CODEWITHSUNDEEP
r
user8102905
user8102905

Reputation: 191

R function to return matrix rows that satisfy min and max ranges

Having the following matrix:

      [,1] [,2] [,3] [,4] 
  [1,]  231   14  517  310 
  [2,]    1  154   18   21 
  [3,]  121    6  198   23

I want to get only the rows that have a minimum range for each row between 2 and 30.

Min range for each row:

 [1] 79
 [2]  3
 [3] 17

so we get only [2] and [3]

and a max range between 0 and 160 Max range for each row:

  [1] 503
  [2] 153
  [3] 192

so finally we get only [2] that satisfies the two conditions. Can you please provide an R language function which can generate this result?

Regards, Dimitris

Upvotes: 0

Views: 121

Answers (2)

jogo
jogo

Reputation: 12559

Here is a solution using the function dist():

m <- matrix(
  c(231, 14, 517, 310, 
    1,  154,   18,   21, 
  121,    6,  198,   23 ), 3, byrow=TRUE)


mi <- apply(m, 1, function(x) min(dist(x)))
ma <- apply(m, 1, function(x) max(dist(x)))

m[mi > 2 & mi < 30 & ma > 0 & ma < 160, ]

Upvotes: 2

AkselA
AkselA

Reputation: 8846

Setting up the data 

m <- read.table(text="231   14  517  310
                        1  154   18   21
                      121    6  198   23")

m <- as.matrix(m)

Maximum range of each row

maxr <- apply(m, 1, function(x) diff(range(x)))

Minimum range of each row

minr <- apply(m, 1, function(x) min(diff(sort(x))))

Stringing it together into a condition on rows

m[minr > 2 & minr < 20 & maxr > 0 & maxr < 160, ]
#   1 154  18  21

Upvotes: 2

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