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PDXRugger

2008-Nov-21 18:38 UTC

[R] Conditionally Removing data from a vector

I am having trouble removing entries from a vector based on the value of the
vector and another object value.  It works in my pseudo test run:

DEV=400	
#Y
CANDS=c(100:105)
#Z
DEVS=c(120,220,320,420,520)
	if(DEV>DEVS)
		 (CANDS=CANDS[which(DEV<DEVS)]) 
     CANDS DEVS
[1,]   100  120
[2,]   101  220
[3,]   102  320
[4,]   103  420
[5,]   104  520
[6,]   105  620

So the result  CANDS is 103, 104 and 105 b/c the corresponding DEVS are
larger than the DEV(400 in this case).
Now i am trying to implement this into my working code but it doenst seem to
work.  

#Loads TAZ and corresponding vacant acres data
TAZ_VAC_ACRES= read.csv(file="I:/Research.....csv",header=TRUE);

#Converts vacant acres by TAZ to vacant square footage by TAZ
TAZ_VAC_FEET=cbind(TAZ_VAC_ACRES[1],TAZ_VAC_ACRES[2]*43560)

#Creates test Candidates Vector
Candidates=c(100,101,102,103,104,105)

#Creates object equaling the number of candidate TAZs from the main script
Location Choice Model
NumCands1=length(Candidates)

Dev..At=9999999

	for(i in 1:NumCands1){	
	
	#Renames each candidate TAZ to function variable
	Loc_Mod_TAZ=Candidates[i]

	#Converts Development size from main script to Development density function
format
	Dev_Size=Dev..At

	#Determines vacant square feet by TAZ 
	TAZDetermine_FEET=TAZ_VAC_FEET[TAZ_VAC_FEET$TAZ==Loc_Mod_TAZ,2]
	
			#Determines if the Candidate TAZs have sufficient vacancy and creates
vector with TAZs that can accomadate development
			if(Dev_Size>TAZDetermine_FEET)
				(Candidates=Candidates[which(Dev_Size>TAZDetermine_FEET)])

	}

So basically i am starting out with a list of CAndidate TAZs and i want to
remove the TAZS that are not big enough to accomadate the
Development(Dev..At).  My test code works but again i cant get it to run in
my workiong code.  Anything stupid im missing or maybe a better approach
than the "which" function.  Remove only seem useful for entire objects
so
not sure what else would work. Thanks guys and gals

Cheers, 
JR

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Philipp Pagel

2008-Nov-21 19:24 UTC

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[R] Conditionally Removing data from a vector

> I am having trouble removing entries from a vector based on the value of
the
> vector and another object value.  It works in my pseudo test run:
> 
> DEV=400	
> #Y
> CANDS=c(100:105)
> #Z
> DEVS=c(120,220,320,420,520)
> 	if(DEV>DEVS)
> 		 (CANDS=CANDS[which(DEV<DEVS)]) 
>      CANDS DEVS
> [1,]   100  120
> [2,]   101  220
> [3,]   102  320
> [4,]   103  420
> [5,]   104  520
> [6,]   105  620

The above code does not produce the output you show when I
paste it into R. It would be highly desirable to have a short,
documented, working example...
> So the result  CANDS is 103, 104 and 105 b/c the corresponding DEVS are
> larger than the DEV(400 in this case).
How do they correspond? Do you mean they are both columns of a
data.frame as your example output suggests? But CANDS and DEVS
are of differnt length, so this is probably not what you meant.
Finally, your code seems to indicate that you want all elements
of CANDS for which the corresponding (?) value of DEVS is less
than threshold DEV, but only if DEV>DEVS. The latter produces a
warning, as you are comparing a single value to a vector of 5,
which is most likely not what you want. At this point my
confusion is perfect and I give up. 

I think you need to give us a better explanantion of what data
you have and what exactly you want to accomplish.

cu
	Philipp


-- 
Dr. Philipp Pagel
Lehrstuhl f?r Genomorientierte Bioinformatik
Technische Universit?t M?nchen
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany
http://mips.gsf.de/staff/pagel

PDXRugger

2008-Nov-21 19:45 UTC

head link

[R] Conditionally Removing data from a vector

I greatly apoligize, clear in my own mind, just didnt explain well enough. 
DEVS should equal 6 values the last being 620, like the data frame:
           CANDS DEVS> [1,]   100  120
> [2,]   101  220
> [3,]   102  320
> [4,]   103  420
> [5,]   104  520
> [6,]   105  620
And yes, my first question is do i need a "if" statement at all as the
which
command seems to do the same thing.  IN my working code i start with a
vector of Candidates, a process occurs that looks up a value associated with
each of those Candidates.  If the corresponding value is equal to or larger
than the starting value, in the test case the DEV value, then that Candidate
is kept and the next Candidate is analyzed.  The final product is a new
vector of Candidates, those that are equal to or larger than the DEV value. 
Hope i didnt further the perfection of your confucion.  Thanks for your
time, let me know if i need to ask a better question

Cheers, 
JR 


Philipp Pagel-5 wrote:> 
> 
>> I am having trouble removing entries from a vector based on the value
of
>> the
>> vector and another object value.  It works in my pseudo test run:
>> 
>> DEV=400	
>> #Y
>> CANDS=c(100:105)
>> #Z
>> DEVS=c(120,220,320,420,520)
>> 	if(DEV>DEVS)
>> 		 (CANDS=CANDS[which(DEV<DEVS)]) 
>>      CANDS DEVS
>> [1,]   100  120
>> [2,]   101  220
>> [3,]   102  320
>> [4,]   103  420
>> [5,]   104  520
>> [6,]   105  620
> 
> 
> The above code does not produce the output you show when I
> paste it into R. It would be highly desirable to have a short,
> documented, working example...
> 
>> So the result  CANDS is 103, 104 and 105 b/c the corresponding DEVS are
>> larger than the DEV(400 in this case).
> 
> How do they correspond? Do you mean they are both columns of a
> data.frame as your example output suggests? But CANDS and DEVS
> are of differnt length, so this is probably not what you meant.
> Finally, your code seems to indicate that you want all elements
> of CANDS for which the corresponding (?) value of DEVS is less
> than threshold DEV, but only if DEV>DEVS. The latter produces a
> warning, as you are comparing a single value to a vector of 5,
> which is most likely not what you want. At this point my
> confusion is perfect and I give up. 
> 
> I think you need to give us a better explanantion of what data
> you have and what exactly you want to accomplish.
> 
> cu
> 	Philipp
> 
> 
> -- 
> Dr. Philipp Pagel
> Lehrstuhl f?r Genomorientierte Bioinformatik
> Technische Universit?t M?nchen
> Wissenschaftszentrum Weihenstephan
> 85350 Freising, Germany
> http://mips.gsf.de/staff/pagel
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 
> 
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R help - Nov 2008 - Conditionally Removing data from a vector

[R] Conditionally Removing data from a vector

[R] Conditionally Removing data from a vector

[R] Conditionally Removing data from a vector