Question

7. There are two parts to this question; do part (b) first. (a) [1 mark] Write the function barchart :: Int -> [(String, Int) -> String, that takes a width specifier (say \textit{w}), and a list of (label, value) pairs and draws a horizontal bar chart. For example barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz", 3)] => "xxxx *\nyyy **\nzzzzzz \n" or using putStr for nicer display: putStr $ barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz",3)] => xxxx yyy ** zzzzzz * (b) [1 mark] To implement barchart, first write the simpler function: bar :: Int -> (String, Int) -> String that creates just a single line of the bar chart. One '*' character is drawn for each value, and the label is shown padded out to \textit{w} characters wide or truncated to \textit{w} characters wide. Then barchart can be written in terms of bar, map and unlines. Note: unlines :: [String] -> String is a standard prelude function that takes a list of strings and joins them together (similar to concat) after adding a newline character to the end of each string. The result is a single string that displays as a sequence of lines.

          7. There are two parts to this question; do part (b) first.
(a) [1 mark] Write the function barchart :: Int -> [(String, Int) -> String,
that takes a width specifier (say \textit{w}), and a list of (label, value) pairs and draws a
horizontal bar chart.
For example
barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz", 3)] =>
"xxxx *****\nyyy ********\nzzzzzz ***\n"
or using putStr for nicer display:
putStr $ barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz",3)] =>
xxxx
*****
yyy
********
zzzzzz
***
(b) [1 mark] To implement barchart, first write the simpler function:
bar :: Int -> (String, Int) -> String that creates just a single line of the bar
chart. One '*' character is drawn for each value, and the label is shown padded out to
\textit{w} characters wide or truncated to \textit{w} characters wide. Then barchart can be written
in terms of bar, map and unlines.
Note: unlines :: [String] -> String is a standard prelude function that takes
a list of strings and joins them together (similar to concat) after adding a newline
character to the end of each string. The result is a single string that displays as a
sequence of lines.

7. There are two parts to this question; do part (b) first.
(a) [1 mark] Write the function barchart :: Int -> [(String, Int) -> String,
that takes a width specifier (say w), and a list of (label, value) pairs and draws a
horizontal bar chart.
For example
barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz", 3)] =>
"xxxx ****************"
or using putStr for nicer display:
putStr barchart 5 [("xxxx", 5), ("yyy",8), ("zzzzzzzz",3)] =>
xxxx
*****
yyy
********
zzzzzz
***
(b) [1 mark] To implement barchart, first write the simpler function:
bar :: Int -> (String, Int) -> String that creates just a single line of the bar
chart. One '*' character is drawn for each value, and the label is shown padded out to
w characters wide or truncated to w characters wide. Then barchart can be written
in terms of bar, map and unlines.
Note: unlines :: [String] -> String is a standard prelude function that takes
a list of strings and joins them together (similar to concat) after adding a newline
character to the end of each string. The result is a single string that displays as a
sequence of lines.

Added by Virginia G.

Question

Please give Ace some feedback