R help - Feb 2010 - Finding ranges on a per-row basis from several objects

Dear all,

I'm attemping to find the overall range of values from column 5 of a series
of data frames, on a per-row basis, and assign the results to a new object. At
present, I'm only able to receive the overall range of all values, whereas
I'm intending to get the results of the range for each corresponding row.
This is what I have so far:

for (i in seq(nrow(dframe[1])))

??? range_models <- rbind(range(c(dframe1[i,5]), range(dframe2[i,5]),
range(dframe3[i,5]), range(dframe4[i,5]), range(dframe5[i,5]),
range(dframe6[i,5])))
??? }

If it's of any help, the structure of each of the data frames is:

    
> str(dframe1)
'data.frame':??? 61538 obs. of? 6 variables:
?$ Latitude??? : num? -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25
-0.25 ...
?$ Longitude?? : num? -48.8 -49.2 -49.8 -50.2 -50.8 ...
?$ Runoff_fut? : num? 1549 1335 1254 1111 1066 ...
?$ Runoff_bline: num? 1877 1719 1550 1438 1362 ...
?$ Difference? : num? -328 -383 -296 -327 -297 ...
?$ PerctDiff?? : num? -17.5 -22.3 -19.1 -22.7 -21.8 ...


So, just to clarify, I'm trying to find the range of values for row 1 based
on dframe1 through to dframe6, then row 2,? row 3 etc etc. and put the range
results for each row into a new object of equal row number to the dframe
objects.

Many thanks for any help offered,

Steve

 		 	   		  
_________________________________________________________________
Got a cool Hotmail story? Tell us now

On 02/05/2010 09:21 PM, Steve Murray wrote:
>
> Dear all,
>
> I'm attemping to find the overall range of values from column 5 of a
series of data frames, on a per-row basis, and assign the results to a new
object. At present, I'm only able to receive the overall range of all
values, whereas I'm intending to get the results of the range for each
corresponding row. This is what I have so far:
>
> for (i in seq(nrow(dframe[1])))
>
>      range_models<- rbind(range(c(dframe1[i,5]), range(dframe2[i,5]),
range(dframe3[i,5]), range(dframe4[i,5]), range(dframe5[i,5]),
range(dframe6[i,5])))
>      }
>
> If it's of any help, the structure of each of the data frames is:
>
>
>
>> str(dframe1)
> 'data.frame':    61538 obs. of  6 variables:
>   $ Latitude    : num  -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25 -0.25
-0.25 -0.25 ...
>   $ Longitude   : num  -48.8 -49.2 -49.8 -50.2 -50.8 ...
>   $ Runoff_fut  : num  1549 1335 1254 1111 1066 ...
>   $ Runoff_bline: num  1877 1719 1550 1438 1362 ...
>   $ Difference  : num  -328 -383 -296 -327 -297 ...
>   $ PerctDiff   : num  -17.5 -22.3 -19.1 -22.7 -21.8 ...
>
>
> So, just to clarify, I'm trying to find the range of values for row 1
based on dframe1 through to dframe6, then row 2,  row 3 etc etc. and put the
range results for each row into a new object of equal row number to the dframe
objects.
>
Hi Steve,
If I get the idea, you want to get the ranges of "Difference" across
the
data frames a row at a time. I think this will work:

combdframe<-as.matrix(cbind(dframe1$Difference,dframe2$Difference,
  dframe3$Difference,dframe4$Difference,
  dframe5$Difference,dframe6$Difference))
apply(combdframe,1,range)

You may have to add "na.rm=TRUE" if there are NAs.

Jim