Description
Arrays and Multi-dimensioned Arrays
You are to develop a program that will analyze a set of elevation data collected in a text file. The text
file is formatted as a series of rows and columns. The first row will contain two values that are the
number of rows of data followed by the number of columns. All the values in the data file are integer
values in the range of 15000 to 99000 inclusive. However, the range of data could be smaller than the
absolute range. See the Assignment#1 folder for a copy of the data file called ELEVATIONS.TXT.
The first row in the data file contains three numbers:
1) Number of Rows, 2) Number of Columns, 3) Exclusion Radius.
The data starts at line 2 of the data file and each value is separated with a space.
Requirements
You must determine the following about the data set:
1. Print the lowest elevation value and the number of times it is found in the complete data set.
0 1 2 3 4 5
0 21 33 44 12 59 32
1 12 11 10 18 19 21
2 10 44 99 12 13 10
3 96 44 55 12 10 67
4 23 33 12 33 10 65
5 32 12 77 99 73 43
You will notice that 10 is the lowest value in the data set and it occurs 5 times.
2. Print all the local peaks where the peak elevation is greater or equal to 98480 with a value for n
(index radius) of 11. A local peak occurs when a value is higher than all the values within n
rows and columns inclusive in all directions of the data set. Local peaks in the first n rows, first
n columns, last n rows and last n columns can be excluded from the analysis. The example
below is a 10 x 10 data set where the index radius (n) is set to 2 and where we are interested in
all local peaks between 90 and 99 inclusive:
0 1 2 3 4 5 6 7 8 9
0 21 33 44 12 59 32 77 66 44 11
1 12 11 10 18 19 21 61 23 95 14
2 10 44 99 12 13 10 55 44 41 65
3 96 44 55 12 10 67 23 32 65 43
4 23 33 12 33 10 65 87 66 53 91
5 32 12 77 98 73 43 33 12 42 23
6 37 62 27 43 61 11 12 91 33 12
7 76 19 43 57 64 77 81 73 43 29
8 18 21 37 98 19 71 44 83 11 42
9 12 42 77 75 73 88 13 22 52 28
There are 2 local peaks which occur are 99(2,2) and 98(5,3). Note that although 95, 96 and 98
are examples of local peaks they occur in the excluded area (first and last 2 rows, first and last
2 columns). Also note that the two values of 91 are not considered local peaks as they are the
same height and are too close together (within the exclusion radius) – they cancel each other
out (must be greater not equal.
3. Print the row and column of the two closest local peaks using the formula for distance
presented below:
𝑑
2 = (𝑟1 − 𝑟2)
2 + (𝑐1 − 𝑐2)
2
where d is the distance
r1,r2 are the row numbers of the two peaks
c1,c2 are the column numbers of the two peaks
In the data presented above the min distance would be 3.16 (the two peaks located at (2,2 with
an elevation of 99) and (5,3 with an elevation of 98). Print the distance between the two peaks
to 2-decimal places.
Challenge: There may be more than one set of closest peaks – can you find out how many and
print all of them.
4. Print the most common elevation in the data set. In the data set presented above the most
common value is 12 and it occurs 10 times.
Your solution must read all the data into a two-dimensional array and then close the file. Each of the 4
parts above MUST be solved by writing a single method (1 for each part) that is passed the twodimensional array and any other input you desire. The method may return data of any type (returning
arrays can be quite useful here). Also note that if you save all the Peaks in Part 2, you can use this data
for Part 3. You may wish to create a class to store the Peaks.
Your solution must use only arrays and multi-dimensioned arrays. No array lists or other data
structures are allowed for this problem.
Marking Scheme
Program Structure – Implemented using best practices and arrays only / commented – 35%
All options implemented, complete and correct – 50%
Efficiency (completes in less than 2 seconds) – 15%