Collapse command

[Saini Smriti]

Hello

In my dataset, I have two string variables. I am trying to summarize the number of implementscheme by districts.

implementscheme	district
PumpSet State Plan	Araria
Rotavator State Plan	Patna
Folding LDPE Irrigation Pipe State Plan	Arwal
IrrigationPipe NFSM	Arwal

I am using collapse (count) implementscheme, by(district). I get type mismatch error.
Am I right in using collapse command? or some other command helps here?

Thank You
Smriti

[Nick Cox]

Your data example is difficult to read -- in any future question do please follow http://www.statalist.org/forums/help#stata and use dataex for a readable, unambiguous example -- but the problem is clear enough.

count as astatistic in collapsecounts non-missing values and only applies to numeric variables. Even if string variables were allowed, it would not be what you want, e.g. the count of non-missing values in "a" "a" "a" "b" "b" "c" is 0, as no value is missing. Hence collapse could not possibly give you the data structure you seek, even with an encode of the string variable.

If you want a new dataset, then

contract implementscheme district

should work, while a tabulation is given by

tabulate district  implementscheme

where I am guessing that you have more districts than schemes, hence district is better on the rows.

[Saini Smriti]

* Example generated by -dataex-. To install: ssc install dataex
clear
input str86 implementscheme str18 district
"Animal Deterrent Bio-Acaustic Equipment-Electric Operated(With Solar Panel) State Plan" "Madhubani"        
"Animal Deterrent Bio-Acaustic Equipment-Electric Operated(With Solar Panel) State Plan" "Nalanda"          
"Animal Deterrent Bio-Acaustic Equipment-Electric Operated(With Solar Panel) State Plan" "Sheohar"          
"Animal Deterrent Bio-Acaustic Equipment-Electric Operated(With Solar Panel) State Plan" "Vaishali"         
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Arwal"            
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Begusarai"        
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Bhagalpur"        
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Madhepura"        
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Madhubani"        
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Munger"           
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Muzaffarpur"      
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Nalanda"          
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Pashchim Champaran"
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Patna"            
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Purbi Champaran"  
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Saharsa"          
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Samastipur"       
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Saran"            
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Sheohar"          
"Brush Cutter(1 HP & above petrol engine operated) State Plan"                           "Supaul"           
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Begusarai"        
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Bhagalpur"        
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Khagaria"         
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Madhepura"        
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Pashchim Champaran"
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Saharsa"          
"Brush Cutter(Below 3 BHP petrol driven) State Plan"                                     "Sheohar"          
"Cage Wheel(one pair) State Plan"                                                        "Banka"            
"Cage Wheel(one pair) State Plan"                                                        "Nalanda"          
"Cage Wheel(one pair) State Plan"                                                        "Patna"            
"Cage Wheel(one pair) State Plan"                                                        "Saharsa"          
"Cage Wheel(one pair) State Plan"                                                        "Sheikhpura"       
"Cage Wheel(one pair) State Plan"                                                        "Supaul"           
"Chaff Cutter Manual State Plan"                                                         "Araria"           
"Chaff Cutter Manual State Plan"                                                         "Arwal"            
"Chaff Cutter Manual State Plan"                                                         "Aurangabad"       
"Chaff Cutter Manual State Plan"                                                         "Banka"            
"Chaff Cutter Manual State Plan"                                                         "Begusarai"        
"Chaff Cutter Manual State Plan"                                                         "Bhagalpur"        
"Chaff Cutter Manual State Plan"                                                         "Bhojpur"          
"Chaff Cutter Manual State Plan"                                                         "Buxar"            
"Chaff Cutter Manual State Plan"                                                         "Darbhanga"        
"Chaff Cutter Manual State Plan"                                                         "Gaya"             
"Chaff Cutter Manual State Plan"                                                         "Gopalganj"        
"Chaff Cutter Manual State Plan"                                                         "Jamui"            
"Chaff Cutter Manual State Plan"                                                         "Jehanabad"        
"Chaff Cutter Manual State Plan"                                                         "Kaimur (Bhabua)"  
"Chaff Cutter Manual State Plan"                                                         "Katihar"          
"Chaff Cutter Manual State Plan"                                                         "Khagaria"         
"Chaff Cutter Manual State Plan"                                                         "Kishanganj"       
"Chaff Cutter Manual State Plan"                                                         "Lakhisarai"       
"Chaff Cutter Manual State Plan"                                                         "Madhepura"        
"Chaff Cutter Manual State Plan"                                                         "Madhubani"        
"Chaff Cutter Manual State Plan"                                                         "Munger"           
"Chaff Cutter Manual State Plan"                                                         "Muzaffarpur"      
"Chaff Cutter Manual State Plan"                                                         "Nalanda"          
"Chaff Cutter Manual State Plan"                                                         "Nawada"           
"Chaff Cutter Manual State Plan"                                                         "Pashchim Champaran"
"Chaff Cutter Manual State Plan"                                                         "Patna"            
"Chaff Cutter Manual State Plan"                                                         "Purbi Champaran"  
"Chaff Cutter Manual State Plan"                                                         "Purnia"           
"Chaff Cutter Manual State Plan"                                                         "Rohtas"           
"Chaff Cutter Manual State Plan"                                                         "Saharsa"          
"Chaff Cutter Manual State Plan"                                                         "Samastipur"       
"Chaff Cutter Manual State Plan"                                                         "Saran"            
"Chaff Cutter Manual State Plan"                                                         "Sheikhpura"       
"Chaff Cutter Manual State Plan"                                                         "Sheohar"          
"Chaff Cutter Manual State Plan"                                                         "Sitamarhi"        
"Chaff Cutter Manual State Plan"                                                         "Siwan"            
"Chaff Cutter Manual State Plan"                                                         "Supaul"           
"Chaff Cutter Manual State Plan"                                                         "Vaishali"         
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Araria"           
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Arwal"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Banka"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Begusarai"        
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Bhagalpur"        
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Gaya"             
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Gopalganj"        
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Jamui"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Kaimur (Bhabua)"  
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Khagaria"         
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Lakhisarai"       
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Madhepura"        
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Madhubani"        
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Munger"           
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Muzaffarpur"      
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Nalanda"          
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Pashchim Champaran"
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Patna"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Purbi Champaran"  
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Purnia"           
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Saharsa"          
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Samastipur"       
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Saran"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Sheikhpura"       
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Sheohar"          
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Siwan"            
"Chaff Cutter(Mannual Heavy Duty)-3 Roller, Shuking Type State Plan"                     "Supaul"           
"Chaff Cutter(Manual)-2 Roller,Non-Shuking Type State Plan"                              "Araria"           
"Chaff Cutter(Manual)-2 Roller,Non-Shuking Type State Plan"                              "Arwal"            
end

[Saini Smriti]

Hi Nick

This is how the data looks. I was not trying to create a new dataset but was trying to understand the frequency of implementscheme by district.

The contract command works perfectly. Tabulation can not since there are too many values.

Thank You

[Nick Cox]

OK. In #2 I exaggerated in saying that

collapse could not possibly give you the data structure you seek

because this simple trick gets you counts:

gen count = 1 
collapse (sum) count, by(implementscheme district)

count is a poor name when its values are all 1, but once collapse has done its work, it is exactly right. There is no objection to string variables as arguments for by().

[Saini Smriti]

Thank You. That worked.