I have 10 lat and long points. With the code below, I can plot the coordinates, draw arrows in the order of their sequence and out-put a gif file that shows navigation order.
So far I was able to do this only with plot {graphics} function. because arrow {graphics} and saveGIF{animation} only seems to work with the plot function. I am wondering if its possible to this a more appropriate library such as ggmap (edit: I had mistakenly said ggplot), googleVis and etc.
library(graphics)
library(animation)
lat <- c(34.083398,34.072467,34.030237,34.597334,34.587142,34.488386,33.443484,33.946902,33.062739,32.273711,32.272611)
lon <- c(-107.907107,-106.893156,-107.971542,-105.225107,-105.13397,-103.196355,-104.52479,-103.655698,-106.0156,-107.71744,-107.713977)
coords = data.frame(lat,lon)
x <- coords$lat ; y <- coords$lon
s <- seq(length(x)-1) # one shorter than data
saveGIF({
for(s in 1:length(x)){
plot(x,y)
arrows(x[s], y[s], x[s+1], y[s+1], col = 1:s)
}
})
Yes, just remember to wrap your ggplot calls in print so they produce output. Toy example:
data=data.frame(i=1:100,x=runif(100),y=runif(100))
saveGIF({for(i in 2:100){print(ggplot(data[1:i,],aes(x=x,y=y))+geom_point())}})
Just write your code to produce each frame with ggplot2 functions and wrap in print. What did you try?
Related
I want to overlay two raster objects.
I asked the question(Raster overlay visualization in rasterVis package: How the Significant raster images are represented as point marks?).
I refer to the #thiagoveloso'answer from this(Adding stippling to image/contour plot).
But the display is not what I wanted. It's not obvious and beautiful. If I try to change the shape or size of the mark, it will take a long long long time to draw or become weird.
Here is my code:
library(raster)
library(rasterVis)
rm(list = ls())
MK<-raster("C:/e_Zs——trend.tif")
### MK<1.96 set value to NA
fun <- function(x) { x[x<3] <- NA; return(x) }
MK<-calc(MK,fun = fun)
## load trend
Trend<- raster("C:/e_slope_trend.tif")
# And this is the key step:
# Converting the "mask" raster to spatial points
r.mask <- rasterToPoints(MK, spatial=TRUE)
plot(r.mask,cex=0.01)
# Plot
levelplot(Trend, margin=NA,par.settings=RdBuTheme) +
latticeExtra::layer(sp.points(r.mask, pch=100, cex=0.1, alpha=0.3,col="Black"))
I want to draw a fig,like:
And the fig like:
If i change the cex=0.5,it will lke:
If I change the shape of the mark, it will do so long... So. get any idea?
In short: I'm looking for a way to get the exact coordinates of a series of mouse positions (on-clicks) in an interactive x/y scatter plot rendered by ggplot2 and ggplotly.
I'm aware that plotly (and several other interactive plotting packages for R) can be combined with Shiny, where a box- or lazzo select can return a list of all data points within the selected subspace. This list will be HUGE in most of the datasets I'm analysing, however, and I need to be able to do the analysis reproducibly in an R markdown format (writing a few, mostly less than 5-6, point coordinates is much more readable). Furthermore, I have to know the exact positions of the clicks to be able to extract points within the same polygon of points in a different dataset, so a list of points within the selection in one dataset is not useful.
The grid.locator() function from the grid package does almost what I'm looking for (the one wrapped in fx gglocator), however I hope there is a way to do the same within an interactive plot rendered by plotly (or maybe something else that I don't know of?) as the data sets are often HUGE (see the plot below) and thus being able to zoom in and out interactively is very much appreciated during several iterations of analysis.
Normally I have to rescale the axes several times to simulate zooming in and out which is exhausting when doing it MANY times. As you can see in the plot above, there is a LOT of information in the plots to explore (the plot is about 300MB in memory).
Below is a small reprex of how I'm currently doing it using grid.locator on a static plot:
library(ggplot2)
library(grid)
p <- ggplot(mtcars, aes(wt, mpg)) +
geom_point()
locator <- function(p) {
# Build ggplot object
ggobj <- ggplot_build(p)
# Extract coordinates
xr <- ggobj$layout$panel_ranges[[1]]$x.range
yr <- ggobj$layout$panel_ranges[[1]]$y.range
# Variable for selected points
selection <- data.frame(x = as.numeric(), y = as.numeric())
colnames(selection) <- c(ggobj$plot$mapping$x, ggobj$plot$mapping$y)
# Detect and move to plot area viewport
suppressWarnings(print(ggobj$plot))
panels <- unlist(current.vpTree()) %>%
grep("panel", ., fixed = TRUE, value = TRUE)
p_n <- length(panels)
seekViewport(panels, recording=TRUE)
pushViewport(viewport(width=1, height=1))
# Select point, plot, store and repeat
for (i in 1:10){
tmp <- grid.locator('native')
if (is.null(tmp)) break
grid.points(tmp$x,tmp$y, pch = 16, gp=gpar(cex=0.5, col="darkred"))
selection[i, ] <- as.numeric(tmp)
}
grid.polygon(x= unit(selection[,1], "native"), y= unit(selection[,2], "native"), gp=gpar(fill=NA))
#return a data frame with the coordinates of the selection
return(selection)
}
locator(p)
and from here use the point.in.polygon function to subset the data based on the selection.
A possible solution could be to add, say 100x100, invisible points to the plot and then use the plotly_click feature of event_data() in a Shiny app, but this is not at all ideal.
Thanks in advance for your ideas or solutions, I hope my question was clear enough.
-- Kasper
I used ggplot2. Besides the materials at https://shiny.rstudio.com/articles/plot-interaction.html, I'd like to mention the following:
Firstly, when you create the plot, don't use "print( )" within "renderPlot( )", or the coordinates would be wrong. For instance, if you have the following in UI:
plotOutput("myplot", click = "myclick")
The following in the Server would work:
output$myplot <- renderPlot({
p = ggplot(data = mtcars, aes(x=mpg, y=hp)) + geom_point()
p
})
But the clicking coordinates would be wrong if you do:
output$myplot <- renderPlot({
p = ggplot(data = mtcars, aes(x=mpg, y=hp)) + geom_point()
print(p)
})
Then, you could store the coordinates by adding to the Server:
mydata = reactiveValues(x_values = c(), y_values = c())
observeEvent(input$myclick, {
mydata$x_values = c(mydata$x_values, input$myclick$x)
mydata$y_values = c(mydata$y_values, input$myclick$y)
})
In addition to X-Y coordinates, when you use facet with ggplot2, you refer to the clicked facet panel by
input$myclick$panelvar1
I want to plot SpatialPolygonsDataFrame as a semi-transparent main object (with legend on the right), but I want to plot yet additional raster (hillshade) as a background - just to make nicer map. I would need something like:
spplot(polygons, sp.layout = list(list("raster", myRaster)))
but looking at ?spplot, it doesn't seem to be possible to specify the raster in sp.layout. I can't specify the raster as the main object, because the main object are the polygons dataFrame, whose value scale I want to plot in the legend on the right side.
How is it possible to plot an additional raster in spplot?
Here's one way to do it. There's probably a neater way to achieve it without plotting the polygon object twice, though...
library(sp)
library(rasterVis)
r <- raster(nrow=18, ncol=36)
r[] <- runif(ncell(r)) * 10
r[r > 8] <- NA
pol <- rasterToPolygons(r, function(x) x > 6)
spplot(pol) + levelplot(r) + spplot(pol)
Or alternatively:
library(latticeExtra)
spplot(pol) + spplot(r) + spplot(pol)
EDIT
As per the comment by #OscarPerpiñán, a better way to do this is:
spplot(pol) + as.layer(spplot(r), under = TRUE)
I have a few rasters I would like to plot using gplot in the rasterVis package. I just discovered gplot (which is fantastic and so much faster than doing data.frame(rasterToPoints(r))). However, I can't get a discrete image to show. Normally if r is a raster, I'd do:
rdf=data.frame(rasterToPoints(r))
rdf$cuts=cut(rdf$value,breaks=seq(0,max(rdf$value),length.out=5))
ggplot(rdf)+geom_raster(aes(x,y,fill=cuts))
But is there a way to avoid the call to rasterToPoints? It is very slow with large rasters. I did find I could do:
cuts=cut_interval(r#data#values,n=5)
but if you set the fill to cuts it plots the integer representation of the factors.
Here is some reproducible data:
x=seq(-107,-106,.1)
y=seq(33,34,.1)
coords=expand.grid(x,y)
rdf=data.frame(coords,depth=runif(nrow(coords),0,2)))
names(rdf)=c('x','y','value')
r=rasterFromXYZ(rdf)
Thanks
gplot is a very simple wrapper around ggplot so don't expect too
much from it. Instead, you can use part of its code to build your own
solution. The main point here is to use sampleRegular to reduce the
number of points to be displayed.
library(raster)
library(ggplot2)
x <- sampleRegular(r, size=5000, asRaster = TRUE)
dat <- as.data.frame(r, xy=TRUE)
dat$cuts <- cut(dat$value,
breaks=seq(0, max(dat$value), length.out=5))
ggplot(aes(x = x, y = y), data = dat) +
geom_raster(aes(x, y, fill=cuts))
However, if you are open to plot without ggplot2 you may find useful
this other
answer.
I am trying to use the animation package to generate an "evolving" plot of points on a map. The map is generated from shapefiles (from the readShapeSpatial/readShapeLines functions).
The problem is when it's plotted in a for loop, the result is additive, whereas the ideal result is to have it evolve.
Are there ways of using par() that I am missing?
My question is: is there a way to clear just the points ploted from the points function
and not clearing the entire figure thus not having to regraph the shapefiles?
in case someone wants to see code:
# plotting underlying map
newyork <- readShapeSpatial('nycpolygon.shp')
routes <- readShapeLines('nyc.shp')
par(bg="grey25")
plot(newyork, lwd=2, col ="lightgray")
plot(routes,add=TRUE,lwd=0.1,col="lightslategrey")
# plotting points and save to GIF
ani.options(interval=.05)
saveGIF({
par(bg="grey25")
# Begin loop
for (i in 13:44){
infile <-paste("Week",i,".csv",sep='')
mydata <-read.csv(file = infile, header = TRUE, sep=",")
plotvar <- Var$Para
nclr <- 4
plotclr <-brewer.pal(nclr,"RdPu")
class<- classIntervals(plotvar,nclr,style = "pretty")
colcode <- findColours(class,plotclr)
points(Var$Lon,Var$Lat,col=colcode)
}
})
If you can accept a residual shadow or halo of ink, you can over-plot with color ="white" or == to your background choices. We cannot access your shape file but you can try it out by adding this line:
points(Var$Lon, Var$Lat, col="grey25")
It may leave gaps in other previously plotted figures or boundaries, because it's definitely not object-oriented. The lattice and ggplot2 graphics models are more object oriented, so if you want to post a reproducible example, that might be an alternate path to "moving" forward. I seem to remember that the rgl package has animation options in its repetoire.