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Master Thesis - Department of Computer Science

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T R<br />

T S<br />

denoted by RVNull and RVNull and are represented as,<br />

RV<br />

RV<br />

T R<br />

Null ≡ {DNull(vx 1 1 ), DNull(vx 1 2 ), . . . , DNull(vx 1 V ), DNull(vx 2 1 ),<br />

. . . , DNull(vx 2 V ), . . . , DNull(vx i j), . . . , DNull(vx C V )} (4.36)<br />

T S<br />

Null ≡ {DNull(tx 1 1 ), DNull(tx 1 2 ), . . . , DNull(tx 1 S ), DNull(tx 2 1 ),<br />

. . . , DNull(tx 2 S), . . . , DNull(tx i j), . . . , DNull(tx C S )} (4.37)<br />

Considering “training response vector set”, RV<br />

T R<br />

Null<br />

, as training as well as testing set,<br />

we calculate an accuracy denoted by A Original<br />

Null , with the condition that same samples<br />

are never compared. So, the calculation <strong>of</strong> A Original<br />

Null<br />

1. For i = 1 to V ∗ C<br />

involves the following steps:<br />

(i) Select a response vector DNull(vxc j ) where i = (c − 1) ∗ V + j from the set<br />

T R RVNull .<br />

(ii) Calculate the Euclidean distance <strong>of</strong> DNull(vx c j) from all other response<br />

T R<br />

vectors in the set RVNull .<br />

(iii) Find the class label <strong>of</strong> the response vector providing minimum distance<br />

from DNull(vx c j) and assign it to DNull(vx c j).<br />

(iv) Cross check the obtained class label with the original label.<br />

2. Calculate A Original<br />

Null<br />

as<br />

Number <strong>of</strong> correctly labeled response vectors<br />

T otal number <strong>of</strong> response vectors<br />

<strong>of</strong> response vectors is V ∗ C in this case.<br />

Then RV<br />

T R<br />

Null<br />

∗100%. Total Number<br />

is used to construct an LDA or nonparametric LDA based eigen-<br />

model. As the length <strong>of</strong> a response vector is equal to the number <strong>of</strong> classes (C) present<br />

in a database, we obtain C eigenvectors in the eigenmodel. Let, the C eigenvectors in<br />

the order <strong>of</strong> decreasing eigenvalues be represented by EVNull = [e 1 Null, ...e i Null, ..., e C Null].<br />

We obtain C eigensubspaces ESV i Null ’s for i = 1, 2..., C where ith eigensubspace<br />

ESV i Null contains first i eigenvectors from the set EVNull. Thus C th eigensubspace,<br />

ESV C Null , is same as EVNull. The performance <strong>of</strong> i th eigensubspace ESV i Null<br />

on “train-<br />

ing response vector set”, which is denoted by A ESV i Null<br />

Null , is evaluated by projecting<br />

RV<br />

T R<br />

Null onto ESV i Null and calculating accuracy in the same manner as described for<br />

the calculation <strong>of</strong> A Original<br />

Null . For each eigensubspace, we compare its performance with<br />

85

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