[R-sig-Geo] loop xy cbind

[marta azores]

2016-12-05 12:52 GMT-01:00 marta azores <martazores at gmail.com>:

> Hi everyone,
> I would like to create a loop to split my dataframe with locations by
> transect, , with the objective to get 2 lines, one for each transect .
> I have this script to achieve that... but the results are different that I
> want. I only get the first position (x,y).
>
>  Anyone has an idea to fix that?
> Thanks in advance
>
> Marta
>
>
>
> #script
> #
> ###################################
> #boat <- read.table("C:/mini.csv", header=TRUE, sep=",", na.strings="NA",
> #dec=".",strip.white=TRUE)#
>
> library(plyr)
> library(loop)
>
> boat
>
> #  Idkey IdkeyL     Long1     Lat1  Date      Hour MiniSurvey Sort1 Year
> #1  1968  1968L -28.64475 38.67035 40302 0.7291667      25595     1 2010
> #2  1968  1968L -28.72917 38.66908 40302 0.7437500      25595     2 2010
> #3  1968  1968L -28.74920 38.67173 40302 0.7479167      25595     3 2010
> #4  1969  1969L -28.70907 38.66965 40302 0.7562500      25595     4 2010
> #5  1969  1969L -28.63157 38.64717 40302 0.7715278      25596     5 2010
> #6  1969  1969L -28.87397 38.26693 40303 0.3340278      25597     6 2010
> boat_split <- split(boat, boat$Idkey)
> boat_xy<-(boat_split, cbind(boat$Long1,boat$Lat1))
>
> summary(boat_split)
> #     Length Class      Mode
> #1968 9      data.frame list
> #1969 9      data.frame list
>
> new_names <- c("1968","1969")
> for (i in 1:length(boat_split)) {
>   assign(new_names[i], boat_split[[i]]);
> boat_xy<-cbind(boat$Long1[[i]],boat$Lat1[[i]])}
>
> boat_xy#results
> #     [,1]     [,2]
> #[1,] -28.72917 38.66908
>
> #However, I was expecting a list of dataframes by Idkey
> (c("1968","1969")), with the coordinates, something like that:
> $`1968`
>  -28.72917 38.66908
>  -28.72917 38.66908
>  -28.74920 38.67173
> $`1969`
>  -28.70907 38.66965
>  -28.63157 38.64717
>  -28.87397 38.26693
> class(boat_split)#list
>
> #to get lines : apply this function
> library(sp)
> Sl1 <- Line(boat_xy)
>
>
>

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