Plot fitted data from data frame as side-by-side barplot

Question 1

Using base graphics:

# convert the one-row data frame to a two-row matrix
m <- matrix(unlist(df[2, ]), nrow = 2, byrow = TRUE)

# plot
barplot(m, beside = TRUE, col = c("blue", "red"), names.arg = seq_len(ncol(m)))

enter image description here

Possibly add a legend:

legend("topright", legend = c("UT", "TR"), fill = c("blue", "red"))

Question 2

EDIT: Not using reshape per request in comments

library(ggplot2)
plot_data <- data.frame(names(A), t(A[2,]))
names(plot_data) <- c("variable", "value")
plot_data$group <- grepl("^TR", plot_data$variable)
plot_data$variable <- gsub("[^0-9]", "", as.character(plot_data$variable))
plot_data$variable <- factor(plot_data$variable, 
                             unique(sort(as.numeric(plot_data$variable))))
p <- ggplot(aes(y = value, x = variable, fill = group), data = plot_data)
p + geom_bar(stat = "identity", position = "dodge")

Question 3

Here is another option that incorporates your complete dataset. Not sure if this is usefull for you. I've used reshape2, it's actually easier. You just have to melt(yourdataframe), for your particular case there is no need to specify anything else in the melt function arguments.

require("ggplot2")
require("reshape2")

A <- df
df1 <- melt(df[1,])
df1$origen <- "ORDENADA"
df2 <- melt(df[2,])
df2$origen <- "VELOCIDAD"
identical(df1$variable,df2$variable)

df3 <- rbind(df1,df2)
df3$group <- ifelse(grepl("^TR", df3$variable) == TRUE, "TR", "UT")
df3$vble <- gsub("[^0-9]", "", as.character(df3$variable))
df3$vble <- factor(df3$vble, levels = as.numeric(unique(df3$vble)))

ggplot(aes(y = value, x = vble, fill = group), data = df3) +
  geom_bar(stat = "identity", position = "dodge") +
  facet_grid(origen ~ ., scales = "free")

enter image description here

Using Functions

prepare <- function(data){
  data1 <- melt(data[1,])
  data1$origen <- "ORDENADA"
  data2 <- melt(data[2,])
  data2$origen <- "VELOCIDAD"
  identical(data1$variable,data2$variable)
  data3 <- rbind(data1,data2)
  data3$group <- ifelse(grepl("^TR", data3$variable) == TRUE, "TR", "UT")
  data3$vble <- gsub("[^0-9]", "", as.character(data3$variable))
  data3$vble <- factor(data3$vble, levels = as.numeric(unique(data3$vble)))
  return(data3)
}

prepare(df)

#This would work, but is a bit manual for many plots:

ggplot(aes(y = value, x = vble, fill = group), data = prepare(df)) +
      geom_bar(stat = "identity", position = "dodge") +
      facet_grid(origen ~ ., scales = "free")


plot_fun <- function(data){
  p <- ggplot(data, aes_string(x = "vble", y = "value", fill = "group"))
  p <- p + geom_bar(stat = "identity", position = "dodge")
  p <- p + facet_grid(origen ~ ., scales = "free")
  suppressWarnings(print(p))
}

plot_fun(prepare(df))

I guess you could loop in order to plot several data frames using the same plot function. I guess you could probably addapt it more to your needs, but this can get you started