Rockwell Automation 5370-CVIM2 Module - Manual (Page 371)

5 Chapter Chapter 7
Inspection Tools
7–133
The Misc Functions panel lists various additional functions that a math tool
can perform.
After selecting a misc function, you must enter one or more values, as
required for the selected function, followed by a closing parenthesis. At that
point, the entry could operate as a “formula” by itself; however, it would
normally be used as one component of a longer formula.
Here is a brief description of each of the miscellaneous functions:
abs –– The “ abs ” (absolute) function converts a negative number to its
absolute value. For example, the formula “ abs(
*
45) ” will convert
*45 to
45.
dst –– The “ dst ” (distance) function calculates the distance, in pixels, from
one position in the image to another position. It performs this calculation on
the basis of entering the X–axis and Y–axis coordinate values after the
opening parenthesis (and separating them by commas). The
dst function
formula takes the form “ dst(X
1
,Y
1
,X
2
,Y
2
) ,” where X
1
and Y
1
are the
coordinates of one position, and X
2
and Y
2
are the coordinates of the other
position.
The dst function performs the distance computation by using the
Pythagorean theorem: The square of the hypotenuse of a right angle triangle
is equal to the sum of the squares of the two sides.
Thus, to find the distance between two points in the image (the hypotenuse of
a right angle triangle), the
dst function squares the distance along the X–axis
(one side of the triangle) and the Y–axis (the other side of the triangle), then
computes the square root of the sum of the two squares.
For an example of using the dst function to measure a distance in the image,
refer to the Math Tool Formula Examples section on page 7–137.
mod –– The “ mod ” (modulo) function divides the first value entered after
the opening parenthesis by the second value, and it returns the remainder or
“modulo,” if any, resulting from the division operation. The
mod function
formula takes the form “ mod(X
1
,X
2
) ,” where X
1
is the dividend, and X
2
is
the divisor.
For example, the formula “ mod(45,11) ” will divide 45 by 11 (which results
in a quotient of 4 and a remainder of 1) and return a modulo value of 1.000.
sqr –– The “ sqr ” (square) function calculates the square of the value entered
after the opening parenthesis. Thus, the formula “ sqr(25) ” will return a value
of 625.000.