weisang.com > Documents Articles > ValuesInBursts (FPScript)

ValuesInBursts (FPScript)

21.09.2021

Searches within a data set for values that belong to a burst.

Syntax

ValuesInBursts(DataSet, Threshold, DeltaX [ , Operation = EVENT_DEFAULT ])

 

The syntax of the ValuesInBursts function consists of the following parts:

Part

Description

DataSet

The data set to be searched.

Permitted data structures are data series, data matrix, signal und signal series. All numeric data types are permitted.

For complex data types the absolute value is formed.

If the argument is a list, then the function is executed for each element of the list and the result is also a list.

Threshold

Specifies the threshold value for the burst search. Those values are assigned to a burst, for which at least one of the neighboring values in the interval [-DeltaX, DeltaX] to the left or right lies above the threshold value.

Permitted data structures are scalar value. All numeric data types are permitted. The unit has to be compatible with that of parameter DataSet.

For complex data types the absolute value is formed.

If the argument is a list, then the function is executed for each element of the list and the result is also a list.

DeltaX

Determines the interval [-DeltaX, DeltaX], within which at least one value has to lie above the threshold value in order to assign the value to be examined to the burst.

Permitted data structures are scalar value. All numeric data types are permitted. The unit has to be compatible with that of parameter DataSet.

For complex data types the absolute value is formed.

If the argument is a list, then the function is executed for each element of the list and the result is also a list.

Operation

Specifies the way the function operates.

The argument Operation can have the following values:

Constant

Meaning

EVENT_INDEX

The indices of the values or points meeting the condition are placed in the result data set.

EVENT_EXTRACT

Only the points or values meeting the condition are transferred into the result data set.

EVENT_SETVOID

The points or values that do not meet the condition are also included in the result data set, but there they are marked as void.

EVENT_DEFAULT

Corresponds to EVENT_SETVOID if a data matrix or signal series is present, and otherwise EVENT_INDEX.

+ EVENT_COMPLEMENT

This constant can be optionally added and then reverses the selected operation. Then, for example, for EVENT_EXTRACT, the points that do not meet the condition are copied.

If the argument is a list, then the first element in the list is taken. If this is also a list, then the process is repeated.

If this argument is omitted, it will be set to the default value EVENT_DEFAULT.

Remarks

The DeltaX argument should be as low as possible, but higher than the duration of the period, so that individual waves are not taken to be individual bursts. Not only periodic signals can be analyzed with this function. For example, you can use the function to extract a ramp from a signal. For DeltaX is equal to zero, the function represents a simple threshold value discriminator.

The following illustration shows a signal with two highlighted bursts:

Available in

FlexPro Basic, Professional, Developer Suite

Examples

Arguments s
Dim idx, y, n
idx = IndexNot(ValuesInBursts(s, 0.5, 1., EVENT_INDEX), NumberOfRows(s))
s.y[idx] = 0.
return s
 

This example searches for bursts in a signal and generates a signal in which all values not belonging to bursts are set to zero.

ValuesInBursts({0, 0.1, 0, 0.1, 1.3, 1.2, 1.4, 0.3, 0.1, 0, 0.2}, 0.2, 1)
 

Results in {3L, 4L, 5L, 6L, 7L, 8L}. This example searches for values in a burst and returns the indices. A value belongs to a burst if it or the left or right neighboring value is over 0.2.

See Also

Bursts Function

NextBurst Function

NextValueInBurst Function

Event Isolation Analysis Object

Share article or send as email:

You might be interested in these articles