A.K. Wonderful - thank you. The last set of code using sapply(),
seq_along(), and get() worked like a charm and was what I was missing.
Brian
Brian S. Cade, PhD
U. S. Geological Survey
Fort Collins Science Center
2150 Centre Ave., Bldg. C
Fort Collins, CO 80526-8818
email: ca...@usgs.gov <brian_c...@usgs.gov>
tel: 970 226-9326
On Tue, Apr 15, 2014 at 8:11 PM, arun <smartpink...@yahoo.com> wrote:
> Hi,
>
> If the two pairs of matrices are in a list:
> set.seed(42)
> lst1 <- lapply(1:11, function(x) matrix(sample(40, 20, replace=TRUE), 5,4))
>
> names(lst1) <- paste0("gs", paste0("4.",seq(0,100,by=10)))
> set.seed(585)
>
> lst2 <- lapply(1:11, function(x) matrix(sample(40, 20, replace=TRUE), 5,4))
>
> names(lst2) <- paste0("ps", paste0("1.",seq(0,100,by=10)))
> mean.comb <- data.frame(simulation=0:10,
> mean.horses.removed=sapply(seq_along(lst1),function(i)
> mean(rowSums(lst1[[i]]*lst2[[i]]))))
>
> #or
>
> # if the datasets are standalone with no particular order
> #just for demonstration
> attach(lst1)
>
> attach(lst2)
>
> vec1 <- sample(paste0("gs", paste0("4.",seq(0,100,by=10))), 11,
> replace=FALSE)
> vec2 <- sample(paste0("ps", paste0("1.",seq(0,100,by=10))), 11,
> replace=FALSE)
>
> vec1New <- vec1[order(as.numeric(gsub(".*\\.","",vec1)))]
>
> vec2New <- vec2[order(as.numeric(gsub(".*\\.","",vec2)))]
>
> mean.comb2 <- data.frame(simulation=0:10,
> mean.horses.removed=sapply(seq_along(vec1New),function(i)
> mean(rowSums(get(vec1New[i])* get(vec2New[i])))))
> identical(mean.comb,mean.comb2)
>
> #[1] TRUE
>
>
> A.K.
>
>
>
>
>
> On Tuesday, April 15, 2014 4:30 PM, "Cade, Brian" <ca...@usgs.gov> wrote:
> So I know I must be missing something simple and obvious for the following
> data manipulation where I have (in this example) 11 pairs of matrices
> (gs4.0 to gs4.100 and ps1.0 to ps1.100) from some population simulations
> (all with same dimensions) where I want to get some summary statistics on
> the products of the cells in a pair (e.g., gs4.0 * ps1.0). The code I
> wrote below works fine, but it seems like there ought to be a simple way to
> index the extensions on the names (.0 to .100) in a for loop to simplify
> this code greatly. I've spent some time trying various things using
> paste() and assign() and have had no success.
>
> mean.comb <- as.matrix(0:10,nrow = 11, ncol=1)
> mean.comb <- cbind(mean.comb,0)
>
> ###to see list of files created
> gs4files <- ls(pattern="gs4.*0")
> ps1files <- ls(pattern="ps1.*0")
>
> mean.comb[1,2] <- mean(apply(gs4.0 * ps1.0,1,sum))
> mean.comb[2,2] <- mean(apply(gs4.10 * ps1.10,1,sum))
> mean.comb[3,2] <- mean(apply(gs4.20 * ps1.20,1,sum))
> mean.comb[4,2] <- mean(apply(gs4.30 * ps1.30,1,sum))
> mean.comb[5,2] <- mean(apply(gs4.40 * ps1.40,1,sum))
> mean.comb[6,2] <- mean(apply(gs4.50 * ps1.50,1,sum))
> mean.comb[7,2] <- mean(apply(gs4.60 * ps1.60,1,sum))
> mean.comb[8,2] <- mean(apply(gs4.70 * ps1.70,1,sum))
> mean.comb[9,2] <- mean(apply(gs4.80 * ps1.80,1,sum))
> mean.comb[10,2] <- mean(apply(gs4.90 * ps1.90,1,sum))
> mean.comb[11,2] <- mean(apply(gs4.100 * ps1.100,1,sum))
>
> mean.comb<- data.frame(mean.comb)
> colnames(mean.comb) <- c("simulation", "mean.horses.removed")
>
>
> Brian
>
> Brian S. Cade, PhD
>
> U. S. Geological Survey
> Fort Collins Science Center
> 2150 Centre Ave., Bldg. C
> Fort Collins, CO 80526-8818
>
> email: ca...@usgs.gov <brian_c...@usgs.gov>
> tel: 970 226-9326
>
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>
> ______________________________________________
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> 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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