Imagine I want to calculate the percentage of the vote that Kamela Harris got in Albany County using this data frame. I want to add up all the Kamela Harris columns and divide by the total votes in the Presidential race. There is a quick trick to do this with R using the tidyverse and purr library.

  mutate(
    harris_percent =
      reduce(select(., contains('kamala_d_harris')), `+`)/
      reduce(select(., contains('electors_for_president_and_vice_president')), `+`)
    )

The above code uses the reduce command against a subset of the dataframe containing the Kamala Harris columns which reduces them to one column in a vectorized format using the addition operator. You can use any vectorized operation or function rather then `+` there.

Here are column names for reference:

[1] "town"                                                             "ward"                                                            
  [3] "ed"                                                               "ballots_cast_total_ballots_cast"                                 
  [5] "ballots_cast_blank_ballots_cast2"                                 "electors_for_president_and_vice_president_dem_kamala_d_harris"   
  [7] "electors_for_president_and_vice_president_rep_donald_j_trump"     "electors_for_president_and_vice_president_con_donald_j_trump"    
  [9] "electors_for_president_and_vice_president_wfp_kamala_d_harris"    "electors_for_president_and_vice_president_write_in"              
 [11] "electors_for_president_and_vice_president_over_votes"             "electors_for_president_and_vice_president_under_votes"           
 [13] "united_states_senator_dem_kirsten_e_gillibrand"                   "united_states_senator_rep_michael_d_sapraicone"                  
 [15] "united_states_senator_con_michael_d_sapraicone"                   "united_states_senator_wfp_kirsten_e_gillibrand"                  
 [17] "united_states_senator_lar_diane_sare"                             "united_states_senator_write_in3"                                 
 [19] "united_states_senator_over_votes4"                                "united_states_senator_under_votes5"                              
 [21] "representative_in_congress_20th_district_dem_paul_d_tonko"        "representative_in_congress_20th_district_rep_kevin_m_waltz"      
 [23] "representative_in_congress_20th_district_con_kevin_m_waltz"       "representative_in_congress_20th_district_wfp_paul_d_tonko"       
 [25] "representative_in_congress_20th_district_write_in6"               "representative_in_congress_20th_district_over_votes7"            
 [27] "representative_in_congress_20th_district_under_votes8"            "state_senator_43rd_district_dem_alvin_gamble"                    
 [29] "state_senator_43rd_district_rep_jake_ashby"                       "state_senator_43rd_district_con_jake_ashby"                      
 [31] "state_senator_43rd_district_write_in9"                            "state_senator_43rd_district_over_votes10"                        
 [33] "state_senator_43rd_district_under_votes11"                        "state_senator_46th_district_dem_patricia_a_fahy"                 
 [35] "state_senator_46th_district_rep_ted_danz_jr"                      "state_senator_46th_district_con_ted_danz_jr"                     
 [37] "state_senator_46th_district_wfp_patricia_a_fahy"                  "state_senator_46th_district_write_in12"                          
 [39] "state_senator_46th_district_over_votes13"                         "state_senator_46th_district_under_votes14"                       
 [41] "member_of_assembly_102nd_district_dem_janet_s_tweed"              "member_of_assembly_102nd_district_rep_christopher_tague"         
 [43] "member_of_assembly_102nd_district_con_christopher_tague"          "member_of_assembly_102nd_district_wfp_janet_s_tweed"             
 [45] "member_of_assembly_102nd_district_write_in15"                     "member_of_assembly_102nd_district_over_votes16"                  
 [47] "member_of_assembly_102nd_district_under_votes17"                  "member_of_assembly_107th_district_dem_chloe_e_pierce"            
 [49] "member_of_assembly_107th_district_rep_scott_h_bendett"            "member_of_assembly_107th_district_con_scott_h_bendett"           
 [51] "member_of_assembly_107th_district_write_in18"                     "member_of_assembly_107th_district_over_votes19"                  
 [53] "member_of_assembly_107th_district_under_votes20"                  "member_of_assembly_108th_district_john_t_mc_donald_iii"          
 [55] "member_of_assembly_108th_district_write_in21"                     "member_of_assembly_108th_district_over_votes22"                  
 [57] "member_of_assembly_108th_district_under_votes23"                  "member_of_assembly_109th_district_dem_gabriella_a_romero"        
 [59] "member_of_assembly_109th_district_rep_alicia_m_purdy"             "member_of_assembly_109th_district_con_alicia_m_purdy"            
 [61] "member_of_assembly_109th_district_wfp_gabriella_a_romero"         "member_of_assembly_109th_district_write_in24"                    
 [63] "member_of_assembly_109th_district_over_votes25"                   "member_of_assembly_109th_district_under_votes26"                 
 [65] "member_of_assembly_110th_district_dem_phillip_g_steck"            "member_of_assembly_110th_district_rep_jeff_madden"               
 [67] "member_of_assembly_110th_district_con_jeff_madden"                "member_of_assembly_110th_district_wfp_phillip_g_steck"           
 [69] "member_of_assembly_110th_district_write_in27"                     "member_of_assembly_110th_district_over_votes28"                  
 [71] "member_of_assembly_110th_district_under_votes29"                  "district_attorney_dem_lee_c_kindlon"                             
 [73] "district_attorney_rep_ralph_f_ambrosio"                           "district_attorney_wfp_lee_c_kindlon"                             
 [75] "district_attorney_write_in30"                                     "district_attorney_over_votes31"                                  
 [77] "district_attorney_under_votes32"                                  "surrogate_court_judge_dem_deborah_s_kearns"                      
 [79] "surrogate_court_judge_wfp_deborah_s_kearns"                       "surrogate_court_judge_write_in33"                                
 [81] "surrogate_court_judge_over_votes34"                               "surrogate_court_judge_under_votes35"                             
 [83] "family_court_judge_dem_jaime_lynn_czajka"                         "family_court_judge_dem_jillian_e_faison"                         
 [85] "family_court_judge_dem_ricja_d_rice_ghyll"                        "family_court_judge_wfp_jasper_mills_iii"                         
 [87] "family_court_judge_wfp_jillian_e_faison"                          "family_court_judge_wfp_ricja_d_rice_ghyll"                       
 [89] "family_court_judge_write_in36"                                    "family_court_judge_over_votes37"                                 
 [91] "family_court_judge_under_votes38"                                 "county_legislator_county_legislative_district_5_dem_susan_m_pedo"
 [93] "county_legislator_county_legislative_district_5_write_in39"       "county_legislator_county_legislative_district_5_over_votes40"    
 [95] "county_legislator_county_legislative_district_5_under_votes41"    "cohoes_city_council_member_ward_6_dem_april_m_trudeau"           
 [97] "cohoes_city_council_member_ward_6_con_justin_m_alesio"            "cohoes_city_council_member_ward_6_vfa_april_m_trudeau"           
 [99] "cohoes_city_council_member_ward_6_write_in42"                     "cohoes_city_council_member_ward_6_over_votes43"                  
[101] "cohoes_city_council_member_ward_6_under_votes44"                  "town_justice_town_of_bethlehem_dem_erin_r_lynch"                 
[103] "town_justice_town_of_bethlehem_write_in45"                        "town_justice_town_of_bethlehem_over_votes46"                     
[105] "town_justice_town_of_bethlehem_under_votes47"                     "village_trustee_village_of_green_island_dem_michele_a_heffern"   
[107] "village_trustee_village_of_green_island_dem_richard_r_jones_jr"   "village_trustee_village_of_green_island_dem_joseph_a_liotta_sr"  
[109] "village_trustee_village_of_green_island_write_in48"               "village_trustee_village_of_green_island_over_votes49"            
[111] "village_trustee_village_of_green_island_under_votes50"            "village_trustee_village_of_green_island_dem_barbara_belokopitsky"
[113] "village_trustee_village_of_green_island_write_in51"               "village_trustee_village_of_green_island_over_votes52"            
[115] "village_trustee_village_of_green_island_under_votes53"            "highway_superintendent_town_of_westerlo_dem_james_e_brush"       
[117] "highway_superintendent_town_of_westerlo_rep_david_pecylak"        "highway_superintendent_town_of_westerlo_con_david_pecylak"       
[119] "highway_superintendent_town_of_westerlo_write_in54"               "highway_superintendent_town_of_westerlo_over_votes55"            
[121] "highway_superintendent_town_of_westerlo_under_votes56"            "proposal_one_an_amendment_yes"                                   
[123] "proposal_one_an_amendment_no"                                     "proposal_one_an_amendment_over_votes57"                          
[125] "proposal_one_an_amendment_under_votes58"                          "proposal_two_town_of_bethlehem_yes59"                            
[127] "proposal_two_town_of_bethlehem_no60"                              "proposal_two_town_of_bethlehem_over_votes61"                     
[129] "proposal_two_town_of_bethlehem_under_votes62"