# Math

Allows you to perform basic math operations on one, two, or three curves at a time.

The operations include curve addition and multiplication and resultants, for example. The start, end, or sample frequency of the various curves is not an issue - the VST automatically crops and samples the input curves as needed. The curves must be using the same units, in most cases.

The Math menu contains three secondary menus: one curve, two curves, and three curves. Those secondary menus contain the following plot macros:

## One Curve

Absolute
Given c1, a curve is created which is the absolute value of y vs. x.
Acoustic Weighting
Auto Correlation
If you are comparing two curves, this function would show where the curves match in phase, where c1 and c2 are the same curve.
Auto correlation between two curves.
Output
• x: lag
• y: correlation (A value of 1 is a perfect correlation)
This can be read as: At a lag of time "x", c1 and c2 have a correlation value of "y".
Derivative
Given c1, a curve is created that is the derivative of c1.
Double Integral
Given c1, a curve is created that is the double integral of c1.
Double Derivative
Duration
Calculates the load versus duration for a given curve.
Duration Comp
Partitions the input curve into 101 bins, reporting only the negative curve values.
Duration Tens
Partitions the input curve into 101 bins, reporting only on the positive curve values.
Integral
Given c1, calculates the integral of the c1.
Max Note
Min Note
Normalize
Given c1, calculates a new curve, such that the peak value is "1".
Normalize over Max
Resample or Sample Points
Resamples the given input curve to the specified data frequency.
Reverse Curve
Reverses a curve about the vertical axis, like a mirror.
Square
Calculates the square of the curve.
Window
Crops the curve to the given window size.
Window Integral
Given c1, calculates the integral of c1 over the range of the window.
Zero
Sets the y value in a given range to the user-defined constant.
g>>mph
Integrates acceleration curve to obtain velocity.
Input: g’s vs. seconds
Output: mph vs. seconds
g>>inch
Double integrates an acceleration curve (given in g’s and seconds) to a displacement (given in inches and seconds).
mph>>g
Given c1, a curve is created that is the derivative of velocity to acceleration, while converting MPH to g's.

## Two Curves

Average
Averages two curves.
Cross Correlation
Given c1 and c2, a curve is created which is the cross correlation between the y vectors of c1 and c2.
Cross correlation between two curves.
Output ➔➔
x: lag
y: correlation (A value of 1 is a perfect correlation)
This can be read as: At a lag of time "x", c1 and c2 have a correlation value of "y".
Cross Plot
Given c1 and c2, this function plots c1.y as x and c2.y as y of a new curve.
Divide
Divides two curves. If c2 has zero values, this will fail.
Divide with Zero
If c1 is divided by c2, and if c2 has any zero values, then c1/c2 equals 0.
Multiply
Multiplies two curves.
Resultant
Given c1 and c2, calculates the square root of (c12 + c22).
Subtract
Subtracts two curves.