Question

Given a data set with a time stamp and several columns of data following it

data=
           hour          V1           V2          V3
1 2012-01-19 08:00:00  0.04551064  0.002851064  0.01842553
2 2012-01-19 09:00:00 -0.05305000 -0.052266667 -0.07455000
3 2012-01-19 10:00:00 -0.07518333 -0.101333333 -0.10670000
4 2012-01-19 11:00:00 -0.09195000 -0.099383333 -0.11176667
5 2012-01-19 12:00:00 -0.07743333 -0.074000000 -0.09106667
6 2012-01-19 13:00:00 -0.10978333 -0.096200000 -0.11343333

I would like to square the columns V1-V3 giving me this

data_sq=
         hour                V1           V2           V3
1    2012-01-19 08:00:00  0.002071218 8.128565e-06 0.0003395002
2    2012-01-19 09:00:00  0.002814303 2.731804e-03 0.0055577025
3    2012-01-19 10:00:00  0.005652534 1.026844e-02 0.0113848900
4    2012-01-19 11:00:00  0.008454803 9.877047e-03 0.0124917878
5    2012-01-19 12:00:00  0.005995921 5.476000e-03 0.0082931378
6    2012-01-19 13:00:00  0.012052380 9.254440e-03 0.0128671211

As for right now I just use

data_sq<-data^2

to get the square root. But it destroys the time stamp so I have to put it back in with something really awkward like

data_sqd<-cbind(data_sq,data$hour)

I tried

data_sq<-(data[,c(2:4)]^2

but I loose the time stamp as well

So how do I keep my time stamp column intact and specify which columns I want to square? My apologies for the lack of reproducible data, but I am hoping this is a simple enough question I can get away with it 🙂

Answer 1

data_sq <- data # try not to use data, it's a function in base
data_sq[,2:4] <- data[,2:4]^2 # subsetting was off but you were close!