Message-ID: <71b53a06-7c85-b970-eaf8-b83f0d660ab7@gmail.com>
Date: 2016-05-23T05:39:17Z
From: Steven Yen
Subject: Element-by-element operation (adding)
Hi all, need help below. Thank you.
> # Matrix v is 5 x 3
> # Vector b is of length 3
> # I like to add b[1] to all element in v[,1]
> # I like to add b[2] to all element in v[,2]
> # I like to add b[3] to all element in v[,3]
> # as follows
> v<-matrix(0,nrow=5,ncol=3); v
[,1] [,2] [,3]
[1,] 0 0 0
[2,] 0 0 0
[3,] 0 0 0
[4,] 0 0 0
[5,] 0 0 0
> b<-c(0.1,0.2,0.3)
> cbind(
+ (b[1]+v[,1]),
+ (b[2]+v[,2]),
+ (b[3]+v[,3]))
[,1] [,2] [,3]
[1,] 0.1 0.2 0.3
[2,] 0.1 0.2 0.3
[3,] 0.1 0.2 0.3
[4,] 0.1 0.2 0.3
[5,] 0.1 0.2 0.3
> # I am obviously not using sapply correctly:
> as.data.frame(sapply(b,"+",v))
V1 V2 V3
1 0.1 0.2 0.3
2 0.1 0.2 0.3
3 0.1 0.2 0.3
4 0.1 0.2 0.3
5 0.1 0.2 0.3
6 0.1 0.2 0.3
7 0.1 0.2 0.3
8 0.1 0.2 0.3
9 0.1 0.2 0.3
10 0.1 0.2 0.3
11 0.1 0.2 0.3
12 0.1 0.2 0.3
13 0.1 0.2 0.3
14 0.1 0.2 0.3
15 0.1 0.2 0.3
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