[R] How to loop through all the columns in dataframe

[Felipe Carrillo]

--- jim holtman <jholtman at gmail.com> wrote:

> Glad I could help.  You might want to post it back
> to R-Help so that
> others can see what was done.
> 
> On Sun, Mar 16, 2008 at 6:02 PM, Felipe Carrillo
> <mazatlanmexico at yahoo.com> wrote:
> > Jim: I owe you man, this is great,I never thought
> that
> > I could acomplish this task. Now I can estimate
> > confidence intervals for mydf and I will be
> > done,,Thanks again Jim..
> >
> >
> > > This should do what you want: (you had td and pd
> > > reversed in your example)
> > >
> > > > xd <-
> > >
> c(2.2024,2.4216,1.4672,1.4817,1.4957,1.4431,1.5676)
> > > > td <-
> > >
> >
>
c(0.017046,0.018504,0.012157,0.012253,0.012348,0.011997,0.012825)
> > > > pd <-
> > > c(160524,163565,143973,111956,89677,95269,81558)
> > > >  mydf<-data.frame(xd,pd,td)
> > > >  trans<-t(mydf)
> > > >  trans
> > >           [,1]        [,2]        [,3]       
> [,4]
> > >     [,5]
> > > [,6]       [,7]
> > > xd 2.20240e+00 2.42160e+00 1.46720e+00
> 1.48170e+00
> > > 1.4957e+00
> > > 1.4431e+00 1.5676e+00
> > > pd 1.60524e+05 1.63565e+05 1.43973e+05
> 1.11956e+05
> > > 8.9677e+04
> > > 9.5269e+04 8.1558e+04
> > > td 1.70460e-02 1.85040e-02 1.21570e-02
> 1.22530e-02
> > > 1.2348e-02
> > > 1.1997e-02 1.2825e-02
> > > >  varA<- 0.0000036084
> > > >  covAB<- (-0.0000013046)
> > > >  varB<- 0.00000052628
> > > >
> > > > # create the sequences to test against
> > > > i.seq <- lapply(seq(ncol(trans) - 1),
> function(x)
> > > x:(ncol(trans) - 1))
> > > > x <- lapply(i.seq, function(.col){
> > > +     # compute the 3 columns of data
> > > +     cbind(xp=varA + trans[1, .col[1]] * covAB
> +
> > > trans[1, .col + 1] *
> > > covAB + trans[1, .col[1]] * trans[1, .col + 1] *
> > > varB,
> > > +         pd=trans[2, .col[1]] * trans[2, .col +
> 1],
> > > +         td=trans[3, .col[1]] * trans[3, .col +
> 1])
> > > + })
> > > > # rbind for the output
> > > > z <- do.call(rbind, x)
> > > > # add the covariance
> > > > z <- cbind(z, cov=z[, 'xp'] * z[, 'pd'] / z[,
> > > 'td'])
> > > > z
> >
> >
> >
> >  Felipe D. Carrillo
> >  Fishery Biologist
> >  Department of the Interior
> >  US Fish & Wildlife Service
> >  California, USA
> >
> >
> >
> >     
>
____________________________________________________________________________________
> > Be a better friend, newshound, and

>

> >
> >
> 
> 
> 
> -- 
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
> 
> What is the problem you are trying to solve?
> 


 Felipe D. Carrillo
  Fishery Biologist
  Department of the Interior
  US Fish & Wildlife Service
  California, USA