What is an instance in Weka?

What is an instance in Weka?

java.lang.Object | +—-weka.core.Instance public class Instance extends Object implements Copyable, Serializable. Class for handling an instance. All values (numeric, nominal, or string) are internally stored as floating-point numbers.

What is instances in data mining?

These instances are the things that are to be classified, associated, or clustered. Each instance is an individual, independent example of the concept to be learned. The input to a data mining scheme is generally expressed as a table of independent instances of the concept to be learned.

How do I add a instance to Weka?

add(“A”); classVal. add(“B”); atts. add(new Attribute(“content”,(ArrayList)null)); atts. add(new Attribute(“@@class@@”,classVal)); Instances dataRaw = new Instances(“TestInstances”,atts,0);

What is instance in algorithm?

An algorithm is a set of rules for carrying out some calculation. A problem (say sorting a list of numbers) will have many instances. An instance, in this case, can be the list {23,15, 67}. There may be several algorithms to solve the same problem.

What is a concept instance and attribute?

description. ● Instances: the individual, independent examples of a. concept. ◆ note: more complicated forms of input are possible. ● Attributes: measuring aspects of an instance.

What is distinct in weka?

Question: what is the difference between distinct and unique in weka? Answer: Distinct means the number of dissimilar values contained for the selected attribute. Unique means the number and percentage of instances having a value for this attribute that no other instances have in the data.

What is nominal value in weka?

Nominal values are defined by providing an nominal-specification. listing the possible values: {nominal-name1, nominal-name2, nominal-name3.} For example, the class value of the Iris dataset can be defined as follows: @ATTRIBUTE class {Iris-setosa,Iris-versicolor,Iris-virginica}

What is instance based model?

In machine learning, instance-based learning (sometimes called memory-based learning) is a family of learning algorithms that, instead of performing explicit generalization, compare new problem instances with instances seen in training, which have been stored in memory.

What is an instance of a problem?

Definition: An instance of a problem is all the inputs needed to compute a solution to the problem. Definition: A correct algorithm halts with the correct output for every input instance. We can then say that the algorithm solves the problem.

What is weka jitter?

[jitter] is a random displacement applied to X and Y values to separate points that lie on top of one another. Without jitter, 1000 instances at the same data point would look just the same as 1 instance.

What is preprocess in Weka?

1 Preprocess: Preprocessing tools in WEKA are called “Filters”. The Preprocess retrieves data from a file, SQL database or URL (For very large datasets sub sampling may be required since all the data were stored in main memory). Data can be preprocessed using one of Weka’s preprocessing tools.