CS320n – Elements of Visual
Programming
Assignment Help Session
What We Will Do Today
• Illustrate a few key points on the
assignment and work on the assignment
Visual Programming
Assignment Help Session
2
The Assignment
• Simulate rolling two 6 sided dice
• Allow user to input number of times to roll
– numeric control
– this will be input to for loop count terminal
• inside for loop
– need to simulate rolling dice once
– need to count up how many times each result
occurs
– can use an array to do this
Visual Programming
Assignment Help Session
3
Counting Number of Rolls
• One approach
• One way of counting number of times
each value rolled
– store all results in an array
– go through array and count number of 2s,
then number of 3s, then number of 4s…
– A reasonable function would be: how many
elements of an array equal some value, but
there is no LabVIEW function for this
Visual Programming
Assignment Help Session
4
Mapping
• Another approach
• A useful technique in programming
• instead of using an array to hold the
results of the roll, use an array to count the
number of times each roll occurs
• the index of the array is used to map to the
result of a roll
Visual Programming
Assignment Help Session
5
Sample Array
use result of roll as index into array
Index
0
Element 0
1
0
2
1
3
3
4
7
5
8
6
7
12
40
element indicates how many time that roll has occurred. 1 two, 3 threes, 7 fours…
Assume the next roll is a 4. How does array change?
Visual Programming
Assignment Help Session
6
Result is 4
Index
0
Element 0
1
0
2
1
3
3
4
8
5
8
6
7
12
40
Element at index 4 incremented by 1. Was 7, now is 8.
Visual Programming
Assignment Help Session
7
Using Mapping
• To use mapping auto indexing is
not useful when rolling the dice and
counting the results
• Need to use a shift register to pass
whole array between iterations of
the loop
• need to use the Index Array to get
old value of element, increment it
(add 1), and then use the Replace
Array Subset function to update the
element
Visual Programming
Assignment Help Session
8