Problem with a time variable: How can I extract values in a certain range please?

[Michael Duarte Goncalves]

Hi everyone, I have a variable of type double %tC, and I want to create a new variable that takes only values from 9 p.m. to 6:59 a.m.
Then, I want to do -replace- condition with this new variable, but only for observations that have a "start-time" between 7:00 a.m. to 8:59 p.m.

Could anyone help me please:

Here's one of my code attempts:

gen taxi_trips_costs = .
label var taxi_trips_costs "Cost of a Taxi Trip, in €"

replace taxi_trips_costs = 30 if (origin_barrio == "Aeropuerto" & destination_madridcentral == 1) | (origin_madridcentral == 1 & destination_barrio == "Aeropuerto")

replace taxi_trips_costs = 2.4 + 1.05 * DISTANCIA_VIAJE if (origin_barrio != "Aeropuerto" & origin_madridcentral == 0) | (destination_barrio!= "Aeropuerto" & destination_madridcentral == 0) & start_hour >= 7 & start_hour <= 21

replace taxi_trips_costs = 2.9 + 1.2 * DISTANCIA_VIAJE if (origin_barrio != "Aeropuerto" & origin_madridcentral == 0) | (destination_barrio != "Aeropuerto" & destination == 0) & (start_hour >= 21 & start_min >=0 | start_hour < 7)

Here is a dataex example:

[CODE]

* Example generated by -dataex-. For more info, type help dataex
clear
input str47 origin_barrio long origin_madridcentral str47 destination_barrio long destination_madridcentral byte(start_hour start_minute) double start_time
"Valverde"             0 "Valverde"                       0 15  5 54300000
"Aluche"               0 "Aluche"                         0  8 15 29700000
"Legazpi"              0 "Delicias"                       0 12  0 43200000
"Almenara"             0 "Almenara"                       0  9  0 32400000
"Entrevías"           0 "Entrevías"                     0  9  0 32400000
"Aluche"               0 "Aluche"                         0 20 30 73800000
"Opañel"              0 "Abrantes"                       0 20 30 73800000
"Entrevías"           0 "Entrevías"                     0 11 30 41400000
"Pilar"                0 "Pilar"                          0 17  0 61200000
"Pilar"                0 "Valverde"                       0 16  0 57600000
"Los Ángeles"         0 "Villaverde Alto"                0  7 30 27000000
"El Viso"              0 "Recoletos"                      0  8 45 31500000
"Apostol Santiago"     0 "Apostol Santiago"               0 14 45 53100000
"Moscardó"            0 "Imperial"                       0 18  0 64800000
"Recoletos"            0 "Palomeras Bajas"                0 14  0 50400000
"Atocha"               0 "Palos de Moguer"                0 10 30 37800000
"Buenavista"           0 "Cuatro Vientos"                 0  8 53 31980000
"Argüelles"           0 "Numancia"                       0 16  0 57600000
"Embajadores"          1 "Cortes"                         1 10 25 37500000
"Quintana"             0 "Hispanoamérica"                0  8 10 29400000
"Palacio"              1 "Argüelles"                     0 11 40 42000000
"Embajadores"          1 "Embajadores"                    1 22 30 81000000
"Numancia"             0 "Portazgo"                       0 17  2 61320000
"Opañel"              0 "Comillas"                       0 14 20 51600000
"Moscardó"            0 "Vista Alegre"                   0 12  0 43200000
"Puerta del Ángel"    0 "Lucero"                         0 14  0 50400000
"Rosas"                0 "Arcos"                          0 19 54 71640000
"Piovera"              0 "San Pascual"                    0 18 35 66900000
"Ensanche de Vallecas" 0 "Ensanche de Vallecas"           0  9  0 32400000
"El Goloso"            0 "Palos de Moguer"                0 17  0 61200000
"Castilla"             0 "Ciudad Jardín"                 0 17 30 63000000
"Castellana"           0 "Lista"                          0 16 55 60900000
"Aravaca"              0 "Almagro"                        0 12  0 43200000
"Villaverde Alto"      0 "Villaverde Alto"                0  9 38 34680000
"Águilas"             0 "Águilas"                       0  9 40 34800000
"Legazpi"              0 "Pacífico"                      0 16  0 57600000
"Puerta Bonita"        0 "Universidad"                    1 12  0 43200000
"Valdemarín"          0 "Valdemarín"                    0  9  9 32940000
"Delicias"             0 "Embajadores"                    1 17 31 63060000
"Guindalera"           0 "Guindalera"                     0 11  0 39600000
"Rosas"                0 "Arcos"                          0 16 45 60300000
"San Juan Bautista"    0 "Almagro"                        1 10 30 37800000
"El Viso"              0 "Timón"                         0 16 40 60000000
"Guindalera"           0 "Pueblo Nuevo"                   0 14 15 51300000
"Ciudad Jardín"       0 "Cortes"                         1 20 45 74700000
"Concepción"          0 "Concepción"                    0 16 45 60300000
"La Paz"               0 "Pilar"                          0 20 55 75300000
"Guindalera"           0 "Guindalera"                     0 13 20 48000000
"Valderrivas"          0 "Casco Histórico de Vicálvaro" 0  9 30 34200000
"Cuatro Caminos"       0 "Cuatro Caminos"                 0 16 30 59400000
"Puerta Bonita"        0 "Rios Rosas"                     0 15  0 54000000
"Orcasitas"            0 "Orcasitas"                      0 12 57 46620000
"San Cristóbal"       0 "Acacias"                        0  8 15 29700000
"Mirasierra"           0 "Peñagrande"                    0 22  0 79200000
"Legazpi"              0 "Butarque"                       0 19  0 68400000
"Media Legua"          0 "Castellana"                     0 10 50 39000000
"Palomeras Sureste"    0 "Palomeras Sureste"              0 19 30 70200000
"San Juan Bautista"    0 "Valdefuentes"                   0  8 55 32100000
"Justicia"             1 "Trafalgar"                      0 17  0 61200000
"Universidad"          1 "Valverde"                       0 22  0 79200000
"Mirasierra"           0 "Mirasierra"                     0  8 55 32100000
"Costillares"          0 "Apostol Santiago"               0 17  6 61560000
"El Viso"              0 "Arcos"                          0 15  0 54000000
"Cuatro Vientos"       0 "Cuatro Vientos"                 0 17 20 62400000
"Numancia"             0 "Numancia"                       0 18 30 66600000
"Goya"                 0 "Goya"                           0 12 30 45000000
"Portazgo"             0 "Palomeras Bajas"                0  7 30 27000000
"Ibiza"                0 "Palacio"                        1  8 41 31260000
"Ibiza"                0 "Ibiza"                          0 19 32 70320000
"Horcajo"              0 "Valdebernardo"                  0 19 15 69300000
"Pacífico"            0 "Casco Histórico de Vallecas"   0 17  0 61200000
"Puerta del Ángel"    0 "Puerta del Ángel"              0  8 50 31800000
"Numancia"             0 "Numancia"                       0  8  0 28800000
"Palomeras Bajas"      0 "Portazgo"                       0 15  0 54000000
"Vinateros"            0 "Vinateros"                      0 11  0 39600000
"Vista Alegre"         0 "Legazpi"                        0 18 30 66600000
"Valverde"             0 "Salvador"                       0  9 50 35400000
"Arapiles"             0 "Cortes"                         1 19 15 69300000
"Bellas Vistas"        0 "Vallehermoso"                   0 13 40 49200000
"Los Ángeles"         0 "San Fermín"                    0 16 30 59400000
"Rosas"                0 "Rosas"                          0  8  0 28800000
"Almenara"             0 "Adelfas"                        0 17  0 61200000
"Palos de Moguer"      0 "Delicias"                       0 19 45 71100000
"Cuatro Caminos"       0 "Valverde"                       0 18 50 67800000
"Cármenes"            0 "Lucero"                         0  8 30 30600000
"Fuente del Berro"     0 "Fuente del Berro"               0 20  0 72000000
"Valverde"             0 "Valdebernardo"                  0 16  0 57600000
"Sol"                  1 "Delicias"                       0 21 30 77400000
"San Isidro"           0 "San Isidro"                     0 13 45 49500000
"Ciudad Universitaria" 0 "Puerta Bonita"                  0 15  0 54000000
"Numancia"             0 "Numancia"                       0 21 20 76800000
"Alameda de Osuna"     0 "Alameda de Osuna"               0 13 40 49200000
"Los Rosales"          0 "Vallehermoso"                   0 18  0 64800000
"Ensanche de Vallecas" 0 "Marroquina"                     0 20 30 73800000
"Numancia"             0 "Casco Histórico de Vallecas"   0 14 40 52800000
"Ciudad Universitaria" 0 "Peñagrande"                    0 16 38 59880000
"Palacio"              1 "Almenara"                       0 19  0 68400000
"Nueva España"        0 "Hispanoamérica"                0 19  0 68400000
"Imperial"             0 "Opañel"                        0 12 30 45000000
"Guindalera"           0 "Lista"                          0 18  0 64800000
end
format %tC start_time
label values origin_madridcentral madcent
label values destination_madridcentral madcent
label def madcent 0 "Rest of Madrid", modify
label def madcent 1 "Madrid Central", modify

The part of "start_time" variable 01jan1960 is a mistake. We can just drop it please.

Thank you in advance.

Best,

Michael

[Clyde Schechter]

The part of "start_time" variable 01jan1960 is a mistake. We can just drop it please.

No, it's not a mistake; you can't drop it and shouldn't try to. There is no pure time variable in Stata. There are datetime variables. To represent a time of day, you must include a date as well. The default date is 01jan1960. If it displeases you to see 01jan1960 there, you can suppress its appearance with

format start_time %tCHH:MM

But this does not actually change the value of start_time from Stata's perspective. (And, again, you shouldn't. The variable is correctly constructed as is.)

With regard to your taxi_trips_cost variable, the code you show fails with your data example because it refers to a variable, DISTANCIA_VIAJE, which does not exist, and because the final-replace refers to a variable destination--and Stata cannot figureout whether you mean destination_madridcentral or destination_barrio. But once you fix those problems, it all seems to run without errors and produces reasonable appearing results. So what exactly is the question?

[Michael Duarte Goncalves]

Dear Clyde Schechter:

Thank you very much for your suggestion. I didn't know I should not drop it.

Thanks for your suggestion, I clean up some data, and all works well.

Thank you for your time.

Best regards,

Michael