paired segments in ggplot - r

Given foo I'd like to connect pairs of points so that there is a line between foo[1,] and foo[11,], foo[2,] and foo[12,], up to foo[10,] and foo[20,]. Seems like this should be possible with an artful call to geom_segment and the grouping variable id?
foo <- data.frame(id = c(1:10,1:10),
samp = rep(c("A","B"),each=10),
x = c(rnorm(10,mean = 5),rnorm(10,mean = 5)),
y = c(rnorm(10,mean = 5),rnorm(10,mean = 6)))
ggplot(foo,aes(x=x,y=y,col=samp)) + geom_point()
Any help appreciated.

We need to use the group as 'id' in the geom_line
library(ggplot2)
ggplot(foo) +
geom_point(aes(x = x,y = y, col = samp)) +
geom_line(aes(x = x, y = y, group = id))
-output

Related

How to return either a vector or string based on condition in ifelse statement?

I am trying to write a function that creates a scatterplot - of which the points may need to be colored based on a variable or not.
I tried the following approach. But it doesn't color the points by group. Although the code runs fine without the ifelse statement.
data <- data.frame(x = rnorm(100,sd=2),
y1 = x*0.5+rnorm(100,sd=1),
y2 = fitted(lm(y~x))) %>%
pivot_longer(cols = -x,
names_to = "Group",
values_to = "yy")
group <- "Group"
ygroups <- 2
defaultcol = "black"
ggplot(data = data, mapping = aes(x = x , y = yy,
color = ifelse(ygroups > 1, get(group), defaultcol))) +
geom_point()
# runs fine
ggplot(data = data, mapping = aes(x = x , y = yy, color = get(group))) +
geom_point()
You don't want to use ifelse in this case because you need to return vectors of different length that your input. Just use a regular if/else
ggplot(data = data) +
aes(x = x , y = yy, color = if(ygroups > 1) get(group) else defaultcol) +
geom_point() +
labs(color="Color")
But you can't set selecific default colors in an aes(color=) -- that will remap the color name via your color scale. If you just want to conditionally add the scale, then do
ggplot(data = data) +
aes(x = x , y = yy) +
{if( ygroups > 1) aes(color=.data[[group]])} +
geom_point()
(using .data[[ ]] is recommended over using get())

ggplot: Drawing tiles / rectangles with discrete variables

I'm attempting to draw tiles / rectangles to get the following result:
library(tidyverse)
library(plotly)
set.seed(0)
df <- tibble(
a = runif(5),
b = runif(5),
c = runif(5),
d = runif(5),
case_id = 1:5
) %>% tidyr::pivot_longer(cols = -case_id)
plot <- ggplot2::ggplot(
data = df,
mapping = aes(
x = name,
y = value,
group = case_id
)
) + geom_point()
plot_boxes_y <- seq(from = 0, to = 1, by = .2)
plot_boxes_x <- unique(df$name) %>% length()
for (x in 1:plot_boxes_x) {
for (y in plot_boxes_y) {
plot <- plot + geom_rect(
mapping = aes_(
xmin = x - .5,
xmax = x + .5,
ymin = y - .5,
ymax = y + .5
),
color = "red",
fill = NA
)
}
}
plotly::ggplotly(plot)
As you can see, I currently do this by looping through coordinates and drawing each rectangle individually. The problem is, that this generates many layers which makes plotly::ggplotly() really slow on large datasets.
Therefore, I'm looking for a more efficient way. Please note, that I cannot use the panel.grid, since I intend to visualize z-data by filling rectangles later on.
My approach was to draw geom_tile() on top of the scatter plot:
# my attempt
df$z <- rep(0, nrow(df))
plot2 <- ggplot2::ggplot(
data = df,
mapping = aes(
x = name,
y = value,
color = z,
group = case_id
)
) + geom_point() + geom_tile()
I assume that this fails because of the fact that name is a discrete variable? So, how can i efficiently draw tiles in addition to my scatterplot?
Thanks
Here is a solution using the geom_tile option. The key here creating a data frame to hold the coordinates of the grid and then specifying the aesthetics individually in each of the function calls.
library(ggplot2)
library(tidyr)
set.seed(0)
df <- tibble(
a = runif(5),
b = runif(5),
c = runif(5),
d = runif(5),
case_id = 1:5
) %>% pivot_longer(cols = -case_id)
df$z <- rep(0, nrow(df))
#make data frame for the grid corrdinates
grid<-data.frame(x=factor( ordered( 1:4), labels = c("a", "b", "c", "d" )),
y=rep(seq(0, 1, .1), each=4))
#plot using geom_tile & geom_point
plot2 <- ggplot2::ggplot() + geom_tile(data=grid, aes(x=x, y=y), fill=NA, col="red") +
geom_point(data = df,
mapping = aes(
x = name,
y = value,
color = z,
group = case_id))
print(plot2)
if you don't mind them going beyond the axis
ggplot(df,aes(x=name,y=value)) + geom_point() +
geom_vline(xintercept=seq(0.5,4.5,by=1)) +
geom_hline(yintercept=seq(0,2,by=.2))
else:
#make a new data frame
GRIDS = rbind(
# the vertical lines
data.frame(x=seq(0.5,4.5,by=1),xend=seq(0.5,4.5,by=1),y=0,yend=2),
# the horizontal lines
data.frame(x=0.5,xend=4.5,y=seq(0,2,by=.2),yend=seq(0,2,by=.2))
)
ggplot(df,aes(x=name,y=value)) + geom_point() +
geom_segment(data=GRIDS,aes(x=x,y=y,xend=xend,yend=yend),col="red")

ggplot change line color specified by x axis values

Code to reproduce:
myDat <- data.frame(Event = rep(c("Arrival", "Departure"), 3),
AtNode = c("StationA", "StationA", "Track", "Track", "StationB", "StationB"),
Lane = c("Lane1", "Lane1", "Lane2", "Lane2", "Lane1", "Lane1"),
atTime = c(10, 12, 18, 20, 34, 36),
Type = c("Station", "Station", "Track", "Track", "Station", "Station"),
Train = 1 )
ggplot(data =myDat, aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))), group = Train, colour = Lane ))+
geom_point(data = myDat)+
geom_path(data = myDat[which(!grepl(pattern = "Track", myDat$Type)),])
Now i need to project the two green points (Y = "Track") on the orange line and color the line between the projected points the same color as the points.
Expected result: (without the points (Y ="Track")
Thanks in advance for every hint or trick!
Cheers
I don't think your output is the right way of showing what you want. You have factors on your y-axis, which means it ranges between 1 and 3.
Therefore, projecting a line there means nothing in terms of y-axis values.
For me, the correct way of showing your data would be like this
ggplot(data =myDat,
aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))),
group = AtNode, colour = Lane ))+
geom_point()+
geom_line() +
labs(y = 'AtNode')
However, to do it how you asked, you can do some simple trigonometry to project your line segment
x1 = 1 + tan(asin(2/sqrt(484)))*6 #y projection given x = 18
x2 = 1 + tan(asin(2/sqrt(484)))*8 #y projection given x = 20
foo = data.frame(x = c(18,20), y = c(x1, x2), Lane = "Lane2")
ggplot(data = myDat, aes(x = atTime, y=factor(AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))), group = 1, colour = Lane ))+
geom_path(data = myDat[which(!grepl(pattern = "Track", myDat$Type)),]) +
geom_line(data = foo, aes(x = x, y = y, color = Lane), size = 1) +
scale_y_discrete(drop = FALSE)
I don't think there is a quick solution to this, but you could do something like this:
myDat$AtNode <- factor(myDat$AtNode, levels = unique(paste(myDat[order(myDat$atTime),"AtNode"]))) #Generate factor here so we can use in imputation calculation
impute_rows <- which(myDat$Type == "Track") #Select rows to impute
slope_df <- myDat[impute_rows + c(-1,1), ] #Select rows before and after imputation to calculate slope
line <- lm(as.numeric(AtNode) ~ atTime, data = slope_df) #Get slope of line so we can do the calculations
df <- data.frame(x = myDat[impute_rows, "atTime"], y = myDat[impute_rows, "atTime"]*line$coefficients[["atTime"]] + line$coefficients[["(Intercept)"]], Lane = myDat[impute_rows,"Lane"], Train = myDat[impute_rows,"Train"])
ggplot(data =myDat, aes(x = atTime, y=AtNode, group = Train, colour = Lane ))+
geom_path(data = myDat[which(!grepl(pattern = "Track", myDat$Type)),]) +
geom_path(data = df, aes(x = x, y = y), size = 2) +
scale_y_discrete(drop = FALSE)
The idea is as follows:
Identify the rows you want to impute: which()
Identify the rows before and after the ones to impute slope_df
Using the rows before and after the desired values to impute generate equation of line you want to impute along (using the slope_df)
Generate data based on the line df <- data.frame(...)
Note that you also need the scale_y_discrete(drop = FALSE) so that the Track level isn't removed from the plot.

Plotting points and lines separately in R with ggplot

I'm trying to plot 2 sets of data points and a single line in R using ggplot.
The issue I'm having is with the legend.
As can be seen in the attached image, the legend applies the lines to all 3 data sets even though only one of them is plotted with a line.
I have melted the data into one long frame, but this still requires me to filter the data sets for each individual call to geom_line() and geom_path().
I want to graph the melted data, plotting a line based on one data set, and points on the remaining two, with a complete legend.
Here is the sample script I wrote to produce the plot:
xseq <- 1:100
x <- rnorm(n = 100, mean = 0.5, sd = 2)
x2 <- rnorm(n = 100, mean = 1, sd = 0.5)
x.lm <- lm(formula = x ~ xseq)
x.fit <- predict(x.lm, newdata = data.frame(xseq = 1:100), type = "response", se.fit = TRUE)
my_data <- data.frame(x = xseq, ypoints = x, ylines = x.fit$fit, ypoints2 = x2)
## Now try and plot it
melted_data <- melt(data = my_data, id.vars = "x")
p <- ggplot(data = melted_data, aes(x = x, y = value, color = variable, shape = variable, linetype = variable)) +
geom_point(data = filter(melted_data, variable == "ypoints")) +
geom_point(data = filter(melted_data, variable == "ypoints2")) +
geom_path(data = filter(melted_data, variable == "ylines"))
pushViewport(viewport(layout = grid.layout(1, 1))) # One on top of the other
print(p, vp = viewport(layout.pos.row = 1, layout.pos.col = 1))
You can set them manually like this:
We set linetype = "solid" for the first item and "blank" for others (no line).
Similarly for first item we set no shape (NA) and for others we will set whatever shape we need (I just put 7 and 8 there for an example). See e.g. http://www.r-bloggers.com/how-to-remember-point-shape-codes-in-r/ to help you to choose correct shapes for your needs.
If you are happy with dots then you can use my_shapes = c(NA,16,16) and scale_shape_manual(...) is not needed.
my_shapes = c(NA,7,8)
ggplot(data = melted_data, aes(x = x, y = value, color=variable, shape=variable )) +
geom_path(data = filter(melted_data, variable == "ylines") ) +
geom_point(data = filter(melted_data, variable %in% c("ypoints", "ypoints2"))) +
scale_colour_manual(values = c("red", "green", "blue"),
guide = guide_legend(override.aes = list(
linetype = c("solid", "blank","blank"),
shape = my_shapes))) +
scale_shape_manual(values = my_shapes)
But I am very curious if there is some more automated way. Hopefully someone can post better answer.
This post relied quite heavily on this answer: ggplot2: Different legend symbols for points and lines

Plot time series and forecast simultaneously using ggplot2

I have a time series with forecast and confidence interval data, I wanted to plot them simultaneously using ggplot2. I'm doing it by the code below:
set.seed(321)
library(ggplot2)
#create some dummy data similar to mine
sample<-rnorm(350)
forecast<-rnorm(24)
upper<-forecast+2*sd(forecast)
lower<-forecast-2*sd(forecast)
## wrap data into a data.frame
df1 = data.frame(time = seq(325,350,length=26), M = sample[325:350], isin = "observations")
df2 = data.frame(time = seq(351,374,length=24), M = forecast , isin = "my_forecast")
df3 = data.frame(time = seq(351,374,length=24), M = upper ,isin = "upper_bound")
df4 = data.frame(time = seq(351,374,length=24), M = lower, isin = "lower_bound")
df = rbind(df1, df2, df3, df4)
## ggplot object
ggplot(df, aes(x = time, y = M, color = isin)) + geom_line()
How can I join upper and lower lines in one color? and also how can I set specific colors to forecast and sample?
Use scale_colour_manual:
ggplot(df, aes(x = time, y = M, color = isin)) + geom_line() +
scale_colour_manual(values=c(observations='blue', my_forecast='red', upper_bound='black', lower_bound='black'))
edit
This is another option, inspired by #rnso answer.
ggplot(df1, aes(x = time, y = M)) + geom_line(colour='blue') +
geom_smooth(aes(x=time, y=M, ymax=upper_bound, ymin=lower_bound),
colour='red', data=df5, stat='identity')
Following may be useful:
ggplot() +
geom_line(data=df1, aes(x = time, y = M, color = isin)) +
stat_smooth(data=df2, aes(x = time, y = M, color = isin))
'method' option can also be used in stat_smooth()

Resources