Nothing
## ----pkg-load, echo = FALSE, message = FALSE----------------------------------
library (mapscanner)
library (ggplot2)
requireNamespace ("sf")
# vwidth/height are passed via mapview::mapshot to webshot::webshot,
# and default to (992,744), which bloats package size (issue #27).
red <- 2
vwidth <- 992 / red
vheight <- 744 / red
## ----generate-fakey, eval = FALSE---------------------------------------------
# ms_generate_map ("chennai india", mapname = "chennai")
## ----generate, echo = FALSE---------------------------------------------------
message ("Successfully generated 'chennai.pdf' and 'chennai.png'")
## ----chennaiBrick-fakey, eval = FALSE-----------------------------------------
# x <- ms_generate_map ("chennai india", mapname = "chennai")
## ---- echo = FALSE------------------------------------------------------------
message ("Successfully generated 'chennai.pdf' and 'chennai.png'")
## ----x, eval = FALSE----------------------------------------------------------
# x
## ----chennaiBrick, echo = FALSE-----------------------------------------------
x <- paste0 ("class : RasterBrick\n",
"dimensions : 1147, 562, 644614, 3 (nrow, ncol, ncell, nlayers)\n",
"resolution : 38.21851, 38.21851 (x, y)\n",
"extent : 8921157, 8942635, 1442787, 1486624 (xmin, xmax, ymin, ymax)\n",
"crs : +proj=merc +a=6378137 +b=6378137 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs\n",
"source : memory\n",
"names : index_1.1, index_1.2, index_1.3\n",
"min values : 107, 107, 107\n",
"max values : 254, 254, 254")
message (x)
## ----chennaiBrick2, eval = FALSE----------------------------------------------
# ms_generate_map (raster_brick = x, mapname = "chennai")
## ----omaha-poly-png, echo = FALSE, out.width = "75%", eval = TRUE-------------
op <- system.file ("extdata", "omaha-polygons.png", package = "mapscanner")
f <- file.path (tempdir (), "omama-polygons.png")
chk <- file.copy (op, f)
knitr::include_graphics (f)
## ----rectify, message = FALSE, eval = FALSE-----------------------------------
# f_orig <- system.file ("extdata", "omaha.png", package = "mapscanner")
# f_mod <- system.file ("extdata", "omaha-polygons.png", package = "mapscanner")
# xy <- ms_rectify_map (f_orig, f_mod, nitems = 2)
# xy
## ----rectify-output, echo = FALSE---------------------------------------------
m <- c (
"Simple feature collection with 2 features and 0 fields",
"Geometry type: POLYGON",
"Dimension: XY",
"Bounding box: xmin: -96.11801 ymin: 41.26638 xmax: -96.02722 ymax: 41.30108",
"Geodetic CRS: WGS 84",
" geometry",
"1 POLYGON ((-96.10692 41.2684...",
"2 POLYGON ((-96.0276 41.2964,...")
m <- paste0 (m, collapse = "\n")
message (m)
## ----mapshot-hulls, eval = FALSE, echo = FALSE--------------------------------
# xy$id <- seq (nrow (xy))
# if (!file.exists ("mapshot-polys.png"))
# {
# x <- mapview::mapview (xy)
# mapview::mapshot (x, file = "mapshot-hulls.png",
# remove_controls = c ("layersControl", "zoomControl"),
# vwidth = vwidth, vheight = vheight)
# }
## ----mapview-fakey, eval = FALSE----------------------------------------------
# xy$id <- seq (nrow (xy))
# mapview::mapview (xy)
## ----mapshot-hulls-png, echo = FALSE, out.width = "75%"-----------------------
knitr::include_graphics ("./mapshot-hulls.png")
#plot (xy)
## ----type-polys, eval = FALSE-------------------------------------------------
# f_orig <- system.file ("extdata", "omaha.png", package = "mapscanner")
# f_mod <- system.file ("extdata", "omaha-polygons.png", package = "mapscanner")
# xy <- ms_rectify_map (f_orig, f_mod, type = "polygons", quiet = TRUE)
## ----mapview-polys, eval = FALSE, echo = FALSE--------------------------------
# xy$id <- seq (nrow (xy))
# if (!file.exists ("mapshot-polys.png"))
# {
# x <- mapview::mapview (xy)
# mapview::mapshot (x, file = "mapshot-polys.png",
# remove_controls = c ("layersControl", "zoomControl"),
# vwidth = vwidth, vheight = vheight)
# }
## ----mapview-polys-fakey, eval = FALSE----------------------------------------
# xy$id <- seq (nrow (xy))
# mapview::mapview (xy)
## ----mapshot-polys-png, echo = FALSE, out.width = "75%"-----------------------
knitr::include_graphics ("./mapshot-polys.png")
#plot (xy)
## ----type-points, eval = FALSE------------------------------------------------
# f_orig <- system.file ("extdata", "omaha.png", package = "mapscanner")
# f_mod <- system.file ("extdata", "omaha-polygons.png", package = "mapscanner")
# xy <- ms_rectify_map (f_orig, f_mod, type = "points", quiet = TRUE)
## ----mapview-points, eval = FALSE, echo = FALSE-------------------------------
# xy$id <- seq (nrow (xy))
# if (!file.exists ("mapshot-points.png"))
# {
# x <- mapview::mapview (xy)
# mapview::mapshot (x, file = "mapshot-points.png",
# remove_controls = c ("layersControl", "zoomControl"),
# vwidth = vwidth, vheight = vheight)
# }
## ----mapview-points-fakey, eval = FALSE---------------------------------------
# xy$id <- seq (nrow (xy))
# mapview::mapview (xy)
## ----mapshot-points-png, echo = FALSE, out.width = "75%"----------------------
knitr::include_graphics ("./mapshot-points.png")
#plot (xy)
## ----random-polys-fakey, eval = FALSE-----------------------------------------
# n <- 5 # number of polygons
# polys <- lapply (seq (n), function (i) {
# nxy <- 20 # number of points used to generate hull
# xy <- matrix (runif (2 * nxy), ncol = 2)
# h <- chull (xy)
# sf::st_polygon (list (xy [c (h, h [1]), ]))
# })
# polys <- sf::st_sf (n = seq (n), geometry = polys)
## ----random-polys-fakey2, eval = FALSE----------------------------------------
# aggr <- ms_aggregate_polys (polys)
# polys$type <- "raw polygons"
# aggr$type <- "aggregated polygons"
# polys <- rbind (polys, aggr)
# # Convert type to factor to order facets:
# polys$type <- factor (polys$type, levels = c ("raw polygons", "aggregated polygons"))
# library (ggplot2)
# ggplot (polys, aes (fill = n)) + geom_sf () + facet_wrap (~type)
## ----random-polys, echo = FALSE, eval = TRUE----------------------------------
set.seed (1)
n <- 5 # number of polygons
polys <- lapply (seq (n), function (i) {
nxy <- 20 # number of points used to generate hull
xy <- matrix (runif (2 * nxy), ncol = 2)
h <- chull (xy)
sf::st_polygon (list (xy [c (h, h [1]), ]))
})
polys <- sf::st_sf (n = seq (n), geometry = polys)
aggr <- ms_aggregate_polys (polys)
polys$type <- "raw polygons"
aggr$type <- "aggregated polygons"
polys <- rbind (polys, aggr)
polys$type <- factor (polys$type, levels = c ("raw polygons", "aggregated polygons"))
theme_set (theme_minimal ())
ggplot (polys, aes (fill = n)) + geom_sf () + facet_wrap (~type)
## ----aggr13, eval = TRUE------------------------------------------------------
ggplot (aggr [aggr$n %in% c (1, 3, 5), ], aes (fill = n)) + geom_sf ()
## ----aggr-area, eval = TRUE---------------------------------------------------
aggr$area <- sf::st_area (aggr)
ggplot (aggr, aes (x = n, y = area)) + geom_line (size = 2)
## ----pdfinfo-fakey, eval = FALSE----------------------------------------------
# pdftools::pdf_info ("chennai.pdf")$keys
## ----pdfinfo, echo = FALSE----------------------------------------------------
x <- list ("Title" = "EX8921118.44521949+1442748.9088827+8942673.68719591+1486623.76311839",
"Producer" = "R 4.0.0",
"Creator" = "R")
x
## ----img-comment-fakey, eval = FALSE------------------------------------------
# img <- magick::image_read ("chennai.png")
# magick::image_comment (img)
## ----img-comment, echo = FALSE------------------------------------------------
"EX8921118.44521949+1442748.9088827+8942673.68719591+1486623.76311839"
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