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Artificial Intelligence - R Programming Advanced

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Lesson Description


Lession - #932 R Bars


Bar Charts
A bar chart uses rectangular bars to visualize data. Bar charts can be displayed horizontally or vertically. The height or length of the bars are proportional to the values they represent.
Use the
barplot(>
function to draw a vertical bar chart:
Example
# x-axis values
x <- c("A", "B", "C", "D">


# y-axis values
y <- c(2, 4, 6, 8>


barplot(y, names.arg = x>
Result:
Example Explained
  • The
    x
    variable represents values in the x-axis (A,B,C,D>
  • The
    y
    variable represents values in the y-axis (2,4,6,8>
  • Then we use the
    barplot(>
    function to create a bar chart of the values
  • names.arg
    defines the names of each observation in the x-axis

Bar Color
Use the
col
parameter to change the color of the bars:
Example
x <- c("A", "B", "C", "D">

y <- c(2, 4, 6, 8>


barplot(y, names.arg = x, col = "red">
Result:

Density / Bar Texture
To change the bar texture, use the
density
parameter:
Example
x <- c("A", "B", "C", "D">

y <- c(2, 4, 6, 8>


barplot(y, names.arg = x, density = 10>
Result:


Bar Width
Use the
width
parameter to change the width of the bars:
Example
x <- c("A", "B", "C", "D">

y <- c(2, 4, 6, 8>


barplot(y, names.arg = x, width = c(1,2,3,4>
>
Result:

Horizontal Bars
If you want the bars to be displayed horizontally instead of vertically, use
horiz=TRUE
:
Example
x <- c("A", "B", "C", "D">

y <- c(2, 4, 6, 8>


barplot(y, names.arg = x, horiz = TRUE>
Result: