confusion

README

Docs: GoDoc

Confusion implements a confusion matrix: records output responses for discrete categories / classes.

• Rows (outer dimension) are for each class as the ground truth, correct answer.

• Columns (inner dimension) are the response generated for each ground-truth class.

The main result is in the Prob field, computed from the Sum and N values added incrementally.

Main API:

• InitFromLabels to initialize with list of class labels and display font size.
• Incr on each trial with network's response index and correct target index.
• Probs when done, to compute probabilities from accumulated data.
• SaveCSV / OpenCSV for saving / loading data (for nogui usage).

The TFPN matrix keeps a record of true/false positives (tp/fp) and true/false negatives (tn/fn) for each category/class. This table is used to calculate F1 scores either by class or across classes

A beginner’s guide on how to calculate Precision, Recall, F1-score for a multi-class classification problem can be found at https://towardsdatascience.com/confusion-matrix-for-your-multi-class-machine-learning-model-ff9aa3bf7826

API:

• SumTFPN to calculate the tp, fp, fn and tn scores for each class
• ScoreClass calculates the precision and recall scores that are needed for the F1 score
• ScoreMatrix uses the values calculated by ScoreClass to generate 3 different F1 scores for the entire matrix
  • F1 Micro
  • F1 Macro
  • F1 Weighted

Documentation

Index

• type Matrix
  • func (cm *Matrix) Incr(class, resp int)
  • func (cm *Matrix) Init(n int)
  • func (cm *Matrix) InitFromLabels(lbls []string, fontSize int)
  • func (cm *Matrix) OpenCSV(fname core.Filename)
  • func (cm *Matrix) Probs()
  • func (cm *Matrix) Reset()
  • func (cm *Matrix) SaveCSV(fname core.Filename)
  • func (cm *Matrix) ScoreClass(class int)
  • func (cm *Matrix) ScoreMatrix()
  • func (cm *Matrix) SetLabels(lbls []string)
  • func (cm *Matrix) SumTFPN(class int)

Types

type Matrix

type Matrix struct {

	// normalized probability of confusion: Row = ground truth class, Col = actual response for that class.
	Prob tensor.Float64 `display:"no-inline"`

	// incremental sums
	Sum tensor.Float64 `display:"no-inline"`

	// counts per ground truth (rows)
	N tensor.Float64 `display:"no-inline"`

	// visualization using SimMat
	Vis simat.SimMat `display:"no-inline"`

	// true pos/neg, false pos/neg for each class, generated from the confusion matrix
	TFPN tensor.Float64 `display:"no-inline"`

	// precision, recall and F1 score by class
	ClassScores tensor.Float64 `display:"no-inline"`

	// micro F1, macro F1 and weighted F1 scores for entire matrix ignoring class
	MatrixScores tensor.Float64 `display:"no-inline"`
}

Matrix computes the confusion matrix, with rows representing the ground truth correct class, and columns representing the actual answer produced. Correct answers are along the diagonal.

func (*Matrix) Incr

func (cm *Matrix) Incr(class, resp int)

Incr increments the data for given class ground truth and response.

func (*Matrix) Init

func (cm *Matrix) Init(n int)

Init initializes the Matrix for given number of classes, and resets the data to zero.

func (*Matrix) InitFromLabels

func (cm *Matrix) InitFromLabels(lbls []string, fontSize int)

InitFromLabels does initialization based on given labels. Calls Init on len(lbls) and SetLabels. Default fontSize = 12 if 0 or -1 passed

func (*Matrix) OpenCSV

func (cm *Matrix) OpenCSV(fname core.Filename)

OpenCSV opens Prob result from a CSV file, comma separated

func (*Matrix) Probs

func (cm *Matrix) Probs()

Probs computes the probabilities based on accumulated data

func (*Matrix) Reset

func (cm *Matrix) Reset()

Reset resets the data to zero

func (*Matrix) SaveCSV

func (cm *Matrix) SaveCSV(fname core.Filename)

SaveCSV saves Prob result to a CSV file, comma separated

func (*Matrix) ScoreClass

func (cm *Matrix) ScoreClass(class int)

func (*Matrix) ScoreMatrix

func (cm *Matrix) ScoreMatrix()

func (*Matrix) SetLabels

func (cm *Matrix) SetLabels(lbls []string)

SetLabels sets the class labels, for visualization in Vis

func (*Matrix) SumTFPN

func (cm *Matrix) SumTFPN(class int)