Difference
Advanced Analysis Library Only
AnalysisLibErrType Difference (double inputArray[], ssize_t numberOfElements, double samplingInterval, double initialCondition, double finalCondition, double outputArray[]);
Purpose
 |
Note This function has been superseded by DifferenceEx. |
Finds the discrete difference of the input array. Difference obtains the 
element of the resulting array using the following formula:
| where | X–1 is the initial condition |
| Xn is the final condition |
Difference can perform the operation in place; that is, the input and output arrays can be the same.
Example
/* Generate an array with random numbers and differentiate it. */
double x[200], y[200];
double dt, xInit, xFinal;
int n;
n = 200;
dt = 0.001;
xInit = -0.5;
xFinal = -0.25;
Uniform (n, 17, x);
Difference (x, n, dt, xInit, xFinal, y);
Parameters
| Input | ||
| Name | Type | Description |
| inputArray | double [] | Input array to differentiate. |
| numberOfElements | ssize_t | Number of elements to include in the differentiation. |
| samplingInterval | double | Sampling interval used in the differentiation of the input array. Default Value: 1.0. |
| initialCondition | double | Initial condition. When the differentiation formula is applied to each array element, the value of the preceding array element is used. initialCondition specifies the value preceding the first element of the input array. In other words, initialCondition can be thought of as the value of X–1. Default Value: 0.0. |
| finalCondition | double | Final condition. When the differentiation formula is applied to each array element, the value of the next array element is used. finalCondition specifies the value following the last element of the input array. In other words, finalCondition can be thought of as the value of Xn. Default Value: 0.0. |
| Output | ||
| Name | Type | Description |
| outputArray | double [] | Differentiated array. |
Return Value
| Name | Type | Description |
| status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants. |
Additional Information
Library: Advanced Analysis Library
Include file: analysis.h
LabWindows/CVI compatibility: LabWindows/CVI 3.1 and later