Clearing plotted points in R - r

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.

Related

Represent a colored polygon in ggplot2

I am using the statspat package because I am working on spatial patterns.
I would like to do in ggplot and with colors instead of numbers (because it is not too readable),
the following graph, produced with the plot.quadratest function: Polygone
The numbers that interest me for the intensity of the colors are those at the bottom of each box.
The test object contains the following data:
Test object
I have looked at the help of the function, as well as the code of the function but I still cannot manage it.
Ideally I would like my final figure to look like this (maybe not with the same colors haha):
Final object
Thanks in advance for your help.
Please provide a reproducible example in the future.
The package reprex may be very helpful.
To use ggplot2 for this my best bet would be to convert
spatstat objects to sf and do the plotting that way,
but it may take some time. If you are willing to use base
graphics and spatstat you could do something like:
library(spatstat)
# Data (using a built-in dataset):
X <- unmark(chorley)
plot(X, main = "")
# Test:
test <- quadrat.test(X, nx = 4)
# Default plot:
plot(test, main = "")
# Extract the the `quadratcount` object (regions with observed counts):
counts <- attr(test, "quadratcount")
# Convert to `tess` (raw regions with no numbers)
regions <- as.tess(counts)
# Add residuals as marks to the tessellation:
marks(regions) <- test$residuals
# Plot regions with marks as colors:
plot(regions, do.col = TRUE, main = "")

R rasterVis levelplot: a white line erroneously appears

I am plotting maps of atmospheric pollutant fields, or meteorological field, difference between such fields, often overlayed with orography.
My fields are gridded.
A white line misteriously appears, sometimes two.
This seems to happen a bit randomly. I mean: same code and fields, same line; but when I change fields, or color scales, it changes position, or it disappears, or another one appears. Sometimes horizontal, sometimes vertical.
Here is my code
#!/usr/bin/env Rscript
library(rasterVis)
library(RColorBrewer)
NX <- 468
NY <- 421
hgt <- matrix(0.,NX,NY)
# read from file:
ucon <- file("hgt.dat", open="rb")
for (n in seq(1,NX)) {
hgt[n,] <- readBin(ucon, "numeric", n=NY, size=4)
}
close(ucon)
hgtbks <- c(-100,10,500,1000,1500,2000,2500,3000,3500)
hgtcols <- colorRampPalette(c("gray30","white"))(length(hgtbks)-1)
tit <- "Orography"
bkstart=50.0; bkmax=1500.; bkby=100.
bks <- seq(bkstart, bkmax, bkby)
nbks <- length(bks)
cols <- rev(colorRampPalette(brewer.pal(11,"Spectral"))(nbks-2))
cols <- c("white",cols)
legendbreaks <- seq(1,nbks)
legendlabels <- formatC(bks,digits=3)
legendlabpos <- legendbreaks
rpl <-
levelplot(hgt, margin=FALSE , col.regions= hgtcols, at= hgtbks
, main= list(label=tit, cex=1.8)
, colorkey=list(draw= TRUE, col=cols, at=legendbreaks
, labels=list(labels=legendlabels, at=legendlabpos, cex=1.2))
, xlab=NULL, ylab=NULL, scales= list(draw= FALSE))
png("whiteline.png", width=800, height=840)
plot(rpl)
graphics.off()
I would really like to upload a file with my data, but for the moment
I could not find a way to do it (I don't think I can do it, not even an ASCII file). The data matrix (468x421) is too big to be explicitly included in the code, but it really is the orography file
shown in the picture (elevation in meters above mean sea level).
And here is the resulting "white line" map:
Really, I think this might be a levelplot bug. It seems to happen both when hgt is a matrix and when it is a proper raster object: this doesn't seem to make a difference.
Any idea?
I think I found a workaround.
By setting zero padding on the 4 sides, I managed to make the whiteline disappear from a series of maps.
First I defined:
zpadding <- list(layout.heights= list(top.padding=0, bottom.padding=0),
layout.widths= list(left.padding=0, right.padding=0))
then I added, among the parameters of the levelplot call:
par.settings=zpadding
As I said, I don't think this is a proper solution, but a workaround.
The problem seems related to any rescaling of the plot area.
In fact, when a rescaling is forced by, for example, having 4 or 5 digits (instead of 2 or 3) in the colorbar labels, a white line may reappear.
I hope this may point in the right direction other people, either users or developers of levelplot and related software.

Issue: ggplot2 replicates last plot of a list in grid

I have some 16 plots. I want to plot all of these in grid manner with ggplot2. But, whenever I plot, I get a grid with all the plots same, i.e, last plot saved in a list gets plotted at all the 16 places of grid. To replicate the same issue, here I am providing a simple example with two files. Although data are entirely different, but plots drawn are similar.
library(ggplot2)
library(grid)
library(gridExtra)
library(scales)
set.seed(1006)
date1<- as.POSIXct(seq(from=1443709107,by=3600,to=1446214707),origin="1970-01-01")
power <- rnorm(length(date1),100,5)#with normal distribution
write.csv(data.frame(date1,power),"file1.csv",row.names = FALSE,quote = FALSE)
# Now another dataset with uniform distribution
write.csv(data.frame(date1,power=runif(length(date1))),"file2.csv",row.names = FALSE,quote = FALSE)
path=getwd()
files=list.files(path,pattern="*.csv")
plist<-list()# for saving intermediate ggplots
for(i in 1:length(files))
{
dframe<-read.csv(paste(path,"/",files[i],sep = ""),head=TRUE,sep=",")
dframe$date1= as.POSIXct(dframe$date1)
plist[[i]]<- ggplot(dframe)+aes(dframe$date1,dframe$power)+geom_line()
}
grid.arrange(plist[[1]],plist[[2]],ncol = 1,nrow=2)
You need to remove the dframe from your call to aes. You should do that anyway because you have provided a data-argument. In this case it's even more important because while you save the ggplot-object, things don't get evaluated until the call to plot/grid.arrange. When you do that, it looks at the current value of dframe, which is the last dataset in your iteration.
You need to plot with:
ggplot(dframe)+aes(date1,power)+geom_line()

Plotting multiple charts based on stored functions

In R, I'm trying to plot multiple charts based on stored functions (I'm pretty new to programming with R, so that might not totally make sense). Basically, I've created some charts and stored them in a function that can be easily run with new data. I want to retain that functionality while adding the ability to render multiple charts in one render. I'd like it to end up something like this http://www.statmethods.net/advgraphs/images/layout1.jpg
I've run the code below, but it just produces multiple instances of each graph (or replaces each graph with the new rendering).
So my question is this: what am I doing wrong? Does anyone out there know how I can generate four graphs to be placed in one view (like the link above) using the following code and functions? Any help is greatly appreciated.
Note: the second bit of code has two siblings. I also have a pie chart I haven't included, but it's mentioned in the following code.
Here's the code I've been working with:
attach(ES)
par=(mfrow=c(2,2))
plot=(mapFunctionRead())
plot=(mapFunctionSkim())
plot=(mapFunctionDelete())
plot=(pieChart())
And Here's a sample function:
mapFunctionRead<-function(){
# draw world map
map(database="world", bg="#d4d5d1", fill = TRUE, col="#ffffff",myborder = 0)
################# For Read ####################
# Draw circles
symbols(mtReadLong, mtReadLat, circles=rep(1, length(mtReadLong)), inches=0.005, add=TRUE)
# assign numerical value that's based on the amount of time read
radiusRead<-sqrt(mtReadSec/pi)
# draw circles with fill and border
symbols(mtReadLong, mtReadLat, bg="#4173a5", fg="#5589c7", lwd=0.5, circles=radiusRead, inches=0.05, add=TRUE)
}
################# Displays data on world map for SKIM ######################
mapFunctionSkim<-function(){
# draw world map
map(database="world", bg="#d4d5d1", fill = TRUE, col="#ffffff",myborder = 0)
################# For Skim ####################
# Draw circles
symbols(mtSkimLong, mtSkimLat, circles=rep(1, length(mtSkimLong)), inches=0.005, add=TRUE)
# assign numerical value that's based on the amount of time read
radiusSkim<-sqrt(mtSkimSec/pi)
# draw circles with fill and border
symbols(mtSkimLong, mtSkimLat, bg="#ead57d", fg="#ead57d", lwd=0.5, circles=radiusSkim, inches=0.05, add=TRUE)
}
################# Displays data on world map for DELETE ######################
mapFunctionDelete<-function(){
# draw world map
map(database="world", bg="#d4d5d1", fill = TRUE, col="#ffffff",myborder = 0)
################# For Delete ####################
# Draw circles
symbols(mtDeleteLong, mtDeleteLat, circles=rep(1, length(mtDeleteLong)), inches=0.005, add=TRUE)
# assign numerical value that's based on the amount of time read
radiusDelete<-sqrt(mtDeleteSec/pi)
# draw circles with fill and border
symbols(mtDeleteLong, mtDeleteLat, bg="#77223c", fg="#9c1b3e", lwd=0.5, circles=radiusDelete, inches=0.05, add=TRUE)
}
Well I agree with #MrFlick. You might want to think of providing arguments to your map functions. For example.
library(maps)
mfunc <- function(x,y){
map(database = x, bg = y)
}
mfunc(x = "world", y = "#d4d5d1")
Then once all your map functions are defined you can use par(mfrow = c(a,b)). But just based on the info you have provided I'm not really sure what you want. Best of luck though.

rCharts Polychart: Adding horizontal or vertical lines to a plot

I'm having some trouble understanding how to customize graphs using the rPlot function in the rCharts Package. Say I have the following code
#Install rCharts if you do not already have it
#This will require devtools, which can be downloaded from CRAN
require(devtools)
install_github('rCharts', 'ramnathv')
#simulate some random normal data
x <- rnorm(100, 50, 5)
y <- rnorm(100, 30, 2)
#store in a data frame for easy retrieval
demoData <- data.frame(x,y)
#generate the rPlot Object
demoChart <- rPlot(y~x, data = demoData, type = 'point')
#return the object // view the plot
demoChart
This will generate a plot and that is nice, but how would I go about adding horizontal lines along the y-axis? For example, if I wanted to plot a green line which represented the average y-value, and then red lines which represented +/- 3 standard deviations from the average? If anybody knows of some documentation and could point me to it then that would be great. However, the only documentation I could find was on the polychart.js (https://github.com/Polychart/polychart2) and I'm not quite sure how to apply this to the rCharts rPlot function in R.
I have done some digging and I feel like the answer is going to have something to do with adding/modifying the layers parameter within the rPlot object.
#look at the slots in this object
demoChart$params$layers
#doing this will return the following output (which will be different for
#everybody because I didn't set a seed). Also, I removed rows 6:100 of the data.
demoChart$params$layers
[[1]]
[[1]]$x
[1] "x"
[[1]]$y
[1] "y"
[[1]]$data
x y
1 49.66518 32.75435
2 42.59585 30.54304
3 53.40338 31.71185
4 58.01907 28.98096
5 55.67123 29.15870
[[1]]$facet
NULL
[[1]]$type
[1] "point"
If I figure this out I will post a solution, but I would appreciate any help/advice in the meantime! I don't have much experience playing with objects in R. I feel like this is supposed to have some similarity to ggplot2 which I also don't have much experience with.
Thanks for any advice!
You can overlay additional graphs onto your rCharts plot using layers. Add values for any additional layers as columns on to your original data.frame. copy_layer lets you use the values from the data.frame in the extra layers.
# Regression Plots using rCharts
require(rCharts)
mtcars$avg <- mean(mtcars$mpg)
mtcars$sdplus <- mtcars$avg + sd(mtcars$mpg)
mtcars$sdneg <- mtcars$avg - sd(mtcars$mpg)
p1 <- rPlot(mpg~wt, data=mtcars, type='point')
p1$layer(y='avg', copy_layer=T, type='line', color=list(const='red'))
p1$layer(y='sdplus', copy_layer=T, type='line', color=list(const='green'))
p1$layer(y='sdneg', copy_layer=T, type='line', color=list(const='green'))
p1
Here are a couple of examples: one from the main rCharts website and the other showing how to overlay a regression line.

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