library(oce)

test_that("curl 1", {
    lat <- c(85, 82.5, 80, 77.5)
    lon <- c(160, 162.5, 165, 167.5)
    taux <- matrix(c(1, 6, 9, 3, 7, 11, 14, 10, 4, 13, 2, 12, 16, 8, 15, 5), nrow = 4, ncol = 4, byrow = TRUE)
    tauy <- matrix(c(3, 20, 1, 14, 1, 19, 2, 6, 21, 13, 28, 16, 24, 4, 15, 17), nrow = 4, ncol = 4, byrow = TRUE)
    C <- curl(u = taux, v = tauy, x = lon, y = lat, geographical = TRUE, method = 2)
    expect_equal(C$curl[1, 1], -0.000033388485)
    expect_equal(C$x[1], 161.25)
    expect_equal(C$y[1], 83.75)
})

test_that("curl 2", {
    x <- 1:4
    y <- 1:10
    u <- outer(x, y, function(x, y) y / 2)
    v <- outer(x, y, function(x, y) -x / 2)
    C1 <- curl(u = u, v = v, x = x, y = y, geographical = FALSE, method = 1)
    expect_equal(C1$curl, matrix(-1, nrow = 4, ncol = 10))
    C2 <- curl(u = u, v = v, x = x, y = y, geographical = FALSE, method = 2)
    expect_equal(C2$curl, matrix(-1, nrow = 3, ncol = 9))
})