R, how to use pch with time series plot - r

I would like to plot a time series (meaning line graph with x axis as time) and specify a plotting character to use. None of the following has worked
a1 = as.xts(ts(c(5,3,7,2,4,8,3), start=c(1980,1), freq=4))
library('lattice')
xyplot(a1, col="red", pch=2)
xyplot(a1, col="red", par.settings = list(superpose.symbol = list(col = 1, pch = 2)),)
ts.plot(ts(a1), pch=2)
plot(a1, phc=2)
I would prefer a lattice solution, but would accept any solution if lattice can not do this.

By default, time series plots in R use type = "l", which means that you get a line but no point characters. To get both, you can change your type to "b".
xyplot(a1, col = "red", pch = 2, type = "b")
This yields:
The same logic applies to the base plot function; simply add type = "b".

Related

Why "plot" doesn't display the line?

I have this plot that it's creating me some problems as I don't manage to plot the red line between CIs. This plot is the fifth of a series of plots that are identical in nature and code. Only in this case, the line doesn't show up. I can't figure it out why.
This is my dataset and code:
ap_pp = structure(list(appp = c(0.0534256470459521, 0.318338283911788,
0.510498594892796, 0.659918013907143, 0.847855923395071, 1.33512933449448,
1.79114871626335), LB_T = c(-0.0039953960988687, -0.00128119112255898,
1.231602663197e-05, 0.000409544070864543, 0.00117091129359269,
0.00719127778296817, 0.0141800410470155), UB_T = c(0.00506390903978775,
0.00764795680079474, 0.010197655871224, 0.0127888162072783, 0.0157862071743087,
0.0195113089069214, 0.0216429332782514), LB_T = c(-0.0039953960988687,
-0.00128119112255898, 1.231602663197e-05, 0.000409544070864543,
0.00117091129359269, 0.00719127778296817, 0.0141800410470155),
UB_T = c(0.00506390903978775, 0.00764795680079474, 0.010197655871224,
0.0127888162072783, 0.0157862071743087, 0.0195113089069214,
0.0216429332782514)), class = "data.frame", row.names = c(NA,
-7L))
plot(ap_pp$appp, ylim = range(c(ap_pp$LB_T, appp$UB_T)), xlab = "", ylab = "", main = "LSAP", type = "n", xaxt = "n")
axis(1, at = 1:7, labels = load_unscaled_m$Date)
with(ap_pp, polygon(c(xx,rev(xx)),c(LB_T,rev(UB_T)), col = "#FFA6AA", border = FALSE))
abline(h = 0, col = "black", lty = 2)
lines(ap_pp$appp, type = "o", lwd = 2, col = "red")
Can anyone help me?
Thanks
You have some issues:
Typo, you use appp$UB_T in the range(), which doesn't exist. You need ap_pp$UB_T
Range. The line data you are trying to plot has a minimum of 0.05:
range(ap_pp$appp)
[1] 0.05342565 1.79114872
However, you set the y-axis to have a maximum of 0.02:
range(c(ap_pp$LB_T, ap_pp$UB_T))
[1] -0.003995396 0.021642933
Since the maximum of your y axis, 0.0216, is less than the minimum of the data you are plotting, 0.0534, all the points you are trying to plot are "above" the graph.
Graph type. You say "line", but by default plot will plot points. If you want a line, use type = "l". (Or lines(), as you do later.)
I have no idea what xx is, so I don't know what's going on with your polygon code. But presumably the y limits are again defined by UB_T and LB_T, and so the maximum of the y axis is still lower than the minimum of the data in lines()
Duplicate column names are a bad idea. You have two columns named LB_T and two named UB_T. They appear to be identical, which is less bad than if they were different, but I would strongly suggest not using duplicate column names so there is no ambiguity about which column you are referring to.
Perhaps you should include ap_pp$ppp in the range call.

Plotting in R using plot function

I am trying to plot few graphs using loops. I am now describing in details.
First I have a function which is calculates the y-variable (called effect for vertical axis)
effect<- function (x, y){
exp(-0.35*log(x)
+0.17*log(y)
-0.36*sqrt(log(x)*log(y)/100))
}
Now I run the following code and use the option par to plot the lines in the same graph. I use axis=FALSE and xlab="" to get a plot without labels. I do this so that my labels are not re-written each time the loop runs and looks ugly.
for (levels in seq(exp(8), exp(10), length.out = 5)){
x = seq(exp(1),exp(10), length.out = 20)
prc= effect(levels,x)
plot(x, prc,xlim = c(0,max(x)*1.05), ylim=c(0.0,0.3),
type="o", xlab = "",ylab = "", pch = 16,
col = "dark blue", lwd = 2, cex = 1, axes = F)
label = as.integer(levels) #x variable
text(max(x)*1.03,max(prc), label )
par(new=TRUE)
}
Finally, I duplicate the plot command this time using the xlab and ylab options
plot(x, prc, xlab = "X-label", ylab = "effect",
xlim = c(0,max(x)*1.05), ylim = c(0,0.3),
type="l", col ='blue')
I have several other plots in the similar lines, using complex equations. I have two questions:
Is there an better option to have the same plot with smoother lines?
Is there an easier option with few lines to achieve the same, where I can place the texts (levels) for each line on the right with white background at the back?
I believe working with the plot function was tedious and time consuming. So, I have finally used ggplot2 to plot. There were several help available online, which I have used.

Legend appears, but it does not show color

I am using R for plotting. When my graph plots the legend appears where I want it to be but the colors are missing. mtcars 2 is a modified version of mtcars (one of the pre-loaded data sets) that adds a model and country of origin to the data set. mtcars.pca is what I named my redundance analysis (rda function under vegan), and mtcars.clust is titled for hierarchical clustering of the continuous factors of mtcars (hclust function of vegan) Below is the code I am using with mtcars2.
pca.fig = ordiplot(mtcars.pca, type = "none", las=1, xlim=c(-15,15), ylim = c(-20,10))
points(pca.fig, "sites", pch = 19, col = "green", select = mtcars2$origin =="domestic")
points(pca.fig, "sites", pch = 19, col = "blue", select = mtcars2$origin =="foreign")
ordiellipse(mtcars.pca, mtcars2$origin, conf = 0.95, label = FALSE)
ordicluster(mtcars.pca, mtcars.clust, col = "gray")
legend("bottomright", title="Car Origin", c("domestic", "foreign"), col = "origin")
You need to specify a vector of colours in legend and also a pch:
library("vegan")
data(dune, dune.env)
ord <- rda(dune)
plot(ord, type = "n")
cols <- c("red","blue","green")
points(ord, col = cols[dune.env$Use], pch = 19)
legend("bottomright", legend = levels(dune.env$Use), bty = "n",
col = cols, pch = 19)
If you don't add pch but just use col = cols legend() doesn't display any points. Because you used pch = 19 in your points() calls, use the same in the legend() call.
Also, note how to plot points of different colours in a single pass. I have some examples and explanation that go through the indexing trick I used in my code above to achieve this in a blog post of mine from a few years ago: http://www.fromthebottomoftheheap.net/2012/04/11/customising-vegans-ordination-plots/
I came to this question having the next problem in xts object:
I wanted to plot all time-series in xts object with legend. Moreover, there were around 20.
I used (wrong):
plot(returns_xts)
addLegend(...)
Correct version:
plot(returns_xts, legend.loc = "bottomright", col=1:20, lty = 1)
There is legend.loc parameter
col = 1:20 generates colors for you
Result:

Plot line of a function in R

I have the following script:
FGM = function (n,r,z){
x = r*sqrt(n)/(2*z)
Px = 1-pnorm(x)
}
re = 10000
data = data.frame(abs(rnorm(re,0,1)), abs(rnorm(re,0,1)), abs(rnorm(re,0,1)))
colnames(data) = c("n","r","z")
data$Px = FGM(data$n,data$r,data$z)
data$x = data$r*sqrt(data$n)/(2*data$z)
par(mar=c(4.5,4.5,1,1))
plot(data$x,data$Px, xlim = c(0,3), pch = 19, cex = 0.1, xaxs="i", yaxs="i",
xlab = expression(paste("Standardized mutational size (",italic(x), ")")),
ylab = expression(paste("P"[a],"(",italic(x),")")))
Which is a recreation of the graph found here (box 2). You can see in this script that I do this by just plotting 10000 small black points with various values of n,z, and r. This seems like an ugly work around, I think I should just be able to give R my function
FGM = function (n,r,z){
x = r*sqrt(n)/(2*z)
Px = 1-pnorm(x)
}
and have it plot a line on a graph. However, a few hours of scouring the web has been unproductive, and I tried a few ways with abline and lines but nothing worked, is there a way of doing it with these functions or another function?
Tried this...
plot(data$x,data$Px, xlim = c(0,3), ylim = c(0,0.5), xaxs="i", yaxs="i",
xlab = expression(paste("Standardized mutational size (",italic(x), ")")),
ylab = expression(paste("P"[a],"(",italic(x),")")), type = "n")
curve(1-pnorm(r*sqrt(n)/(2*z)), add=T)
>Error in curve(1 - pnorm(r * sqrt(n)/(2 * z)), add = T) :
'expr' must be a function, or a call or an expression containing 'x'
>
#PaulRegular offered this solution but it still plots based on data, not the formula itself. I'm looking for a solution which can produce the curve properly without large values of "re" - using the following but with "re" set to 10 you can see what I mean...
data <- data[order(data$x),]
lines(data$x, data$Px, lwd=1)
You can pass a function of just one variable to plot. I guess that you are looking for:
plot(function(x) 1-pnorm(x),0,3)
Try sorting your data by x, then add the line:
data <- data[order(data$x),]
lines(data$x, data$Px, lwd=2)

R legend issue, symbols of points are masked by lines

Is there a way to draw the lines in such a way that they would start on the side of the points, or allow the symbols to be in foreground?
My solution was to make the symbols bigger and more visible.
Edit 1: it's for plot {graphics} of the R program.
Edit 2: the code per popular request.
legend(2,.4,bty='n', c('sugar','citrus','none'), pch=c('s','c','u'), pt.bg='white',lty= c(1,2,3), lwd=1.5, title="Condition",pt.cex=c(1.5),cex=1.5)
Edit 3: This is solved for plot(type='b') but somehow not for legend.
Thanks for reading!
The only thing I can come up with is to manually finagle the dash lengths until they end up looking the way you want them. For instance, this:
> plot(1,1)
> legend(c("A", "B"), col = 1:2, x = 1, y = .8, lty="99", pch=1:2)
produces the image below.
The lty parameter allows you to specify the lengths of lines and dashes as hex characters. In this case, it's saying to create a line of length 9 then create a space of length 9 then repeat. It looks like 9 is about the best fit to space around a normal pch symbol.
Note that you'd probably need to adjust this depending on the size of the image, symbol, etc. My advice ultimately would be to export the image from R and touch up the image to meet your needs in graphic editing software.
Going with the suggestion by #JeffAllen, here is a way to get what I think you might want. It requires modifying the legend() function to return the position of the points (these are given by x1 and y1 in body(legend)[[46]]).
legend2 <- legend
body(legend2)[[49]] <- quote(
invisible(list(rect = list(w = w, h = h, left = left, top = top),
text = list(x = xt, y = yt), points = list(x = x1, y = y1)))
)
Make a plot:
plot(-100:100, -100:100, type = "b")
While drawing the legend, draw white circles (pch = 21 with pt.bg = 'white') over the lines, and assign the values invisibly returned by legend2() to an object. Note also the changes to pt.lwd and pt.cex.
myLegend <- legend2(1, .8, bty = 'n', c('sugar','citrus','none'), pch = 21,
pt.bg = 'white', pt.lwd = 0, lty = c(1, 2, 3), lwd = 1.5, title = "Condition",
pt.cex = c(1.8), cex = 1.5)
Finally, draw the characters you'd like to use in the legend using points(), supplying the x and y values from the object myLegend.
points(myLegend$points$x, myLegend$points$y, pch = c('s','c','u'), cex = 1.5)
And this should get you something like:
You could also use the filled points offered by R (pch=21:25) and specify the fill color using pc.bg which gets passed to the points call when creating a legend.
plot(1,1)
legend(c("A", "B"), col = 1:2, x = 1, y = .8, lty=1, pt.bg=1:2, pch=21:22)
generates the following:

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