Transport network stats

[Aziz Essouaied]

Hello Stata users, I have this data:

* Example generated by -dataex-. To install: ssc install dataex
clear
input int Code_Ligne str18 Origine str19 Destination str24 Agence int Distance str20 Nom_route
100 "TUNIS"         "GAFSA"            "Agence Gafsa"             371 "TUNIS - NEFTA"       
101 "GAFSA"         "TUNIS"            "Agence Gafsa"             370 "TUNIS - GAFSA"       
102 "NEFTA"         "TUNIS"            "Agence Nefta"             488 "TUNIS - NEFTA"       
103 "SOUSSE"        "ZARZIS"           "Agence Sousse"            404 "SOUSSE - MIDOUNE"    
104 "TUNIS"         "BEN GUERDENE"     "Gare routiere Tunis Sud"  563 "TUNIS - B. GUARDEN"  
105 "SIDI BOUZID"   "TUNIS"            "Agence Sidi Bouzid"       270 "TUNIS - SIDI BOUZID" 
106 "TUNIS"         "SIDI BOUZID"      "Gare routiere Tunis Sud"  291 "TUNIS - TAMEGHZA"    
107 "KASSERINE"     "TUNIS"            "Agence Kasserine"         323 "TUNIS - KASSERINE"   
108 "TUNIS"         "THALA"            "Gare routiere Tunis Nord" 246 "TUNIS - THALA"       
110 "TUNIS"         "JERISSA"          "Gare routiere Tunis Nord" 226 "TUNIS - JERISSA"     
113 "TUNIS"         "THALA"            "Gare routiere Tunis Sud"  246 "TUNIS - THALA"       
114 "TUNIS"         "THALA"            "Gare routiere Tunis Sud"  232 "TUNIS - THALA"       
115 "TUNIS"         "KSOUS"            "Gare routiere Tunis Sud"  207 "TUNIS - GHOMRASSI"   
116 "TUNIS"         "KASSERINE"        "Gare routiere Tunis Sud"  286 "TUNIS - FERIANA"     
117 "TUNIS"         "RDEYEF"           "Gare routiere Tunis Sud"  520 "TUNIS - TAMEGHZA"    
118 "TUNIS"         "ELESSE"           "Gare routiere Tunis Sud"  207 "TUNIS - ELLESSE"     
119 "KEF"           "TUNIS"            "Agence Kef"               172 "TUNIS - THALA"       
120 "TUNIS"         "DAHMANI"          "Gare routiere Tunis Sud"  226 "TUNIS - DEHMANI"     
121 "TUNIS"         "AIN DRAHEM"       "Gare routiere Tunis Nord" 202 "TUNIS - H.BOURGUIBA" 
122 "TUNIS"         "AIN DRAHEM"       "Gare routiere Tunis Sud"  202 "TUNIS - H.BOURGUIBA" 
123 "TUNIS"         "BABBOUCHE"        "Gare routiere Tunis Sud"  212 "TUNIS - H.BOURGUIBA" 
125 "TUNIS"         "TABARKA"          "Gare routiere Tunis Nord" 177 "TUNIS - TABARKA"     
128 "KAIROUAN"      "TUNIS"            "Agence Siliana"           160 "TUNIS - RAS JEDIR"   
129 "MAKTHAR"       "TUNIS"            "Agence Siliana"           165 "TUNIS - FERIANA"     
130 "MAKTHAR"       "TUNIS"            "Agence Siliana"           165 "TUNIS - FERIANA"     
131 "SILIANA"       "TUNIS"            "Agence Siliana"           157 "TUNIS - SILIANA"     
132 "TUNIS"         "OUESLATIA"        "Gare routiere Tunis Sud"  149 "TUNIS - OUESLATIA"   
134 "KASSERINE"     "TUNIS"            "Agence Kasserine"         323 "TUNIS - FERIANA"     
135 "KASSERINE"     "TUNIS"            "Agence Kasserine"         286 "TUNIS - FERIANA"     
136 "KASSERINE"     "TUNIS"            ""                         323 ""                    
138 "KEF"           "TUNIS"            "Agence Kef"               172 "TUNIS - THALA"       
139 "KEF"           "TUNIS"            "Agence Kef"               172 "TUNIS - THALA"       
141 "TUNIS"         "KSNAN"            "Gare routiere Tunis Sud"  232 "TUNIS - K. SENAN"    
142 "TUNIS"         "TOZEUR"           "Gare routiere Tunis Sud"  590 "TUNIS - NEFTA"       
143 "TOZEUR"        "TUNIS"            "Agence Tozeur"            465 "TUNIS - NEFTA"       
145 "ALAA"          "TUNIS"            "Gare routiere Tunis Sud"  200 "TUNIS - EL ALAA"     
146 "TUNIS"         "EL HAMMA"         "Gare routiere Tunis Sud"  471 "TUNIS - EL HAMMA"    
147 "SBIBA"         "TUNIS"            "Gare routiere Tunis Sud"  214 "TUNIS - FERIANA"     
149 "TUNIS"         "TAMEGHZA"         "Gare routiere Tunis Sud"  485 "TUNIS - TAMEGHZA"    
150 "TABARKA"       "TUNIS"            "Agence Tabarka"           177 "TUNIS - TABARKA"     
152 "TABARKA"       "TUNIS"            "Agence Tabarka"           171 "TUNIS - TABARKA"     
154 "BIZERTE"       "SOUSSE"           "Agence Bizerte"           209 "BIZERTE - SOUSSE"    
157 "KAIROUAN"      "TUNIS"            "Agence Kairouan"          160 "KAIROUAN - TUNIS"    
162 "SOUSSE"        "MIDOUN"           "Agence Sousse"            397 "SOUSSE - MIDOUNE"    
164 "SFAX"          "JERBA"            "Agence Sfax"              246 "SFAX - JERBA"        
167 "GASSERINE"     "TUNIS"            "Agence Kasserine"         323 "TUNIS - FERIANA"     
168 "GASSEINE"      "TUNIS"            "Agence Kasserine"         186 "TUNIS - FERIANA"     
169 "TUNIS"         "AIN DRAHAM"       "Gare routiereTtunis Nord" 202 "TUNIS - H.BOURGUIBA" 
173 "JENDOUBA"      "TUNIS"            "Agence Jendouba"          160 "TUNIS - H.BOURGUIBA" 
174 "TUNIS"         "AIN DRAHAM"       "Gare routiere Tunis Nord" 227 "TUNIS - H.BOURGUIBA" 
176 "TUNIS"         "SAKIET"           "Gare routiere Tunis Nord" 214 "TUNIS - SAKIET"      
177 "TUNIS"         "KAIROUAN"         "Gare routiere Tunis Sud"  160 "TUNIS - KAIROUAN"    
178 "TUNIS"         "RAS AJDIR"        "Gare routiere Tunis Sud"  556 "TUNIS - RAS AJDIR"   
179 "TUNIS-BIZERTE" "JERBA"            "Agence Bizerte"           696 "BIZERTE - HOUMT SOUK"
182 "SIDI BOUZID"   "TUNIS"            "Agence Sidi Bouzid"       288 "TUNIS - SIDI BOUZID" 
183 "TOZEUR"        "TUNIS"            "Agence Tozeur"            465 "TUNIS - NEFTA"       
189 "TUNIS"         "TATAOUINE"        "Gare routiere Tunis Sud"  551 "TUNIS - TATAOUINE"   
192 "TUNIS"         "KSNAN"            "Gare routiere Tunis Sud"  232 "TUNIS - K. SENAN"    
193 "DEHMANI"       "TUNIS"            ""                         204 "DEHMANI - TUNIS"     
194 "TUNIS"         "FAWAR"            "Gare routiere Tunis Sud"  605 "TUNIS - REG.MAATOUG" 
204 "TUNIS"         "ALAA"             "Gare routiere Tunis Sud"  200 "TUNIS - EL ALAA"     
206 "TUNIS"         "TABARKA"          "Gare routiere Tunis Sud"  177 "TUNIS - TABARKA"     
209 "TUNIS"         "JERBA"            "Gare routiere Tunis Sud"  502 "TUNIS - JERBA"       
500 "TUNIS"         "JERBA"            ""                         502 "TUNIS - JERBA"       
501 "TUNIS"         "NEFTA"            "Gare routiere Tunis Sud"  487 "TUNIS - NEFTA"       
502 "TUNIS"         "DOUZ"             ""                         590 "TUNIS - DOUZ"        
503 "TUNIS"         "BEN GUERDENE"     ""                         563 "TUNIS - B. GUERDEN"  
504 "TUNIS"         "TATAOUINE"        "Gare routiere Tunis Sud"  551 "TUNIS - TATAOUINE"   
506 "TUNIS"         "ZARZIS"           "Gare routiere Tunis Sud"  509 "TUNIS - ZARZIS"      
507 "TUNIS"         "KBELI"            "Gare routiere Tunis Sud"  547 "TUNIS - SOUK LAHAD"  
508 "TUNIS"         "FERIANA"          "Gare routiere Tunis Sud"  333 "TUNIS - FERIANA"     
509 "TUNIS"         "MEDENINE"         "Gare routiere Tunis Sud"  446 "TUNIS - RAS JEDIR"   
510 "TUNIS"         "MATMATA"          "Gare routiere Tunis Sud"  452 "TUNIS - MATMATA"     
512 "TUNIS"         "JERBA VIA SOUSSE" "Gare routiere Tunis Sud"  541 "TUNIS - JERBA"       
517 "BIZERTE"       "JERBA"            "Agence Bizerte"           606 "BIZERTE - HOUMT SOUK"
518 "TUNIS"         "DHIBA"            "Gare routiere Tunis Sud"  594 "TUNIS - DHIBA"       
651 "TUNIS"         "JERBA"            "Gare routiere Tunis Sud"  487 "TUNIS - JERBA"       
653 "TUNIS"         "TATOUINE"         "Gare routiere Tunis Sud"  487 "TUNIS - TATAOUINE"   
654 "BIZERTE"       "JERBA"            "Agence Bizerte"           598 "BIZERTE - JERBA"     
663 "TUNIS"         "TATOUINE"         "Gare routiere Tunis Sud"  487 "TUNIS - TATAOUINE"   
664 "BIZERTE"       "JERBA"            "Agence Bizerte"           552 "BIZERTE - JERBA"     
end

I would love to have some summary stats about this route network, the first variable is the code of route, the fifth one is the length of each route by kilometeres. As you can see, some routes are repeated since they do take place in different times of the day (one depars in the morning, the other depart at evening for the same destination), as well as the forward and the return directions, that's what explains that some route names and distances are duplicated.
I would love to have summary stats about the maximum route length, the minimum route length as well as the average (Yet, for the average, I don't want to have the duplicated observations included in the calculation, yet I don't want to delete those from the dataset).

Any help please?

[Clyde Schechter]

I'm confused by your data. What exactly identifies a route in your data. I thought it might be Nom_route, but the same Nom_route can show up several times with different origins, different destinations, and different distances. Then I thought perhaps the combination of origin and destination would identify a route. But the same origin-destination pair can show up several times with different distances. So what's going on here? Am I missing something, or is your data messed up?

[Aziz Essouaied]

Hello Clyde Schechter and thanks for the help;

Actually, the "Nom_route" variable is a bit of irrelevant, it repeats the "origin"-"destination" for most of the case. What I'm using to identify a route is its Code, so to answer your question, it is the variable "Code_Ligne" which identifies each route. You might find two routes with differen "Code_Ligne" yet with the same "origin"-"destination", but that's is because it is the same route, only with two different departure times or with what's called in french "sens aller et sens retour" (going to a destination and then getting back from there). But, what identifies the route is its code (the first variable), and its distance in Kms.
What I wanna do is calculate the summary stats, yet for the average figure, I don't wanna calculate the same Distance for two roads having the same "origin"-"destination" two times, I don't wanna calculate the same Distance two times in the average figure.

[Clyde Schechter]

OK, well in that case, your data example has the opposite problem: there are no two observations with the same Code_Ligne. Nevertheless, let's pretend there is. THen to calculate the average without including the same Code_Ligne more than once:

egen code_flag = tag(Code_Ligne)
summ Distance if code_flag

[Aziz Essouaied]

Clyde Schechter You're right, the unique variable for this database is the "Code_Ligne", yet as I said, some route do have different "Code_Ligne", yet they have the same "Distance", the same "Origin-Destination". What I wanna do is calculate the average "Distance of the whole network, yet without calculating the routes who have the same "Distance" two times, since that would give an incorrect value. I just want to clarify that even more.

[Clyde Schechter]

I think you misunderstood my response in #4. In your example data, each Code_Ligne occurs only once--so there are no duplicates to leave out of the calculation. Nevertheless, the code I show in #4 will work in data where there are repeated values of Code_Ligne--and in that situation it will count each of them only once.