[R] remove rows of a matrix by part of its row name

[Rui Barradas]

Hello,

Use grep to get the row indices and then subset with a *negative* index 
to remove those rows.

rn <- scan(what = character(), text = "
70/556
71.1/280
72.1/556
72.1/343
73.1/390
73.1/556
")

mat <- matrix(rnorm(6*6), nrow = 6)
row.names(mat) <- rn

inx <- grep("73\\.", row.names(mat))

new_mat <- mat[-inx, ]
new_mat


Hope this helps,

Rui Barradas

On 5/22/2018 11:48 AM, Ahmed Serag wrote:
> Dear R-experts,
> 
> 
> How can I remove a certain feature or observation by a part of its name. To be clear, I have a matrix with 766 observations as a rows. The row names are like this
> 
> 70/556
> 71.1/280
> 72.1/556
> 72.1/343
> 73.1/390
> 73.1/556
> Now I would like to remove all the rows that contain the text 73.1
> 
> Any ideas or suggestion please ?
> 
> 
> Regards
> 
> 
> 
> 
> **********************
> 
> Ahmed Serag
> 
> Analytical Chemistry Department
> 
> Faculty of Pharmacy
> 
> Al-Azhar University
> 
> Cairo
> 
> Egypt
> 
> 	[[alternative HTML version deleted]]
> 
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