e m is a posterior mean vector and is defined as below,
ܕൌߚሺߚ܆܆௧ߙ۷ሻିଵ܆ܡ
(3.26)
uation and generalisation of a supervised machine learning
nant analysis or classification analysis belong to the supervised
learning category. A critical issue of a supervised machine
model is whether it has been properly evaluated before being
for real use, i.e., for the inference on new data. There are mainly
oaches for evaluating a discriminant analysis model. They are the
n matrix for the fix-point evaluation and the receiver operating
istic analysis for the robustness evaluation. The other issue in
hip with a supervised machine learning model is whether the
nce of the model has been well tested using a novel data set. This
s called the generalisation test of a supervised machine learning
his section will address these two practical issues.
nfusion matrix
ion matrix is a fix-point evaluation approach [Stehman, 1997].
uts of most discriminant models are continuous. Therefore, a
is required to convert the continuous model output variable (ݕො)
ry prediction class variable. Suppose a threshold (ߜ) has been
ݕො൏ߜ will lead to one class label such as zero and ݕොߜ will
her class label such as one.
a discriminant model has been constructed and predictions have
de, an output (prediction) table will be received as shown in Table
pose a threshold has been decided. The prediction variable ݕො is
d to the prediction label variable Z. It is also supposed that the
omposed of two classes of data points, which are labelled by A
ble 3.2 shows such a prediction table, in which two columns were