[R] About calculating average values from several matrices

[lily li]

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 <HDoran at 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:chocold12 at gmail.com]
> *Sent:* Tuesday, May 09, 2017 10:44 AM
> *To:* Doran, Harold <HDoran at air.org>
> *Cc:* R mailing list <r-help at 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 <HDoran at 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-bounces at r-project.org] On Behalf Of lily li
> Sent: Tuesday, May 09, 2017 10:39 AM
> To: R mailing list <r-help at 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]]
>
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