I am trying to introduce a custom equation to my ggplot.
data1989 %>%
ggplot(aes(x = daysAFTERFIRE, y = NDVI)) +
stat_function(fun= ~ (.meanNDVI)-(exp(-0.0000348*(.x)-2.17)))
As you see, my custom equation includes both y (column NDVI) and x (column daysAFTERFIRE), but also a third term, meanNDVI which is another column on my tibble.
Trying to run I get this:
Computation failed in `stat_function()`:
object '.meanNDVI' not found
Anyone has any idea to solve this? Thanks!
You could build your function outside of the ggplot call, and then it might be easier to troubleshoot:
Assign your column containing a repeating mean value to a numeric variable:
meanNDVI_variable <- df$meanNDVI[1]
Then use it in your function:
f <- function(.x) (meanNDVI_variable)-(exp(-0.0000348*(.x)-2.17)))
Then:
data1989 %>%
ggplot(aes(x = daysAFTERFIRE, y = NDVI)) +
stat_function(fun= f)))
meanNDVI in a dataframe? Have you tried using df$meanNDVI?f <- function(.x) (data1989$meanNDVI)-(exp(-0.0000348*(.x)-2.17)) as you suggest I get Warning messages: Warning messages: 1: In (data1989$meanNDVI) - (exp(-3.48e-05 * (.x) - 2.17)) : longer object length is not a multiple of shorter object length 2: Computation failed in stat_function(): Elements must equal the number of rows or 1meanNDVI the same number, since it's a calculated mean? If so, you can assign the value to a variable, instead of a value in a dataframe: meanNVDI_variable <- df$meanNDVI[1] and then replace meanNVDI with meanNVDI_variable in your function.