On 28-Nov-04 ebashi wrote: > I'll appreciate if some one can help me with the > following loop. This is the logic of the loop, > if we have the following data; >> x.df > x.dif > . . > . . > 102 0.00 > 103 0.42 > 104 0.08 > 105 0.00 > 106 0.00 > 107 0.00 > 108 -0.16 > 109 -0.34 > 110 0.00 > 111 -0.17 > 112 -0.33 > 113 0.00 > 114 0.00 > 115 0.00 > 116 0.33 > 117 0.17 > 118 0.00 > . . > . . > I'm trying to find i's where > for (i in 2:length(x.dif)) > if (x.dif[i-1]<=0 and x.dif[i]>0 and x.dif[i+2]>0) > it would return i+2 to me, > How can I turn this to a right format as a loop.(I > can't figure out the syntax)
In this sort of case you can do it without a loop. The following code (which as written is specific to the precise question you have asked) is the sort of thing you can use: n<-length(x.dif) y2<-x.dif[4:n] y0<-x.dif[2:(n-2)] y1<-x.dif[1:(n-3)] which((y1<=0)&(y0>0)&(y2>0))+3 Hoping this helps, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 [NB: New number!] Date: 28-Nov-04 Time: 12:10:00 ------------------------------ XFMail ------------------------------ ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
