Hi friends,
I m new to R studio and I m facing the problem related to expand.grid. I m trying to create the grid for latitude and longitude. Please see the following codes.
tt<-read.csv(file.choose(),header = TRUE)
#print (tt)
head(tt)
library(marmap)
tt0<-getNOAA.bathy(lon1=63,lon2=78,lat1=7,lat2=25,resolution=4)
tt1<-expand.grid(lon,lat)
Error in expand.grid(lon, lat) : object 'lon' not found
the above line is error showed...
Rest of the codes are below
tt2<-get.depth(tt0,as.matrix(tt1[,1:2]),locator = FALSE)
head(tt0)
head(tt1)
head(tt2)
head(tt3)
tt3<-merge(tt2,tt,by=c("lon","lat"))
tt3$include<-0
tt3[tt3$depth>-200 & tt3$depth<0,]$include<-1
I m trying to extract data for 200m depth from whole file...
Please help me.
Thank you
FJCC
November 7, 2019, 2:12pm
2
The variables lon and lat are not defined anywhere, causing the error. Perhaps you mean
tt1 <- expand.grid(tt0$lon, tt0$lat)
That would produce a result like one of the following where I invented a small example data frame.
DF <- data.frame(lon = c(10, 10, 20), lat = c(5, 10, 10))
GRID <- expand.grid(DF$lon, DF$lat)
GRID
#> Var1 Var2
#> 1 10 5
#> 2 10 5
#> 3 20 5
#> 4 10 10
#> 5 10 10
#> 6 20 10
#> 7 10 10
#> 8 10 10
#> 9 20 10
GRID2 <- expand.grid(unique(DF$lon), unique(DF$lat))
GRID2
#> Var1 Var2
#> 1 10 5
#> 2 20 5
#> 3 10 10
#> 4 20 10
Created on 2019-11-07 by the reprex package (v0.3.0.9000)
1 Like
Dear sir , thanks a lot for help. i have used the codes given by you and it worked successfully. thanks you.
system
Closed
December 5, 2019, 4:18pm
4
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