The misclassification rate is a measure applied in many instances where machine learning needs to differentiate the value of false positive and false negative readings in place of the algorithm’s normal impartial sorting of class type. With regards to efficiency, the misclassification rate of a function can help determine its error rate with regard to how well the interface assesses values inputted from a library and processes them in reference to a list of desired traits that make a value a positive prediction. Classification algorithms faced with a more complex decision tree face a greater chance of producing a classification error, running the risk of giving skewed measurements and inaccurate data representation.
Take this example of a dataset listing traits of a flower species as values for classification:
sapply(dataset, class) – gives us inputs for Species, Petal Dimensions, and Lengths for the classifying rubric.
To find the number of readings for this dataset, we tell the function to find the distributed percentage of instances:
percentage prop.table(table(dataset$Species)) * 100
cbind(freq=table(dataset$Species), percentage=percentage)
then summarize at the end.
When comparing traits of so many values, it’s easy for the function to make a misclassification at this stage of computing, but the way to address this issue depends on what factor you choose to focus on.
For some classifications, the accuracy of misclassification may not make much difference to the final outcome. Computing vital measurements like money waste or total power in a system may need more exacting scrutiny, but for less serious subjects there may be little need to change the coding. In these instances, an accountable misclassification cost is assessed for each class being assigned to the inputs to see which contributes less to the total value calculated by the algorithm so if more errors occur in a particularly relevant class we don’t have to redo the entire system to a great degree if choosing to at all. If in a rare case the confusion matrix of an algorithm is found to have multiple classes covering a wide range of traits, the cost percentage assigned to each value can help streamline a process by identifying unnecessary factors.
In one instance where credit reports are being assessed, the matrix has to deal with varying amounts to place each in a zero or one class. Instead of setting strict thresholds on the qualifiers for classification, the matrix assigns a cost to the values so there’s less occurrence of a major classification error.
With no desire to scrutinize the dataset fully, the function is told to remove two constants:
data(GermanCredit, package = “caret”)
credit.task = makeClassifTask(data = GermanCredit, target = “Class”)
credit.task = removeConstantFeatures(credit.task)
and create a matrix that can file the varying amounts it reads as being of either one or the other class in a simple prediction visual:
costs = matrix(c(0, 1, 5, 0), 2)
colnames(costs) = rownames(costs) = getTaskClassLevels(credit.task)
costs
The use of machine learning for classification cases can be as complex as the programmer makes them out to be. Depending on how much importance you assign the values being inputted, the cost of misclassification can have a huge impact on the accuracy of your results. Using tools to assess and assign value percentages to your dataset can allow you to cut back the error rate of your tool so that when continuing to collect data, you can trust in the relevancy of your outcomes.