(x[[geom_col]]))
#>   7.     │ └─base::stopifnot(...)
#>   8.     ├─sdf::bounding_box(x[[geom_col]])
#>   9.     ├─x[[geom_col]]
#>  10.     └─tibble:::`[[.tbl_df`(x, geom_col)
#>  11.       └─tibble:::tbl_subset2(x, j = i, j_arg = substitute(i))
#>  12.         └─lifecycle::deprecate_stop(...)
#>  13.           └─lifecycle:::deprecate_stop0(msg)
#>  14.             └─rlang::cnd_signal(...)
toc()
#> 0.026 sec elapsed

^{Created on 2023-12-06 with reprex v2.0.2}