rasciirastercoordinate

Converting coordinate ASC file (raster data) into a XY coordinate data frame


I have read in an ASCII file with values that correspond to a UK coordinate grid, however, if I want to apply the which.closest() command I need to be able to specify the columns in terms of X and Y coordinates. So right now, below is an random example extract of the type of data frame I have:

           1000 2000 3000 4000 5000
    66000     1    2    3    4    5
    65000     1    2    3    4    5
    64000     1    2    3    4    5
    63000     1    2    3    4    5
    62000     1    2    3    4    5

Here is the script so you can reproduce this extract:

    a=c(1,1,1,1,1)
    b=c(2,2,2,2,2)
    c=c(3,3,3,3,3)
    d=c(4,4,4,4,4)
    e=c(5,5,5,5,5)
    df=data.frame(a,b,c,d,e)
    colnames_df=seq(1000,5000,1000)
    rownames_df=seq(62000,66000,1000)
    rownames_df=rev(rownames_df)
    colnames(df)=colnames_df
    rownames(df)=rownames_df
    df

and this is the data frame I want to be able to continue my analysis:

    X     Y      Z
    1000  62000  1
    1000  63000  1
    3000  64000  1
    1000  65000  1
    1000  66000  1
    2000  62000  2
    2000  63000  2
    2000  64000  2
    2000  65000  2
    2000  66000  2 
    ...(etc.)

Is there a code that can do this easily rather than manually setting up a new data frame, specifying columns and rows, etc. because I have a data frame 1377 x 812 for 20 different air quality chemical measurements, so if there is a code it would make my life a lot easier. Any help is appreciated! Thank you!


Solution

  • If I understood correctly what you need :

    library(dplyr)
    library(tidyr)
    df <- cbind(Y = rownames(df), df)
    rownames(df) <- NULL
    df <- df %>% gather(X, Z, -Y)