Plotting 3D Surface Chart - r

I'm new to R and am trying to plot a 3D surface. I thought it would be a pretty simple process as I have all my data in a nice table but can't figure out where I'm going wrong.
my_data2 (read in from Excel):
X1 X1.1 X1.21 X1.33 X1.46 X1.61 X1.77 X1.98 X2.14 X2.35
4e+05 291208737 291296846 291744988 292676157 304539662 347763047 346637087 352381080 361467196 334153676
5e+05 301234194 301322304 342042259 344633543 346394275 347763047 392216772 376048898 361467196 334153676
The first column is my row headers.
I've tried a few different R packages but am obviously missing something.
I thought it would be as simple as:
> r <- 1:nrow(my_data2)
> c <- 1:ncol(my_data2)
> z <- c(my_data2)
> contour3D(x=r, y=c, z=z, colvar=Volcano)
Error message displayed: "exactly one of the values 'x' 'y', or 'z' should be a matrix or one value"
I thought my z variable was a matrix!
Can anyone please help?
Tks

from the help page: "contour3D adds a contour in a 3-D plot." So I think you actually want something else. Maybe something like this:
library(plot3D)
z <- as.matrix(my_data2)
hist3D(z=z)

Related

R: Problems while plotting sampled values from a curve

I am trying to simulate a signal in order to apply some methods of non-linear fittings, but I have some problems when plotting it.
x<-sample(seq(0,1,length.out = 1000),200)
y<-2*sin(4*pi*x)-6*abs(x-0.4)^(0.3)+2*exp(-30*(4*x-2)^2)+8*x+rnorm(200,0,0.5)
s<-2*sin(4*pi*x)-6*abs(x-0.4)^(0.3)+2*exp(-30*(4*x-2)^2)+8*x
plot(x,y)
lines(x,s,col="red")
The idea I want to have 200 observations uniformly sampled with an additive white noise term, and the I would like to plot this "perturbed" signal together with the original signal. (y and s respectively).
The fact is that if I use the code that I wrote I obtain as result something like:
Probably is such a simple thing, but I'm kinda stuck with this.
Any hint or suggestion will be greatly appreciated.
Lines are plotted sequentially, and you decided to randomly draw your X values, so x values sitting next to each other in x are not next to each other on the axis - hence the mess. Just sort it:
x<-sort(sample(seq(0,1,length.out = 1000),200))
y<-2*sin(4*pi*x)-6*abs(x-0.4)^(0.3)+2*exp(-30*(4*x-2)^2)+8*x+rnorm(200,0,0.5)
s<-2*sin(4*pi*x)-6*abs(x-0.4)^(0.3)+2*exp(-30*(4*x-2)^2)+8*x
plot(x,y)
lines(x,s,col="red")
Another way to do this on the fly mentioned by mickey is:
ord = order(x)
lines(x[ord], s[ord], col = 'red')
You need to reorder the x observations order in ascending order, you can do that by storing everything in a dataframe object and then ordering it:
x<-sample(seq(0,1,length.out = 1000),200)
df_p= data.frame(x)
df_p$y<-2*sin(4*pi*df_p$x)-6*abs(df_p$x-0.4)^(0.3)+2*exp(-30*(4*df_p$x-2)^2)+8*df_p$x+rnorm(200,0,0.5)
df_p$s<-2*sin(4*pi*df_p$x)-6*abs(df_p$x-0.4)^(0.3)+2*exp(-30*(4*df_p$x-2)^2)+8*df_p$x
df_p = df_p[order(df_p$x),]
plot(df_p$x,df_p$y)
lines(df_p$x, df_p$s,col="red")
Also if you want to avoid this step you can use the ggplot2 library:
p <- ggplot(df_p) + geom_point(aes(x = x,y= y)) + geom_line(aes(x=x,y=s,color='red'))
plot(p)

R: custom ggplot2 color-transform gives error in labels

Basically, i have a dataframe with 3 numeric vectors(x,y,z), and lets say i wanna make a scatter plot of x,y colored by z. I want to transform the colorscale with a squareroot that respects sign, so i made my own with trans_new. Here is a simple dataset, but with the actual transform.
library(ggplot2)
library(scales)
set.seed(1)
plot<-data.frame(x=rnorm(100),y=rnorm(100),z=rnorm(100))
super_trans <- function(){
trans_new('super', function(X) sapply(X,function(x) {if(x>0){x^0.5} else{-(- x)^0.5}}), function(X) sapply(X,function(x){ if(x>0){x^2} else{-x^2}}))
}
ggplot(plot,aes(x,y))+geom_point(aes(colour=z))+scale_colour_gradient(trans="super")
It gives an error,
Error in if (x > 0) { : missing value where TRUE/FALSE needed
I don't understand it. I tried to backtrack the mistake, and my guess is that the error happens when trans_new tries to make breaks.
However, i do not understand how the "breaks" parameter works in trans_new.
Is there a ggplot2/Scales hero out there, that can help me transform my color-scale correctly?
It may be relevant that only some datasets gives errors.
There is a vectorized if, called ifelse. It also seems you are missing an extra minus.
super_trans <- function() {
trans_new('super',
function(x) ifelse(x>0, x^0.5, -(-x)^0.5),
function(x) ifelse(x>0, x^2, -(-x)^2))
}

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.

Add to ggplot with element of different length

I'm new to ggplot2 and I'm trying to figure out how I can add a line to an already existing plot I created. The original plot, which is the cumulative distribution of a column of data T1 from a data frame x, has about 100,000 elements in it. I have successfully plotted this using ggplot2 and stat_ecdf() with the code I posted below. Now I want to add another line using a set of (x,y) coordinates, but when I try this using geom_line() I get the error message:
Error in data.frame(x = c(0, 7.85398574631245e-07, 3.14159923334398e-06, :
arguments imply differing number of rows: 1001, 100000
Here's the code I'm trying to use:
> set.seed(42)
> x <- data.frame(T1=rchisq(100000,1))
> ps <- seq(0,1,.001)
> ts <- .5*qchisq(ps,1) #50:50 mixture of chi-square (df=1) and 0
> p <- ggplot(x,aes(T1)) + stat_ecdf() + geom_line(aes(ts,ps))
That's what produces the error from above. Now here's the code using base graphics that I used to use but that I am now trying to move away from:
plot(ecdf(x$T1),xlab="T1",ylab="Cum. Prob.",xlim=c(0,4),ylim=c(0,1),main="Empirical vs. Theoretical Distribution of T1")
lines(ts,ps)
I've seen some other posts about adding lines in general, but what I haven't seen is how to add a line when the two originating vectors are not of the same length. (Note: I don't want to just use 100,000 (x,y) coordinates.)
As a bonus, is there an easy way, similar to using abline, to add a drop line on a ggplot2 graph?
Any advice would be much appreciated.
ggplot deals with data.frames, you need to make ts and ps a data.frame then specify this extra data.frame in your call to geom_line:
set.seed(42)
x <- data.frame(T1=rchisq(100000,1))
ps <- seq(0,1,.001)
ts <- .5*qchisq(ps,1) #50:50 mixture of chi-square (df=1) and 0
tpdf <- data.frame(ts=ts,ps=ps)
p <- ggplot(x,aes(T1)) + stat_ecdf() + geom_line(data=tpdf, aes(ts,ps))

'x' is a list, but does not have components 'x' and 'y'

i am trying to plot a ROC curve for a multiclass problem, using multiclass.roc function from pROC package, but I get this error:
'x' is a list, but does not have components 'x' and 'y'
What does this error mean cause searching in the web didn't help me to find an answer. I can print the roc object, but can not plot it.
Thank you!
If you call plot on a list l: plot (l), the x coordinates will be taken from l$x and the y coordinates from l$y. Your list doesn't have elements x and y.
You need to call plot (l$your.x.coordinate, l$your.y.coordinate) instead.
Another (lazy) approach is to simply use the useful library
install.packages('useful')
library(useful)
Example -
wineUrl <- 'http://archive.ics.uci.edu/ml/machine-learning-databases/wine/wine.data'
wine <- read.table(wineUrl, header=F, sep=',')
wine_kmeans <- wine[, which(names(wine) != "Cultivar")]
wine_cluster <- kmeans(x=wine_kmeans , centers=3)
plot(wine_cluster, data=wine_kmeans)

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