Predictor Selection MATERIAL AND METHODS

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2.7 Testing

Tests conducted thirty-eight times by using the 100 epoch and varied learning rate. Data testing was done by using Euclidean distance measurement methods.

2.8 Analyzing

This model analyze by calculating the accuracy from the classification of precipitation class. This, shows how appropriated data being classified with the actual class. Calculation accuracy is done by creating a contingency matrix. The Accuracy is calculated by dividing the correct total sample on the diagonal contingency table with the total data equation 5. Accuracy = ∑ diagonal table ∑ x 100 5

3. RESULTS AND DISCUSSIONS

3.1 Correlation

Correlation between average precipitation MJJA with predictor’s IOD, SOI, and SST using correlation analysis. Table 1 shows the correlation analysis using 5 significance level. Table 1 Correlation values r MJJA with IOD, SOI and SST MJJA Month IOD SOI Nino12 Nino3 Nino4 Nino34 average precipitation MJJA May 0.056 0.012 0.110 -0.315 0.061 -0.167 Jun 0.041 -0.414 0.113 -0.225 -0.180 -0.244 Jul -0.126 -0.221 0.235 -0.038 0.130 -0.141 Aug 0.075 0.117 -0.077 0.196 0.021 0.017 Sep 0.137 -0.019 -0.130 0.102 0.038 -0.026 Oct 0.174 -0.126 0.007 0.183 -0.082 0.052 Nov -0.122 0.113 0.168 0.151 -0.077 0.034 Dec -0.196 -0.125 0.146 0.108 -0.134 0.024 Jan 0.399 -0.478 0.414 0.387 0.326 0.305 Feb 0.366 -0.380 0.201 0.500 0.360 0.415 According to Pearson correlation rule table for the amount of 38 years data 8, Pearson value is 0.312. Hence, predictor’s for classification consists of correlation values between r ≥ 0.312 and r ≤ -0.312. This study will use six scenarios to obtain the best model which has high accuracy. On the first scenario we use all of variables. Next Scenario we uses Pearson value rule. On the third scenario we choose the highest correlation each variable, and the others we use principal component analysis method. The complete scenario’s shown at Table 2. Table 2 Scenario Scenario Predictor 1 IOD, SOI, Nino3 and Nino4 2 IOD-Jan, IOD-Feb, SOI-Jun, SOI-Jan, SOI-Feb, Nino12-Jan, Nino3-May, Nino3- Jan, Nino3-Feb, Nino4-Jan, Nino4-Feb and Nino34-Feb 3 SOI-Jun, SOI-Jan, Nino12-Jan, Nino3-Feb, Nino34-Feb 4 PC1, PC2 and PC3 5 PC1, PC2, PC3, PC4 and PC5 6 PC1, PC2, PC3, PC4, PC5, PC6 and PC7

3.2 Modeling LVQ

LVQ method produced accuracy for each scenario with small differences to classify precipitation on dry season, shown at Figure 2. The first, third, fourth and sixth scenarios produce the level of accuracy 71.05 with learning rate of 0.002, 0.004 and 0.005 are highest than second