Just call 'round' on your results then at your desired number of digits. On Tue, May 9, 2017 at 10:09 AM, lily li <chocol...@gmail.com> wrote:
> Thanks very much, it works. But how to round the values to have only 1 > decimal digit or 2 decimal digits? I think by dividing, the values are > double type now. Thanks again. > > > On Tue, May 9, 2017 at 9:04 AM, Charles Determan <cdeterma...@gmail.com> > wrote: > >> If you want the mean of each element across you list of matrices the >> following should provide what you are looking for where Reduce sums all >> your matrix elements across matrices and the simply divided my the number >> of matrices for the element-wise mean. >> >> Reduce(`+`, mylist)/length(mylist) >> >> Regards, >> Charles >> >> On Tue, May 9, 2017 at 9:52 AM, lily li <chocol...@gmail.com> wrote: >> >>> I meant for each cell, it takes the average from other dataframes at the >>> same cell. I don't know how to deal with row names and col names though, >>> so >>> it has the error message. >>> >>> On Tue, May 9, 2017 at 8:50 AM, Doran, Harold <hdo...@air.org> wrote: >>> >>> > It’s not clear to me what your actual structure is. Can you provide >>> > str(object)? Assuming it is a list, and you want the mean over all >>> cells or >>> > columns, you might want like this: >>> > >>> > >>> > >>> > myData <- vector("list", 3) >>> > >>> > >>> > >>> > for(i in 1:3){ >>> > >>> > myData[[i]] <- matrix(rnorm(100), 10, 10) >>> > >>> > } >>> > >>> > >>> > >>> > ### mean over all cells >>> > >>> > sapply(myData, function(x) mean(x)) >>> > >>> > >>> > >>> > ### mean over all columns >>> > >>> > sapply(myData, function(x) colMeans(x)) >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > *From:* lily li [mailto:chocol...@gmail.com] >>> > *Sent:* Tuesday, May 09, 2017 10:44 AM >>> > *To:* Doran, Harold <hdo...@air.org> >>> > *Cc:* R mailing list <r-help@r-project.org> >>> > *Subject:* Re: [R] About calculating average values from several >>> matrices >>> >>> > >>> > >>> > >>> > I'm trying to get a new dataframe or whatever to call, which has the >>> same >>> > structure with each file as listed above. For each cell in the new >>> > dataframe or the new file, it is the average value from former >>> dataframes >>> > at the same location. Thanks. >>> > >>> > >>> > >>> > On Tue, May 9, 2017 at 8:41 AM, Doran, Harold <hdo...@air.org> wrote: >>> > >>> > Are you trying to take the mean over all cells, or over rows/columns >>> > within each dataframe. Also, are these different dataframes stored >>> within a >>> > list or are they standalone? >>> > >>> > >>> > >>> > >>> > -----Original Message----- >>> > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of lily >>> li >>> > Sent: Tuesday, May 09, 2017 10:39 AM >>> > To: R mailing list <r-help@r-project.org> >>> > Subject: [R] About calculating average values from several matrices >>> > >>> > Hi R users, >>> > >>> > I have a question about manipulating the data. >>> > For example, there are several such data frames or matrices, and I >>> want to >>> > calculate the average value from all the data frames or matrices. How >>> to do >>> > it? Also, should I convert them to data frame or matrix first? Right >>> now, >>> > when I use typeof() function, each one is a list. >>> > >>> > file1 >>> > jan feb mar apr may jun jul aug sep oct >>> nov >>> > >>> > app1 1.1 1.2 0.8 0.9 1.3 1.5 2.2 3.2 3.0 1.2 >>> 1.1 >>> > app2 3.1 3.2 2.8 2.5 2.3 2.5 3.2 3.0 2.9 1.8 >>> 1.8 >>> > app3 5.1 5.2 3.8 4.9 5.3 5.5 5.2 4.2 5.0 4.2 >>> 4.1 >>> > >>> > file2 >>> > jan feb mar apr may jun jul aug sep oct >>> nov >>> > >>> > app1 1.9 1.5 0.5 0.9 1.2 1.8 2.5 3.7 3.2 1.5 >>> 1.6 >>> > app2 3.5 3.7 2.3 2.2 2.5 2.0 3.6 3.2 2.8 1.2 >>> 1.4 >>> > app3 5.5 5.0 3.5 4.4 5.4 5.6 5.3 4.4 5.2 4.3 >>> 4.2 >>> > >>> > file3 has the similar structure and values... >>> > >>> > There are eight such files, and when I use the function mean(file1, >>> file2, >>> > file3, ..., file8), it returns the error below. Thanks for your help. >>> > >>> > Warning message: >>> > In mean.default(file1, file2, file3, file4, file5, file6, file7, : >>> > argument is not numeric or logical: returning NA >>> > >>> > [[alternative HTML version deleted]] >>> > >>> > ______________________________________________ >>> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> > 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. >>> > >>> > >>> > >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> https://stat.ethz.ch/mailman/listinfo/r-help >>> PLEASE do read the posting guide http://www.R-project.org/posti >>> ng-guide.html >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.