R help - Feb 2016 - Matrix summary

hi all,

I have  a square matrix (1000 by 1000),
1. I want calculate  mean,  min and max values for each column and row.

2, I want pick the  coordinate value of the matrix that has the max
and min value for each row and column.
This an example 4 by 4 square matrix


                                              Mean    Min    Max
            117   12    13     21    40.75       12    117
             21    32    11       1     16.25       1       32
             65    43    23       7      34.5        7       65
             58    61    78     95        73        58      95
Mean    65    25    37   31.25
Min        21    12    11    1
Max     117    61    78    95


Thank you

Hi Ashta,
Surely you are aware of the "apply" family of functions that return
the
numbers you want:

ashmat<-matrix(c(117,12,13,21,21,32,11,1,65,43,23,7,58,61,78,95 ),
 nrow=4,byrow=TRUE)
apply(ashmat,2,mean)
[1] 65.25 37.00 31.25 31.00
apply(ashmat,1,which.max)
[1] 1 2 1 4

Jim


On Sat, Feb 13, 2016 at 3:04 PM, Ashta <sewashm at gmail.com> wrote:
> hi all,
>
> I have  a square matrix (1000 by 1000),
> 1. I want calculate  mean,  min and max values for each column and row.
>
> 2, I want pick the  coordinate value of the matrix that has the max
> and min value for each row and column.
> This an example 4 by 4 square matrix
>
>
>                                               Mean    Min    Max
>             117   12    13     21    40.75       12    117
>              21    32    11       1     16.25       1       32
>              65    43    23       7      34.5        7       65
>              58    61    78     95        73        58      95
> Mean    65    25    37   31.25
> Min        21    12    11    1
> Max     117    61    78    95
>
>
> Thank you
>
> ______________________________________________
> R-help at 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]]

Yes, but colMeans, rowMeans, pmax, pmin , etc. are *much* faster.

Cheers,
Bert


Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Fri, Feb 12, 2016 at 9:15 PM, Jim Lemon <drjimlemon at gmail.com>
wrote:
> Hi Ashta,
> Surely you are aware of the "apply" family of functions that
return the
> numbers you want:
>
> ashmat<-matrix(c(117,12,13,21,21,32,11,1,65,43,23,7,58,61,78,95 ),
>  nrow=4,byrow=TRUE)
> apply(ashmat,2,mean)
> [1] 65.25 37.00 31.25 31.00
> apply(ashmat,1,which.max)
> [1] 1 2 1 4
>
> Jim
>
>
> On Sat, Feb 13, 2016 at 3:04 PM, Ashta <sewashm at gmail.com> wrote:
>
>> hi all,
>>
>> I have  a square matrix (1000 by 1000),
>> 1. I want calculate  mean,  min and max values for each column and row.
>>
>> 2, I want pick the  coordinate value of the matrix that has the max
>> and min value for each row and column.
>> This an example 4 by 4 square matrix
>>
>>
>>                                               Mean    Min    Max
>>             117   12    13     21    40.75       12    117
>>              21    32    11       1     16.25       1       32
>>              65    43    23       7      34.5        7       65
>>              58    61    78     95        73        58      95
>> Mean    65    25    37   31.25
>> Min        21    12    11    1
>> Max     117    61    78    95
>>
>>
>> Thank you
>>
>> ______________________________________________
>> R-help at 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 at 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.