In ggplot2, one can easily save a graphic into a R object.
p = ggplot(...) + geom_point() # does not display the graph
p # displays the graph
The standard function plot produces the graphic as a void function and returns NULL.
p = plot(1:10) # displays the graph
p # NULL
Is it possible to save a graphic created by plot in an object?
base graphics draw directly on a device.
You could use
1- recordPlot
2- the recently introduced gridGraphics package, to convert base graphics to their grid equivalent
Here's a minimal example,
plot(1:10)
p <- recordPlot()
plot.new() ## clean up device
p # redraw
## grab the scene as a grid object
library(gridGraphics)
library(grid)
grid.echo()
a <- grid.grab()
## draw it, changes optional
grid.newpage()
a <- editGrob(a, vp=viewport(width=unit(2,"in")), gp=gpar(fontsize=10))
grid.draw(a)
I am very late to this, but it was the first question which showed up when I searched for the question. So I'd like to add my solution for future viewers who come across the question.
I solved this by using a function instead of an object. For example, suppose we want to compare two beta distributions with different parameters. We can run:
z1<-rbeta(10000,5,5)
z2<-rbeta(10000,20,20)
plotit<-function(vector,alpha,beta){
plot(density(vector),xlim=c(0,1))
abline(v=alpha/(alpha+beta),lty="longdash")
}
And save the plots as functions rather than objects.
z.plot1<-function(){plotit(z1,5,5)}
z.plot2<-function(){plotit(z2,20,20)}
Next, we can call each plot as we want by simply calling the two plots as functions rather than objects.
z.plot1()
plots the first plot and
z.plot2()
plots the second.
Hope that helps someone who stumbles across this later!
You can use the active binding feature of the pryr package if you don't want to directly change the values of the object created.
library(pryr)
a %<a-% plot(1:10,1:10)
Each time you type a on the console the graph will be reprinted on the screen. The %<a-% operator will rerun the script every time (in case of one graph this is not a problem I think). So essentially every time you use a the code will be rerun resulting in your graph which of course you can manipulate (overlay another plot on top) or save using png for example. No value itself will be stored in a however. The value will still be NULL.
I don't know if the above is what you are looking for but it might be an acceptable solution.
library(ggplot2)
# if mygraph is a plot object
ggsave("myplot1.png",mygraph)
# if the plot is in a list (e.g. created by the Bibliometrics package)
ggsave("myplot1.png",mygraphs[[1]])
Related
In ggplot2, one can easily save a graphic into a R object.
p = ggplot(...) + geom_point() # does not display the graph
p # displays the graph
The standard function plot produces the graphic as a void function and returns NULL.
p = plot(1:10) # displays the graph
p # NULL
Is it possible to save a graphic created by plot in an object?
base graphics draw directly on a device.
You could use
1- recordPlot
2- the recently introduced gridGraphics package, to convert base graphics to their grid equivalent
Here's a minimal example,
plot(1:10)
p <- recordPlot()
plot.new() ## clean up device
p # redraw
## grab the scene as a grid object
library(gridGraphics)
library(grid)
grid.echo()
a <- grid.grab()
## draw it, changes optional
grid.newpage()
a <- editGrob(a, vp=viewport(width=unit(2,"in")), gp=gpar(fontsize=10))
grid.draw(a)
I am very late to this, but it was the first question which showed up when I searched for the question. So I'd like to add my solution for future viewers who come across the question.
I solved this by using a function instead of an object. For example, suppose we want to compare two beta distributions with different parameters. We can run:
z1<-rbeta(10000,5,5)
z2<-rbeta(10000,20,20)
plotit<-function(vector,alpha,beta){
plot(density(vector),xlim=c(0,1))
abline(v=alpha/(alpha+beta),lty="longdash")
}
And save the plots as functions rather than objects.
z.plot1<-function(){plotit(z1,5,5)}
z.plot2<-function(){plotit(z2,20,20)}
Next, we can call each plot as we want by simply calling the two plots as functions rather than objects.
z.plot1()
plots the first plot and
z.plot2()
plots the second.
Hope that helps someone who stumbles across this later!
You can use the active binding feature of the pryr package if you don't want to directly change the values of the object created.
library(pryr)
a %<a-% plot(1:10,1:10)
Each time you type a on the console the graph will be reprinted on the screen. The %<a-% operator will rerun the script every time (in case of one graph this is not a problem I think). So essentially every time you use a the code will be rerun resulting in your graph which of course you can manipulate (overlay another plot on top) or save using png for example. No value itself will be stored in a however. The value will still be NULL.
I don't know if the above is what you are looking for but it might be an acceptable solution.
library(ggplot2)
# if mygraph is a plot object
ggsave("myplot1.png",mygraph)
# if the plot is in a list (e.g. created by the Bibliometrics package)
ggsave("myplot1.png",mygraphs[[1]])
So, I want to plot multiple polygons over one polygon using a loop in r. I have read that you need to use print in order to succesively display the polygons over the original polygon. However, that is not what R seems to do. Besides, in a hardly reproducible example, what i find is that either using print or not, the polygons will not plot within the loop. I am using a mac with OS monterrey, btw.
Here is a reproducible example, using print gives a bunch of NULL messages, but does print, not using print still plots. Yet a more complicated example will never plot from within the loop despite plotting everything when i request line by line from within the loop.
require(maptools)
data(wrld_simpl)
plot(wrld_simpl)
for (i in 1:12){
region=wrld_simpl[wrld_simpl$NAME==wrld_simpl$NAME[i],]
print(plot(region,border="red",add=T))
}
Maybe you're confusing print and plot? The plot function creates (or adds elements to) a plot. Whereas print function prints its arguments to the console. Since plot doesn't return a value, print has nothing to print and hence prints NULL.
Btw. you don't even need a loop. Since the loaded data wrld_simpl is of class SpatialPolygonsDataFrame, the object is subsettable like a dataframe you can just plot the needed indices:
plot(wrld_simpl)
plot(wrld_simpl[1:12,], border="red", add=T)
If you need help on a more complicated example, I suggest you share it?
I am very new to R, so I apologize if this is a basic question.
Is there any way to have the data behind the graph the function "hist" produces?
I don't need the graphic, I just the data.
In general, it would be nice if I have the option to only get the data behind the functions that produce graphs and prevent drawing the actual plots.
Thank you,
There is no way to obtain the original data behind the function hist.
If you are referring just to the data required to generate the plot, they are stored in hist(x)$mids and hist(x)$count, which contains respectively the midpoints and the counts. If you want just the data without drawing the plot, you can call this function on the object hist:
dataHist<-function(y){
rbind(y$mids,y$counts)
}
Try using hist(*yourvectorname*, plot = FALSE)
I'm trying to make multiple plots with the following code. (da.list is a list of xts objects, and chart_Series is a plotting function from the quantmod package.)
library(quantmod)
plotLoan = function(loanID){
chart_Series( da.list[[loanID]], name = paste0('Loan ID: ', loanID))
}
LoanIDs = sample(names(da.list),6)
for (LoanID in LoanIDs) plotLoan(LoanID)
I'm not getting any output. However, plotLoan(LoanIDs[1]) produces a plot as expected. Why won't this work in a loop?
Have you tried using the layout command? Not sure exactly what's going on but I expect it has something to do with not having enough room in the graphics device. You can try
layout(matrix(seq(6), nrow=3, ncol=2))
layout.show(6)
which will partition the graphics output and show where the next 6 plots will go. If you want to produce a different number of plots you will have to choose the dimensions based on your needs.
In ggplot2, one can easily save a graphic into a R object.
p = ggplot(...) + geom_point() # does not display the graph
p # displays the graph
The standard function plot produces the graphic as a void function and returns NULL.
p = plot(1:10) # displays the graph
p # NULL
Is it possible to save a graphic created by plot in an object?
base graphics draw directly on a device.
You could use
1- recordPlot
2- the recently introduced gridGraphics package, to convert base graphics to their grid equivalent
Here's a minimal example,
plot(1:10)
p <- recordPlot()
plot.new() ## clean up device
p # redraw
## grab the scene as a grid object
library(gridGraphics)
library(grid)
grid.echo()
a <- grid.grab()
## draw it, changes optional
grid.newpage()
a <- editGrob(a, vp=viewport(width=unit(2,"in")), gp=gpar(fontsize=10))
grid.draw(a)
I am very late to this, but it was the first question which showed up when I searched for the question. So I'd like to add my solution for future viewers who come across the question.
I solved this by using a function instead of an object. For example, suppose we want to compare two beta distributions with different parameters. We can run:
z1<-rbeta(10000,5,5)
z2<-rbeta(10000,20,20)
plotit<-function(vector,alpha,beta){
plot(density(vector),xlim=c(0,1))
abline(v=alpha/(alpha+beta),lty="longdash")
}
And save the plots as functions rather than objects.
z.plot1<-function(){plotit(z1,5,5)}
z.plot2<-function(){plotit(z2,20,20)}
Next, we can call each plot as we want by simply calling the two plots as functions rather than objects.
z.plot1()
plots the first plot and
z.plot2()
plots the second.
Hope that helps someone who stumbles across this later!
You can use the active binding feature of the pryr package if you don't want to directly change the values of the object created.
library(pryr)
a %<a-% plot(1:10,1:10)
Each time you type a on the console the graph will be reprinted on the screen. The %<a-% operator will rerun the script every time (in case of one graph this is not a problem I think). So essentially every time you use a the code will be rerun resulting in your graph which of course you can manipulate (overlay another plot on top) or save using png for example. No value itself will be stored in a however. The value will still be NULL.
I don't know if the above is what you are looking for but it might be an acceptable solution.
library(ggplot2)
# if mygraph is a plot object
ggsave("myplot1.png",mygraph)
# if the plot is in a list (e.g. created by the Bibliometrics package)
ggsave("myplot1.png",mygraphs[[1]])