Sum of the multiplication of all columns of one matrix (n-by-m) with another matrix (n-by-n)
I hope the title is self-explanatory. I hoped to make the title such that others could find it as well. I know how to carry out the operation with a loop, but it must be quicker using some kind of matrix multiplication, which I am interested to learn.
The code with the loop looks something like this
x <- matrix(rexp(300, rate=.1), nrow=20)
y <- matrix(rexp(400, rate=.1), nrow=20)
res <- as.data.frame(matrix(0,ncol = 15, nrow = 20))
for (i in 1:20)
res <- res + x*y[,i]
r matrix linear-algebra
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
migrated from stats.stackexchange.com Nov 13 '18 at 16:13
This question came from our site for people interested in statistics, machine learning, data analysis, data mining, and data visualization.
add a comment |
I hope the title is self-explanatory. I hoped to make the title such that others could find it as well. I know how to carry out the operation with a loop, but it must be quicker using some kind of matrix multiplication, which I am interested to learn.
The code with the loop looks something like this
x <- matrix(rexp(300, rate=.1), nrow=20)
y <- matrix(rexp(400, rate=.1), nrow=20)
res <- as.data.frame(matrix(0,ncol = 15, nrow = 20))
for (i in 1:20)
res <- res + x*y[,i]
r matrix linear-algebra
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
migrated from stats.stackexchange.com Nov 13 '18 at 16:13
This question came from our site for people interested in statistics, machine learning, data analysis, data mining, and data visualization.
2
x * rowSums(y)
– Roland
Nov 13 '18 at 13:54
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58
add a comment |
I hope the title is self-explanatory. I hoped to make the title such that others could find it as well. I know how to carry out the operation with a loop, but it must be quicker using some kind of matrix multiplication, which I am interested to learn.
The code with the loop looks something like this
x <- matrix(rexp(300, rate=.1), nrow=20)
y <- matrix(rexp(400, rate=.1), nrow=20)
res <- as.data.frame(matrix(0,ncol = 15, nrow = 20))
for (i in 1:20)
res <- res + x*y[,i]
r matrix linear-algebra
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
I hope the title is self-explanatory. I hoped to make the title such that others could find it as well. I know how to carry out the operation with a loop, but it must be quicker using some kind of matrix multiplication, which I am interested to learn.
The code with the loop looks something like this
x <- matrix(rexp(300, rate=.1), nrow=20)
y <- matrix(rexp(400, rate=.1), nrow=20)
res <- as.data.frame(matrix(0,ncol = 15, nrow = 20))
for (i in 1:20)
res <- res + x*y[,i]
r matrix linear-algebra
r matrix linear-algebra
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
asked Nov 13 '18 at 10:13
pApaAPPApapapapApaAPPApapapa
98210
98210
migrated from stats.stackexchange.com Nov 13 '18 at 16:13
This question came from our site for people interested in statistics, machine learning, data analysis, data mining, and data visualization.
migrated from stats.stackexchange.com Nov 13 '18 at 16:13
This question came from our site for people interested in statistics, machine learning, data analysis, data mining, and data visualization.
2
x * rowSums(y)
– Roland
Nov 13 '18 at 13:54
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58
add a comment |
2
x * rowSums(y)
– Roland
Nov 13 '18 at 13:54
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58
2
2
x * rowSums(y)– Roland
Nov 13 '18 at 13:54
x * rowSums(y)– Roland
Nov 13 '18 at 13:54
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58
add a comment |
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2
x * rowSums(y)– Roland
Nov 13 '18 at 13:54
Just as a side note, when you create reproducible, illustrative examples: a 3x2 matrix and a 3x3 matrix can be a lot simpler to understand and than 20x15 and 20x20 matrices. Often using a really small example helps you find a nice insight.
– Gregor
Nov 13 '18 at 16:23
@Gregor Goodt point. Will keep that in mind for next time!
– pApaAPPApapapa
Nov 14 '18 at 8:54
@Roland This was this simple kind of solution I knew I saw right past. Thanks so much @Roland!
– pApaAPPApapapa
Nov 14 '18 at 8:58