All Questions
177 questions
1
vote
2
answers
113
views
How to create a mask based on points coordinates?
Starting from this situation:
I would like to create a boolean mask where all external points are considered as True while all internal point are False. Something like this :
The objective would be ...
- 159
1
vote
3
answers
120
views
Can we retrieve entries from a tibble using index matrix?
I have a matrix where the row and column indices are stored that I want to retrieve from a dataset. With a data.frame this works fine:
set.seed(1)
df <- data.frame(a= letters[1:10], b= LETTERS[1:10]...
- 1,324
2
votes
1
answer
102
views
Minimum required number of rows in a boolean matrix, such that the resulting submatrix has at least one `1` in each column?
Background
Let's say, in a boolean matrix m, we have 1s randomly distributed in each row, e.g.,
> set.seed(1)
> (m <- matrix(+(runif(30) > 0.6), 6))
[,1] [,2] [,3] [,4] [,5]
[1,] ...
- 104k
0
votes
2
answers
92
views
Subsetting a matrix returns a vector not a matrix
Using the below code, I am trying to subset the id matrix which has a dim of 100,000*27. The code below keeps rows that have values of 1,3 and 5. The subsetting is successful but what I got (id13) is ...
- 556
0
votes
1
answer
35
views
How to add a value across rows for a column sample based on a condition
I have two dataset and I want to do this:
dput(gt_df)
structure(list(rs1 = c(1, 1), rs2 = c(0, 0), rs8 = c(1, 1), rs21 = c(0,
0)), row.names = c("1117F", "1XZ7S"), class = "...
- 75
0
votes
1
answer
38
views
How to subset a generated list as it works its way through iterations of tidyverse imap function?
In the below simplified example code, using the tidyverse imap() function I'm trying to get the "Inflow" columns of the matrixes generated after the first matrix of the same sublist group to ...
1
vote
2
answers
47
views
subset a matrix by a expression with a column name
data<- matrix(c(1,2,3,4,5,6,7,8,9), nrow=3)
colnames(data) <- c("a", "b", "c")
How can we achieve the following for a matrix when the columnname (b) must be in the ...
- 39
0
votes
1
answer
88
views
Subset a dataframe to include samples from another file
I currently have a count matrix data.frame where the rownames are the genes and the colnames are the sample names
head(colnames(countmatrix_clean_cl_mouse))
[1] "UB01.31YE" "UT38.78EE&...
- 123
10
votes
8
answers
634
views
Select matrix rows that are permutations of a given vector
I have a matrix X:
one two three four
[1,] 1 3 2 4
[2,] 2 0 1 5
[3,] 3 2 1 4
[4,] 4 9 11 19
[5,] 4 3 2 1
I want to get a new matrix Y which only contains ...
- 103
3
votes
1
answer
132
views
Removing columns from a "big.matrix" gives error: "cannot allocate vector of size 37.6 Gb" [duplicate]
I have a large "big.matrix" and I need to remove a few columns from it. It was created from a CSV file (with 72 million rows) using
BigMat <- read.big.matrix("matrix.csv", type=&...
- 101
0
votes
2
answers
82
views
How to use R's loop to get the part of the aggregate matrix other than the many subset matrices?
I have two matrices of pure numbers, and their format is the same: the first column is the group name, the second is the starting number, and the third is the ending number. Each group is the name of ...
- 15
0
votes
1
answer
32
views
Replacing elemnts of an R matrix using a location matrix in R
In the following example i am trying to replace some elements of a two columns matrix m using a two column matrix containing row and columns positions.
bbb
[,1] [,2]
[1,] 21 1
[2,] 15 ...
- 1
3
votes
2
answers
406
views
Choose odd rows and columns from an original matrix [duplicate]
I'm trying to get the elements from odd rows and columns of a matrix. With the matrix being:
a = rbind(c(NA,2,-1,-2), c(0,1,3,0), c(0,NA,0,-1),c(3,1,5,NA))
I'm trying to get:
[,1] [,2]
[1,] NA ...
user17153595
0
votes
1
answer
33
views
How to match two column values in df1 and extract corresponding values in R
Table 1:
Pos
Samples
129
ERR5678
460
ERR7890
568
ERR7689
Table 2:
Pos
ERR5678
ERR7890
ERR7689
129
67890
76879
67894
460
56782
123478
678390
568
78926
890765
345678
Result Table
Pos
Samples
Dp_value
...
-1
votes
1
answer
128
views
Selecting a subset of columns in a matrix using values stored in another matrix in Python
I am trying to subset a matrix by using values from another smaller matrix. The number of rows in each are the same, but the smaller matrix has fewer columns. Each column in the smaller matrix ...
- 73