R help - Mar 2015 - Comparing each component of vector to each component of a Matrix.

Hi All,

I need a help on a loop which can compare the each component of vector to
each component of a Matrix.

Let a vector b = {b1, b2, ...,bn} and 2x2  matrix A = Aij.

I need to compare each component of the vector with each component of a
matrix and print 1 if the component is less or equal to one and print 0
otherwise.

bi <= Aij, print 1 and 0 otherwise.

Any help is appreciated.

Regards,
Frederic.


Frederic Ntirenganya
Maseno University,
African Maths Initiative,
Kenya.
Mobile:(+254)718492836
Email: fredo at aims.ac.za
https://sites.google.com/a/aims.ac.za/fredo/

	[[alternative HTML version deleted]]

Hi,

you didn't specify values in A, and you first wanted to compare bi
with Aij, but then also which bi is less/equal to zero.

For the first case, with

A <- matrix(0:3,2)
b <- seq(-1,5)

and a comparison function for bi less/equal to Aij like

f <- function (bi) {as.integer(bi<=A)}

you can iterate along b with

lapply(b, f) # contains results as matrices in a list, each with same
dimensions as A
sapply(b, f) # aligns results to an length(A)*length(b) matrix


Best,
S.



On 11 March 2015 at 08:01, Frederic Ntirenganya <ntfredo at gmail.com>
wrote:
> Hi All,
>
> I need a help on a loop which can compare the each component of vector to
> each component of a Matrix.
>
> Let a vector b = {b1, b2, ...,bn} and 2x2  matrix A = Aij.
>
> I need to compare each component of the vector with each component of a
> matrix and print 1 if the component is less or equal to one and print 0
> otherwise.
>
> bi <= Aij, print 1 and 0 otherwise.
>
> Any help is appreciated.
>
> Regards,
> Frederic.
>
>
> Frederic Ntirenganya
> Maseno University,
> African Maths Initiative,
> Kenya.
> Mobile:(+254)718492836
> Email: fredo at aims.ac.za
> https://sites.google.com/a/aims.ac.za/fredo/
>
>         [[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.

On 11/03/15 20:01, Frederic Ntirenganya wrote:
> Hi All,
>
> I need a help on a loop which can compare the each component of vector to
> each component of a Matrix.
>
> Let a vector b = {b1, b2, ...,bn} and 2x2  matrix A = Aij.
>
> I need to compare each component of the vector with each component of a
> matrix and print 1 if the component is less or equal to one and print 0
> otherwise.
>
> bi <= Aij, print 1 and 0 otherwise.
>
> Any help is appreciated.
outer(b,A,"<=")+0

cheers,

Rolf Turner

-- 
Rolf Turner
Technical Editor ANZJS
Department of Statistics
University of Auckland
Phone: +64-9-373-7599 ext. 88276
Home phone: +64-9-480-4619