Loop character values in ggtitle - r

Question

I have a loop of 4 graphs with a character list like 'a, b, c, d', so in the title of each graph I want 'a', 'b', 'c' or 'd'. However, when I run my code, 'a' appears in all titles.
This is the dput of the data I am using.
structure(list(Point = c(5, 6, 7, 8), La = c(535, 565, 532, 587
), Ce = c(45, 46, 58, 43), Pr = c(56, 54, 43, 50), Nd = c(23,
28, 18, 26)), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"
), row.names = c(NA, -4L), spec = structure(list(cols = list(
Point = structure(list(), class = c("collector_double", "collector"
)), La = structure(list(), class = c("collector_double",
"collector")), Ce = structure(list(), class = c("collector_double",
"collector")), Pr = structure(list(), class = c("collector_double",
"collector")), Nd = structure(list(), class = c("collector_double",
"collector"))), default = structure(list(), class = c("collector_guess",
"collector")), skip = 1), class = "col_spec"))
and the code I came up so far. ONLY the cols do not cycle through the title. The rest of the code works perfectly. I am still a beginner, so thank you for your time and patience.
acq <- select(X1, La:Nd)
##loop##
gg <- for (ii in acq){
cols <- names(X1)[2:5]
m <-mean(ii)
sds <- sd(ii)
m1 <- mean(ii)+1
m2 <-mean(ii)-1
##plot##
g <- ggplot(X1,aes_string(x="Point",y="ii")) +
ggtitle(paste(cols,"\n",m,"\n",sds,"\n")) +
theme(plot.title = element_text(hjust = 0.5)) +
geom_line() + geom_hline(aes(yintercept=mean(ii))) + ylab('') + xlab('')+
geom_hline(aes(yintercept=m1),linetype=2) +
geom_text(x=8,y=m1,label="10%",vjust=-1) +
geom_hline(aes(yintercept=m2),linetype=2) +
geom_text(x=8,y=m2,label="10%",vjust=-1)
print(g)
}
My data:
~Point, ~La, ~Ce, ~Pr, ~Nd,
5, 535, 45, 56, 23,
6, 565, 46, 54, 28,
7, 532, 58, 43, 18,
8, 587, 43, 50, 26

Answer 1

They way you setup the for-loop is not really recommended. It's better to loop through column names then extract that column from the acq data frame accordingly
library(tidyverse)
acq <- select(X1, La:Nd)
## loop ##
for (ii in seq_along(colnames(acq))) {
current_col <- colnames(acq)[ii]
print(paste0('Plot col: ', current_col))
# calculate mean and stdev
m <- mean(acq[[current_col]])
sds <- sd(acq[[current_col]])
m1 <- m + 1
m2 <- m - 1
## plot ##
g <- ggplot(X1, aes_string(x = "Point", y = current_col)) +
ggtitle(paste("column = ", current_col, "\n",
"mean = ", formatC(m, digits = 3), "\n",
"sd = ", formatC(sds, digits = 3), "\n")) +
theme_classic(base_size = 12) +
theme(plot.title = element_text(hjust = 0.5)) +
geom_line() +
geom_hline(aes(yintercept = m)) +
ylab("") + xlab("") +
geom_hline(aes(yintercept = m1), linetype = 2) +
geom_text(x = 8, y = m1, label = "10%", vjust = -1, check_overlap = TRUE) +
geom_hline(aes(yintercept = m2), linetype = 2) +
geom_text(x = 8, y = m2, label = "10%", vjust = 2, check_overlap = TRUE)
print(g)
}
Example output:
#> [1] "Plot col: La"
#> [1] "Plot col: Ce"
Another (preferable) way is to use the new tidy evaluation approach (more explanation here)
generate_plot2 <- function(df, .x.variable, .y.variable) {
x.variable <- rlang::sym(.x.variable)
y.variable <- rlang::sym(.y.variable)
sum_df <- df %>%
summarise_at(vars(!!y.variable), funs(mean, sd)) %>%
mutate(m1 = mean + 1,
m2 = mean - 1)
print(sum_df)
g <- ggplot(df, aes(x = !! x.variable, y = !! y.variable)) +
ggtitle(paste("column = ", .y.variable, "\n",
"mean = ", formatC(sum_df$mean, digits = 3), "\n",
"sd = ", formatC(sum_df$sd, digits = 3), "\n")) +
geom_line() +
geom_hline(aes(yintercept = sum_df$mean)) +
ylab("") + xlab("") +
geom_hline(aes(yintercept = sum_df$m1), linetype = 2) +
geom_text(x = 8, y = sum_df$m1, label = "10%", vjust = -1, check_overlap = TRUE) +
geom_hline(aes(yintercept = sum_df$m2), linetype = 2) +
geom_text(x = 8, y = sum_df$m2, label = "10%", vjust = 2, check_overlap = TRUE) +
theme_classic(base_size = 12) +
theme(plot.title = element_text(hjust = 0.5))
return(g)
}
plot_list <- names(X1)[-1] %>%
map(~ generate_plot2(X1, "Point", .x))
#> mean sd m1 m2
#> 1 554.75 26.15817 555.75 553.75
#> mean sd m1 m2
#> 1 48 6.78233 49 47
#> mean sd m1 m2
#> 1 50.75 5.737305 51.75 49.75
#> mean sd m1 m2
#> 1 23.75 4.349329 24.75 22.75
plot_list[[1]]
plot_list[[2]]
# bonus: combine all plots
library(cowplot)
plot_grid(plotlist = plot_list,
labels = 'AUTO',
nrow = 2,
align = 'hv',
axis = 'tblr')
Created on 2019-03-16 by the reprex package (v0.2.1.9000)