How can I do a Contour plot of a coordinate dataframe in r?

Question

I'm trying to use ggplot to make a contour plot of some weather data. I'm trying to graph the contents of the following dataframe:

dt
          -18.25     -17.75    -17.25    -16.75     -16.25
-67.25 -1.042116 -0.2610118  3.527539  1.698116  5.8457116
-66.75 10.888635 10.7380880  5.282561 10.558529 12.0000000
-66.25 11.793157 -0.1322045 12.000000 12.000000 12.0000000
-65.75  9.407542 11.4077278 12.000000 12.000000 -0.6859424
-65.25  6.355656  9.4592526 12.000000 -2.770040 -4.0922426
-64.75  3.103860 12.0000000  3.928329 -5.728103 -5.2666501
-64.25  6.720593 10.5359569 -2.267352 -7.223494 -6.5408307

Here, column names are the latitude and the rownames are the longitude.

> lon
[1] -67.75 -67.25 -66.75 -66.25 -65.75 -65.25 -64.75 -64.25 -63.75
> lat
[1] -18.75 -18.25 -17.75 -17.25 -16.75 -16.25 -15.75

And the values in the dataframe are the ones I want to contour in eaxh coordinate.

In order to graph this, I'm using the following function:

ggplot(dt) +  
  geom_density_2d_filled(aes(x=rownames(dt),y=names(dt)))

But whenever I try to do yhis, I get the following error:

Error in check_aesthetics(): ! Aesthetics must be either length 1 or the same as the data (7): y

I would really appreciate any insights to solve this problem!

user_13321647 · Answer

You have vectors with different length. Therefore bring them to the same length and plot:

Update with the original data:

library(tidyverse)

lon <- c(-67.75, -67.25, -66.75,  -66.25,  -65.75,  -65.25,  -64.7, 5 -64.25,  -63.75)
lat <- c(-18.75, -18.25,  -17.75,  -17.25,  -16.75,  -16.25,  -15.75)
x <- lon
y <- lat
max.len = max(length(x), length(y))
x = c(x, rep(NA, max.len - length(x)))
y = c(y, rep(NA, max.len - length(y)))

tibble(x,y) %>% 
  ggplot(aes(x, y)) +
  geom_density_2d()

First answer:

library(tidyverse)

x <- colnames(dt)
y <- rownames(dt)


max.len = max(length(x), length(y))
x = c(x, rep(NA, max.len - length(x)))
y = c(y, rep(NA, max.len - length(y)))

tibble(x,y) %>% 
  mutate(x = parse_number(x)) %>% 
  mutate(y = as.numeric(y)) %>% 
  ggplot(aes(x, y)) +
  geom_density_2d()

data:

x <- c("18.25", "17.75", "17.25", "16.75", "16.25")
y <- c("-67.25", "-66.75", "-66.25", "-65.75", "-65.25", "-64.75", "-64.25")

How can I do a Contour plot of a coordinate dataframe in r?

1 Answers