eventStreamImportOptions

Create options for importing events from stream into MATLAB

Since R2022b

This function requires Streaming Data Framework for MATLAB^® Production Server™.

Syntax

opts = eventStreamImportOptions(VariableNames=names,VariableTypes=types)

opts = eventStreamImportOptions(KeyVariable=kv)

opts = eventStreamImportOptions(VariableNames=names,VariableTypes=types,KeyVariable=kv)

Description

Use eventStreamImportOptions only when you are unable to detect import options from the stream object using detectImportOptions.

opts = eventStreamImportOptions(VariableNames=names,VariableTypes=types) sets the VariableNames and VariableTypes properties of the ImportOptions object opts. names and types are the names and data types of event variables that you want to import from an event stream into MATLAB.

opts = eventStreamImportOptions(KeyVariable=kv) sets the KeyVariable property of the ImportOptions object opts.

opts = eventStreamImportOptions(VariableNames=names,VariableTypes=types,KeyVariable=kv) sets the VariableNames, VariableTypes, andKeyVariable properties.

Examples

Create Variable Import Options for Event Stream Data

Create a schema for importing data from an event stream into MATLAB by specifying variable names and their data types to use during the import.

names = ["x","symbol"];
types = ["double","string"];

Construct an ImportOptions object using this data import schema.

opts = eventStreamImportOptions(VariableNames=names,VariableTypes=types)

opts = 

  ImportOptions with properties:

            VariableNames: ["x"    "symbol"]
            VariableTypes: ["double"    "string"]
              KeyVariable: [0×0 string]
    SelectedVariableNames: ["x"    "symbol"]

Apply the import options when creating a KafkaStream object.

ks = kafkaStream("kafka.host.com",9092,"Your_Kafka_Topic",ImportOptions=opts);

Import the data. The "Your_Kafka_Topic" topic must have events with exactly two variables, x and symbol. In addition, the types of these variables must be convertible to double and string, respectively. Otherwise, readtimetable throws an error.

tt = readtimetable(ks);

Input Arguments

names — Variable names

string scalar | string array | cell array of character vectors

Variable names to use when importing variables from the event stream into a timetable, specified as a string scalar, string array, or cell array of character vectors.

Data Types: string | cell

types — Data type of variables

string scalar | string array | cell array of character vectors

Data type of variables to use when importing variables from the event stream into a timetable, specified as a string scalar, string array, or cell array of character vectors containing a set of valid data type names. The VariableTypes property designates the data types.

Data Types: string | cell

kv — Event key variable name

string scalar | character vector

Event key variable name to use when importing variables from the event stream into a timetable, specified as a string scalar or character vector.

Data Types: string | char

Version History

Introduced in R2022b