tests/testthat/test_polySplit.R

In jmt2080ad/polylineSplitter: Split lines into segments

context("polySplit")

library(magrittr)
library(sp)
library(parallel)

test_that("splitLines works", {
    ## basic line splitting
    x <- c(0.549, 0.707, 1.044, 1.652, 2.530, 2.890, 3.520, 4.218, 4.781, 4.848, 
           4.893, 4.893, 4.848, 5.006, 5.951, 6.289, 7.077, 7.909, 8.967)  
    y <- c(0.667, 1.474, 2.778, 3.063, 4.131, 4.582, 5.341, 5.412, 5.460, 5.554, 
           5.673, 5.863, 6.029, 6.100, 6.622, 7.168, 7.476, 7.453, 7.500)
    
    ldat <- Line(data.frame(x,y)) %>%
        list() %>%
        Lines(ID = 1) %>%
        list() %>%
        SpatialLines()
    
    ldatSplit <- suppressWarnings(splitLines(ldat, 3))
    
    expect_equal(length(ldatSplit), 5)
    
    expect_equal(ldatSplit@lines[[2]]@Lines[[2]]@coords[1,], setNames(c(x[5], y[5]), c("x", "y")))
    
    sf_ldat <- sf::st_linestring(matrix(c(x,y), ncol = 2))
    
    sf_ldatSplit <- splitLines(sf_ldat, 3, sf = T)
    
    expect_equal(class(sf_ldatSplit), c("sf", "data.frame"))
    
    expect_equal(sf::st_coordinates(sf_ldatSplit)[7,c(1:2)], setNames(c(x[5], y[5]), c("X", "Y")))
    
    ## plot(sf_ldatSplit)
    ## png("../../images/line_splitting.png", width = 960)
    ## par(mfrow = c(1,2))
    ## plot(ldat, col = rainbow(length(ldat)), main = "Original Line", lwd = 2)
    ## plot(ldatSplit, col = rainbow(nrow(ldatSplit)), main = "Split Line", lwd = 2)
    ## dev.off()
})

test_that("splitPoints works", {
    ## polygon applications
    x <- c(1.518, 1.908, 3.452, 5.562, 6.968, 7.965, 8.043, 6.949, 5.542, 4.800, 4.644, 
           4.409, 4.116, 3.823, 3.471, 3.217, 3.022, 2.495, 2.026, 1.889, 1.518, 1.479, 1.420)
    y <- c(4.594, 6.295, 7.233, 7.800, 6.338, 5.226, 3.721, 2.020, 2.042, 2.478, 2.980, 
           3.481, 3.743, 3.808, 3.896, 3.939, 3.896, 3.743, 3.678, 3.787, 3.918, 4.157, 4.288)
    
    pdat <- Polygon(data.frame(x,y)) %>%
        list() %>%
        Polygons(ID = 1) %>%
        list() %>%
        SpatialPolygons()
    
    ## sample intervals
    pdatSplit <- splitPoints(as(pdat, "SpatialLines"), 1)
    
    expect_equal(length(pdatSplit), 21)
    
    expect_equal(round(sum(pdatSplit@coords), 3), 200.104)
    
    ## png("../../images/polygon_sampling.png", width = 960)
    ## par(mfrow = c(1,2))
    ## plot(pdat, col = rainbow(length(pdat)), main = "Original Polygon", lwd = 2)
    ## plot(pdatSplit, col = rainbow(length(pdatSplit)), main = "Sampled Along Polygon Edge\nAt Even Intevals", lwd = 2)
    ## dev.off()
    
    ## ## polygon simplification
    ## pdatSplit <- splitPoints(as(pdat, "SpatialLines"), 1)
    ## 
    ## pdatSimp <- Polygon(pdatSplit@coords) %>%
    ##   list() %>%
    ##   Polygons(ID = 1) %>%
    ##   list() %>%
    ##   SpatialPolygons()
    ## 
    ## png("../../images/polygon_simplification.png", width = 960)
    ## par(mfrow = c(1,2))
    ## plot(pdat, col = rainbow(length(pdat)), main = "Original Polygon", lwd = 2)
    ## plot(pdatSimp, col = rainbow(length(pdatSimp)), main = "Simplified Polygon via Line Splitting", lwd = 2)
    ## dev.off()
    
}) 

test_that("splitLines works", {

    x <- c(1.518, 1.908, 3.452, 5.562, 6.968, 7.965, 8.043, 6.949, 5.542, 4.800, 4.644, 
           4.409, 4.116, 3.823, 3.471, 3.217, 3.022, 2.495, 2.026, 1.889, 1.518, 1.479, 1.420)
    y <- c(4.594, 6.295, 7.233, 7.800, 6.338, 5.226, 3.721, 2.020, 2.042, 2.478, 2.980, 
           3.481, 3.743, 3.808, 3.896, 3.939, 3.896, 3.743, 3.678, 3.787, 3.918, 4.157, 4.288)
    
    pdat <- Polygon(data.frame(x,y)) %>%
        list() %>%
        Polygons(ID = 1) %>%
        list() %>%
        SpatialPolygons()
    
    ## sample intervals
    pdatSplit <- splitPoints(as(pdat, "SpatialLines"), 1)
    
    expect_equal(length(pdatSplit), 21)
    
    expect_equal(round(sum(pdatSplit@coords), 3), 200.104)
    
    ## png("../../images/polygon_sampling.png", width = 960)
    ## par(mfrow = c(1,2))
    ## plot(pdat, col = rainbow(length(pdat)), main = "Original Polygon", lwd = 2)
    ## plot(pdatSplit, col = rainbow(length(pdatSplit)), main = "Sampled Along Polygon Edge\nAt Even Intevals", lwd = 2)
    ## dev.off()
    
    ## ## polygon simplification
    ## pdatSplit <- splitPoints(as(pdat, "SpatialLines"), 1)
    ## 
    ## pdatSimp <- Polygon(pdatSplit@coords) %>%
    ##   list() %>%
    ##   Polygons(ID = 1) %>%
    ##   list() %>%
    ##   SpatialPolygons()
    ## 
    ## png("../../images/polygon_simplification.png", width = 960)
    ## par(mfrow = c(1,2))
    ## plot(pdat, col = rainbow(length(pdat)), main = "Original Polygon", lwd = 2)
    ## plot(pdatSimp, col = rainbow(length(pdatSimp)), main = "Simplified Polygon via Line Splitting", lwd = 2)
    ## dev.off()
    
}) 

test_that("splitLines works", {

    cl <- makeCluster(detectCores())

    clusterEvalQ(cl, {
        library(rgdal)
        library(polylineSplitter)
        riv <- readOGR("./data/riv_test/", "riv")
    })

    tests <- parLapply(cl, 1:200, function(x){
        tryCatch(splitLines(spobj = riv, dist = x),
                 error = function(e) return(as.character(x)))})

    stopCluster(cl)

    expect_equal(length(which(sapply(tests, function(x) class(x) == "character"))), 0)

})