size argument of plot() functio n in R - r

i have been searching for a while now but for some reason can't find the argument of the plot() function I can set the x&y dimensions of my plot with.
Does anyone know what i am looking for?
Just for clarification:
this is my plot() function so far:
plot(0,0,xlim=c(0,1),ylim=c(0.5,0.5+dim(RT)[1]),axes=FALSE,ylab="",xlab="")
and I would like to have sth of that sort:
plot(0,0,xlim=c(0,1),ylim=c(0.5,0.5+dim(RT)[1]),axes=FALSE,ylab="",xlab="", xsize = 10, ysize = 15)

One option is to set up the plot window first:
X11( height=5, width=10 )
plot( ... )

Related

Using user-defined functions within "curve" function in R graphics

I am needing to produce normally distributed density plots with different total areas (summing to 1). Using the following function, I can specify the lambda - which gives the relative area:
sdnorm <- function(x, mean=0, sd=1, lambda=1){lambda*dnorm(x, mean=mean, sd=sd)}
I then want to plot up the function using different parameters. Using ggplot2, this code works:
require(ggplot2)
qplot(x, geom="blank") + stat_function(fun=sdnorm,args=list(mean=8,sd=2,lambda=0.7)) +
stat_function(fun=sdnorm,args=list(mean=18,sd=4,lambda=0.30))
but I really want to do this in base R graphics, for which I think I need to use the "curve" function. However, I am struggling to get this to work.
If you take a look at the help file for ? curve, you'll see that the first argument can be a number of different things:
The name of a function, or a call or an expression written as a function of x which will evaluate to an object of the same length as x.
This means you can specify the first argument as either a function name or an expression, so you could just do:
curve(sdnorm)
to get a plot of the function with its default arguments. Otherwise, to recreate your ggplot2 representation you would want to do:
curve(sdnorm(x, mean=8,sd=2,lambda=0.7), from = 0, to = 30)
curve(sdnorm(x, mean=18,sd=4,lambda=0.30), add = TRUE)
The result:
You can do the following in base R
x <- seq(0, 50, 1)
plot(x, sdnorm(x, mean = 8, sd = 2, lambda = 0.7), type = 'l', ylab = 'y')
lines(x, sdnorm(x, mean = 18, sd = 4, lambda = 0.30))
EDIT I added ylab = 'y' and updated the picture to have the y-axis re-labeled.
This should get you started.

Color Individual Lines with Gadfly

Is there a way to color each dataset?
There is a solution using DataFrames, but what about cases without them?
I tried this, but it has no effect:
using Gadfly
plot(
layer(x=1:10, y=1:10, Stat.step, Geom.line),
layer(x=1:10, y=2:11, Stat.step, Geom.line),
color=["red", "green"]
)
Plotting should not be this painful. Here's how you do it in Plots using the Gadfly backend:
using Plots; gadfly(size=(400,300))
plot(rand(10,2), line = ([:red :green], :step))
#GnimucK. comment shows how to do this when you're working interactively. That method runs into a few difficulties though when you want to pass a colour in as an argument to a function. In the general case where I have multiple lines where I want the colors to be chosen at run-time, I have a function that looks a bit like what follows:
using Compose, Gadfly
function my_plot_with_colors{T<:Number}(x::Vector{Vector{T}}, y::Vector{Vector{T}}, colorVec::Vector{ASCIIString})
!(length(x) == length(y) == length(colorVec)) && error("Length mismatch in inputs")
layerArr = Array(Vector{Layer}, length(x))
for k = 1:length(x)
layerArr[k] = layer(x=x[k], y=y[k], Geom.line, Theme(default_color=parse(Compose.Colorant, colourVec[k])))
end
return(plot(layerArr...))
end
where, if length(x) = 3, your input vector colourVec would look something like this: ["red", "green", "blue"].

ggplot2: easy way to plot integral over independent variable?

I'm integrating a function f(t) = 2t (just an example) and would like to plot the integral as a function of time t using
awesome_thing <- function(t) {2*t}
integrate(awesome_thing, lower=0, upper=10)
However, I would like to plot the integral as a function of time in ggplot2, so for this example the plotted points would be (1,1), (2,4), (3,9), ..., (10,100).
Is there an easy way to do this in ggplot (e.g., something similar to how functions are plotted)? I understand I can "manually" evaluate and plot the data for each t, but I thought i'd see if anyone could recommend a simpler way.
Here is a ggplot solution and stat_function
# create a function that is vectorized over the "upper" limit of your
# integral
int_f <- Vectorize(function(f = awesome_thing, lower=0,upper,...){
integrate(f,lower,upper,...)[['value']] },'upper')
ggplot(data.frame(x = c(0,10)),aes(x=x)) +
stat_function(fun = int_f, args = list(f = awesome_thing, lower=0))
Not ggplot2 but shouldn't be difficult to adapt by creating a dataframe to pass to that paradgm:
plot(x=seq(0.1,10, by=0.1),
y= sapply(seq(0.1,10, by=0.1) ,
function(x) integrate(awesome_thing, lower=0, upper=x)$value ) ,
type="l")
The trick with the integrate function is that it retruns a list and you need to extract the 'value'-element for various changes in the upper limit.

Automatically update graph title with parameter

I am not very familiar with R. I was using R to make the poisson distribution plot for different lambda (from 1 to 10), and display the plot for each just as a comparison.
But I would like to add a title say: "lambda = 1" for plot 1, "lambda=2" for plot 2 ... etc on the graph automatically according to lambda. But I wasn't able to figure out how to update the title automatically. This is my code, I was able to output 10 different graph correctly , but not sure how to update or add the corresponding lambda to the title automatically. Could someone give me some hint.
Also is it possible to say have a font size of "small" for the plot 1 to 5, and then a font size of 6 to 10?
Thanks
the_data_frame<-data.frame(matrix(ncol=10,nrow=21))
lam<-seq(1,10,1)
lam
x<-seq(0,20,1)
x
for (i in 1:10){
the_data_frame[i]<-exp(-lam[i])*lam[i]**x/gamma(x+1)
}
the_data_frame<-cbind(the_data_frame, x)
par(mfrow=c(5,2))
for (i in 1:10){
plot(the_data_frame[[i]]~the_data_frame[[11]], the_data_frame)
}
You can simplify the problem. Using one loop, over the lamda values, you compute at each iteration the value of y using the poison formula then you plot it. I use main argument to add a title for each plot. Here I am using bquote to get a plotmath format of lambda value.
For example , for 4 values of lambda , you get:
x<-seq(0,20,1);lam = c(0.5,1,2,4)
par(mfrow=c(2,2))
lapply(lam,function(lamd){
y <- exp(-lamd)*lamd*x/gamma(x+1)
plot(x,y,main=bquote(paste(lambda,'=',.(lamd))),type='l')
})
This might help:
for (i in 1:10){
plot(the_data_frame[[i]]~the_data_frame[[11]], the_data_frame,
main=paste("lambda=", i, sep=""))
}
library(ggplot2)
xval <- rep(0:20,10)
lambda <- rep(1:10,21)
yvtal <- exp(- lambda)*lambda**xval/gamma(xval+1)
the_new_data_frame <- data.frame(cbind(xval,lambda,yval))
plot1 <- ggplot(the_new_data_frame, aes(xval, yval)) + geom_line(aes(colour=factor(lambda)))
plot1
plot1 + facet_grid(~lambda)
Were you looking for an interactive window where you can input the text and update the figure title? If yes you may want to look for the tcltk package.
See
http://bioinf.wehi.edu.au/~wettenhall/RTclTkExamples/modalDialog.html

superpose a histogram and an xyplot

I'd like to superpose a histogram and an xyplot representing the cumulative distribution function using r's lattice package.
I've tried to accomplish this with custom panel functions, but can't seem to get it right--I'm getting hung up on one plot being univariate and one being bivariate I think.
Here's an example with the two plots I want stacked vertically:
set.seed(1)
x <- rnorm(100, 0, 1)
discrete.cdf <- function(x, decreasing=FALSE){
x <- x[order(x,decreasing=FALSE)]
result <- data.frame(rank=1:length(x),x=x)
result$cdf <- result$rank/nrow(result)
return(result)
}
my.df <- discrete.cdf(x)
chart.hist <- histogram(~x, data=my.df, xlab="")
chart.cdf <- xyplot(100*cdf~x, data=my.df, type="s",
ylab="Cumulative Percent of Total")
graphics.off()
trellis.device(width = 6, height = 8)
print(chart.hist, split = c(1,1,1,2), more = TRUE)
print(chart.cdf, split = c(1,2,1,2))
I'd like these superposed in the same frame, rather than stacked.
The following code doesn't work, nor do any of the simple variations of it that I have tried:
xyplot(cdf~x,data=cdf,
panel=function(...){
panel.xyplot(...)
panel.histogram(~x)
})
You were on the right track with your custom panel function. The trick is passing the correct arguments to the panel.- functions. For panel.histogram, this means not passing a formula and supplying an appropriate value to the breaks argument:
EDIT Proper percent values on y-axis and type of plots
xyplot(100*cdf~x,data=my.df,
panel=function(...){
panel.histogram(..., breaks = do.breaks(range(x), nint = 8),
type = "percent")
panel.xyplot(..., type = "s")
})
This answer is just a placeholder until a better answer comes.
The hist() function from the graphics package has an option called add. The following does what you want in the "classical" way:
plot( my.df$x, my.df$cdf * 100, type= "l" )
hist( my.df$x, add= T )

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