Might be clearer if some variables are created first:: values <- data[, 1] ok <- data[, 2] == 1 sum( (values[ok] - 7)^2 )
On the other hand if you prefer obsfucation replace the last line with: deviance(lm(values-7 ~ 0, subset = ok)) On Thu, Jul 21, 2016 at 11:27 AM, Tim Appelhans <[email protected]> wrote: > Steve, > > sum((data[ ,1][data[, 2] == 1] - a)^2) > > Hope that helps, > Tim > > > On 21.07.2016 17:20, Steven Stoline wrote: >> >> Dear All: good morning >> >> I do need your help how to do the following calculation: >> >> Assume we have a matrix 13x2 (say). Two columns named dataval and index >> >> dataval index >> 20 1 >> 11 0 >> 34 0 >> 54 1 >> 76 1 >> 76 0 >> 61 1 >> 88 1 >> 91 0 >> 11 0 >> 23 1 >> 45 1 >> 53 0 >> >> >> data<-matrix(c(20,11,34,54,76,76,61,88,91,11,23,45,53,1,0,0,1,1,0,1,1,0,0,1,1,0),13,2) >> >> data >> >> I need to perform the calculation: >> >> for a = 7 (say) >> >> sum((data[ ,1] - a)^2) >> >> only for index = data[ ,2] = 1 >> >> >> I am expecting the result to be equal to: >> >> (20-7)^2 + (54-7)^2+(76-7)^2+(61-7)^2+(88-7)^2+(23-7)^2+(45-7)^2 = 18316 >> >> >> Any helps will be highly appreciated. >> >> >> with many thanks >> steve >> ------------------------- >> Steven M. Stoline >> 1123 Forest Avenue >> Portland, ME 04112 >> [email protected] >> >> [[alternative HTML version deleted]] >> >> _______________________________________________ >> [email protected] mailing list >> https://stat.ethz.ch/mailman/listinfo/r-sig-teaching > > > -- > ##################################### > Tim Appelhans > Department of Geography > Environmental Informatics > Philipps Universität Marburg > Deutschhausstraße 12 > Raum 00A08 > 35032 Marburg (Paketpost: 35037 Marburg) > Germany > > Tel +49 (0) 6421 28-25957 > > http://environmentalinformatics-marburg.de/ > > > _______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-sig-teaching -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com _______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-teaching
