Remove elements when getting the "missing element" error - r

Question

I have a data set df that I subset into two list int1 and int2. Each one of the elements in this list represents a 10-day period for single individual (e.g., the first three elements in int1 represent three different 10-day periods for ID "A"). int2 is a bit different because it only has one 10-day period for ID "A" and "B". This is because the data for month 4 only has one 10-day period.
I also have a list l1 that contains two matrices.
Setting up the example data:
library(lubridate)
library(tidyverse)
library(purrr)
date <- rep_len(seq(dmy("01-01-2011"), dmy("10-04-2011"), by = "days"), 100)
ID <- rep(c("A","B"), 100)
df <- data.frame(date = date,
x = runif(length(date), min = 60000, max = 80000),
y = runif(length(date), min = 800000, max = 900000),
ID)
df$julian <- yday(df$date)
df$month <- month(df$date)
int1 <- df %>%
mutate(new = floor_date(date, '10 day')) %>%
mutate(new = if_else(day(new) == 31, new - days(10), new)) %>%
group_by(ID, new) %>%
filter(month == "1") %>%
group_split()
int2 <- df %>%
mutate(new = floor_date(date, '10 day')) %>%
mutate(new = if_else(day(new) == 31, new - days(10), new)) %>%
group_by(ID, new) %>%
filter(month == "4") %>%
group_split()
m1 <- matrix(1:9, nrow = 3, ncol = 3)
m2 <- matrix(20:28, nrow = 3, ncol = 3)
l1 <- list(m1, m2)
In the following code, I use the objects that I have created above. g1 is created as a sequence that is used in lstMat.
f1 is a function that does a number of calculations between int1 and int2 is also created to be used in lstMat.
g1 <- rep(seq_along(l1), sapply(l1, nrow))
# Function to calculate the number of julian dates between the first date in the
# first interval and the first date of the second interval
f1 <- function(.int1, .int2) {
t(outer(seq_along(.int1), seq_along(.int2),
FUN = Vectorize(function(i, j) {
min(.int1[[i]]$jDate) -
min(.int2[[j]]$jDate)
})
))
}
g1 <- rep(seq_along(l1), sapply(l1, nrow))
# Function to calculate the number of julian dates between the first date in the
# first interval and the first date of the second interval
f1 <- function(.int1, .int2) {
t(outer(seq_along(.int1), seq_along(.int2),
FUN = Vectorize(function(i, j) {
min(.int1[[i]]$jDate) -
min(.int2[[j]]$jDate)
})
))
}
This is the section of my script that I have been getting an error on.
lstMat <- purrr::map2(split(int1[seq_len(length(g1))], g1),
split(int2[seq_len(length(g1))], g1), f1)
Here is the error:
Error in `stop_subscript()`:
! Can't subset elements that don't exist.
x Locations 3, 4, 5, and 6 don't exist.
i There are only 2 elements.
Run `rlang::last_error()` to see where the error occurred.
I think the error is occuring due to the mismatch in length between g1 and int2 when trying to create the lstMat object. I was wondering how I could modify the code to remove those missing elements from g1 when I try to split int2 based on the g1 when running lstMat.