Research Article
Parameter Estimation for Type III Discrete Weibull Distribution: A Comparative Study
Table 2
Simulation results: bias (
B) and root mean square error (RMSE) for the estimators of
and
.
| | P | ML | M | | P | ML | M | B | RMSE | B | RMSE | B | RMSE | B | RMSE | B | RMSE | B | RMSE |
| | 0.1 | 0.001 | 0.032 | 0.000 | 0.024 | 0.001 | 0.025 | 1 | 0.033 | 0.636 | 0.028 | 0.181 | 0.020 | 0.183 | 0.1 | 0.001 | 0.032 | 0.000 | 0.024 | 0.001 | 0.025 | 0.75 | 0.025 | 0.658 | 0.025 | 0.162 | 0.017 | 0.165 | 0.1 | 0.001 | 0.032 | 0.000 | 0.023 | 0.001 | 0.024 | 0.50 | 0.014 | 0.683 | 0.022 | 0.143 | 0.017 | 0.145 | 0.1 | 0.001 | 0.032 | 0.000 | 0.022 | 0.000 | 0.023 | 0.25 | −0.001 | 0.718 | 0.019 | 0.124 | 0.019 | 0.127 |
| 0.2 | 0.001 | 0.048 | 0.000 | 0.040 | 0.000 | 0.040 | 0.75 | 0.009 | 0.475 | 0.029 | 0.179 | 0.029 | 0.177 | 0.2 | 0.001 | 0.048 | 0.000 | 0.039 | −0.001 | 0.039 | 0.5 | 0.003 | 0.494 | 0.025 | 0.158 | 0.027 | 0.158 | 0.2 | 0.001 | 0.048 | 0.000 | 0.038 | −0.002 | 0.038 | 0.25 | −0.003 | 0.512 | 0.022 | 0.140 | 0.029 | 0.143 | 0.2 | 0.001 | 0.048 | 0.000 | 0.037 | −0.003 | 0.038 | 0 | −0.008 | 0.537 | 0.019 | 0.120 | 0.031 | 0.128 |
| 0.4 | 0.003 | 0.072 | 0.000 | 0.065 | −0.001 | 0.065 | 0.5 | 0.000 | 0.377 | 0.030 | 0.187 | 0.033 | 0.186 | 0.4 | 0.003 | 0.072 | 0.000 | 0.064 | −0.002 | 0.064 | 0.25 | −0.004 | 0.395 | 0.027 | 0.167 | 0.035 | 0.168 | 0.4 | 0.003 | 0.072 | 0.000 | 0.063 | −0.005 | 0.063 | 0 | −0.010 | 0.412 | 0.025 | 0.147 | 0.038 | 0.152 | 0.4 | 0.003 | 0.072 | −0.001 | 0.062 | −0.010 | 0.064 | −0.25 | −0.017 | 0.430 | 0.023 | 0.127 | 0.047 | 0.139 |
| 0.6 | 0.004 | 0.093 | 0.000 | 0.087 | −0.002 | 0.086 | 0.25 | 0.004 | 0.359 | 0.036 | 0.195 | 0.043 | 0.195 | 0.6 | 0.004 | 0.093 | 0.000 | 0.086 | −0.005 | 0.086 | 0 | −0.001 | 0.371 | 0.032 | 0.175 | 0.046 | 0.178 | 0.6 | 0.004 | 0.093 | −0.001 | 0.085 | −0.011 | 0.085 | −0.25 | −0.007 | 0.386 | 0.030 | 0.154 | 0.055 | 0.163 | 0.6 | 0.004 | 0.093 | −0.001 | 0.083 | −0.029 | 0.088 | −0.5 | −0.013 | 0.406 | 0.028 | 0.131 | 0.077 | 0.152 |
| 0.8 | 0.006 | 0.111 | 0.001 | 0.106 | −0.005 | 0.105 | 0 | −0.001 | 0.363 | 0.040 | 0.204 | 0.056 | 0.204 | 0.8 | 0.006 | 0.111 | 0.001 | 0.105 | −0.011 | 0.105 | −0.25 | −0.005 | 0.379 | 0.038 | 0.182 | 0.064 | 0.188 | 0.8 | 0.006 | 0.111 | 0.000 | 0.104 | −0.027 | 0.106 | −0.5 | −0.009 | 0.397 | 0.035 | 0.159 | 0.085 | 0.175 |
| 0.9 | 0.008 | 0.123 | 0.001 | 0.116 | −0.027 | 0.116 | −0.5 | −0.012 | 0.398 | 0.040 | 0.176 | 0.091 | 0.188 |
| | 0.1 | 0.001 | 0.046 | 0.000 | 0.034 | 0.001 | 0.034 | 1 | 0.061 | 0.943 | 0.059 | 0.269 | 0.046 | 0.261 | 0.1 | 0.001 | 0.046 | −0.001 | 0.033 | 0.001 | 0.033 | 0.75 | 0.040 | 0.978 | 0.053 | 0.240 | 0.045 | 0.236 | 0.1 | 0.001 | 0.046 | −0.001 | 0.032 | 0.000 | 0.032 | 0.50 | 0.021 | 1.012 | 0.047 | 0.211 | 0.042 | 0.208 | 0.1 | 0.001 | 0.046 | −0.001 | 0.031 | −0.001 | 0.031 | 0.25 | 0.005 | 1.047 | 0.040 | 0.182 | 0.043 | 0.181 |
| 0.2 | 0.002 | 0.067 | −0.001 | 0.055 | −0.002 | 0.055 | 0.75 | 0.013 | 0.703 | 0.059 | 0.262 | 0.060 | 0.258 | 0.2 | 0.002 | 0.067 | −0.001 | 0.054 | −0.002 | 0.054 | 0.5 | 0.003 | 0.732 | 0.052 | 0.232 | 0.057 | 0.231 | 0.2 | 0.002 | 0.067 | −0.002 | 0.053 | −0.004 | 0.053 | 0.25 | −0.014 | 0.761 | 0.047 | 0.205 | 0.059 | 0.209 | 0.2 | 0.002 | 0.067 | −0.002 | 0.052 | −0.007 | 0.052 | 0 | −0.026 | 0.801 | 0.041 | 0.176 | 0.063 | 0.186 |
| 0.4 | 0.005 | 0.100 | −0.002 | 0.091 | −0.004 | 0.090 | 0.5 | 0.005 | 0.537 | 0.065 | 0.278 | 0.071 | 0.274 | 0.4 | 0.005 | 0.100 | −0.002 | 0.089 | 0.072 | 0.088 | 0.25 | −0.004 | 0.562 | 0.058 | 0.247 | 0.072 | 0.247 | 0.4 | 0.005 | 0.100 | −0.002 | 0.088 | −0.011 | 0.086 | 0 | −0.014 | 0.588 | 0.053 | 0.218 | 0.078 | 0.223 | 0.4 | 0.005 | 0.100 | −0.003 | 0.086 | −0.020 | 0.086 | −0.25 | −0.027 | 0.626 | 0.048 | 0.189 | 0.091 | 0.203 |
| 0.6 | 0.007 | 0.131 | −0.002 | 0.123 | −0.006 | 0.120 | 0.25 | 0.005 | 0.518 | 0.074 | 0.291 | 0.089 | 0.287 | 0.6 | 0.007 | 0.131 | −0.002 | 0.122 | −0.011 | 0.119 | 0 | −0.005 | 0.542 | 0.068 | 0.262 | 0.094 | 0.263 | 0.6 | 0.007 | 0.131 | −0.003 | 0.120 | −0.022 | 0.117 | −0.25 | −0.016 | 0.564 | 0.063 | 0.231 | 0.107 | 0.240 | 0.6 | 0.007 | 0.131 | −0.004 | 0.117 | −0.047 | 0.119 | −0.5 | −0.025 | 0.594 | 0.058 | 0.199 | 0.136 | 0.225 |
| 0.8 | 0.012 | 0.158 | 0.000 | 0.151 | −0.010 | 0.147 | 0 | −0.009 | 0.534 | 0.085 | 0.309 | 0.114 | 0.306 | 0.8 | 0.012 | 0.158 | −0.001 | 0.149 | −0.021 | 0.145 | −0.25 | −0.018 | 0.556 | 0.079 | 0.278 | 0.127 | 0.282 | 0.8 | 0.012 | 0.158 | −0.002 | 0.147 | −0.045 | 0.145 | −0.5 | −0.029 | 0.586 | 0.075 | 0.245 | 0.154 | 0.264 |
| 0.9 | 0.014 | 0.175 | −0.002 | 0.165 | −0.045 | 0.160 | −0.5 | −0.029 | 0.590 | 0.086 | 0.273 | 0.167 | 0.288 |
| | 0.1 | 0.004 | 0.075 | 0.000 | 0.055 | 0.002 | 0.054 | 1 | −0.156 | 1.154 | 0.145 | 0.472 | 0.122 | 0.443 | 0.1 | 0.004 | 0.075 | 0.000 | 0.054 | 0.001 | 0.052 | 0.75 | −0.125 | 1.139 | 0.129 | 0.421 | 0.111 | 0.388 | 0.1 | 0.004 | 0.075 | 0.000 | 0.053 | 0.000 | 0.050 | 0.50 | −0.082 | 1.128 | 0.113 | 0.368 | 0.105 | 0.336 | 0.1 | 0.004 | 0.075 | 0.000 | 0.051 | −0.003 | 0.047 | 0.25 | −0.013 | 1.103 | 0.098 | 0.317 | 0.105 | 0.292 |
| 0.2 | 0.008 | 0.110 | −0.001 | 0.090 | −0.002 | 0.087 | 0.75 | 0.011 | 1.126 | 0.141 | 0.455 | 0.143 | 0.441 | 0.2 | 0.008 | 0.110 | −0.001 | 0.088 | −0.004 | 0.084 | 0.5 | 0.006 | 1.153 | 0.124 | 0.402 | 0.136 | 0.389 | 0.2 | 0.008 | 0.110 | −0.001 | 0.086 | −0.008 | 0.081 | 0.25 | 0.005 | 1.165 | 0.110 | 0.354 | 0.135 | 0.346 | 0.2 | 0.008 | 0.110 | −0.002 | 0.084 | −0.014 | 0.077 | 0 | 0.027 | 1.163 | 0.097 | 0.304 | 0.141 | 0.306 |
| 0.4 | 0.013 | 0.163 | −0.002 | 0.147 | −0.006 | 0.142 | 0.5 | 0.004 | 0.912 | 0.156 | 0.476 | 0.170 | 0.462 | 0.4 | 0.013 | 0.163 | −0.002 | 0.145 | −0.012 | 0.138 | 0.25 | −0.018 | 0.948 | 0.140 | 0.426 | 0.169 | 0.416 | 0.4 | 0.013 | 0.163 | −0.003 | 0.142 | −0.021 | 0.133 | 0 | −0.040 | 0.979 | 0.129 | 0.378 | 0.177 | 0.375 | 0.4 | 0.013 | 0.163 | −0.004 | 0.139 | −0.035 | 0.128 | −0.25 | −0.038 | 0.992 | 0.115 | 0.328 | 0.192 | 0.340 |
| 0.6 | 0.023 | 0.216 | 0.001 | 0.199 | −0.010 | 0.189 | 0.25 | −0.017 | 0.883 | 0.171 | 0.499 | 0.202 | 0.482 | 0.6 | 0.023 | 0.214 | −0.001 | 0.196 | −0.020 | 0.184 | 0 | −0.043 | 0.922 | 0.163 | 0.458 | 0.214 | 0.447 | 0.6 | 0.023 | 0.216 | −0.002 | 0.193 | −0.037 | 0.179 | −0.25 | −0.056 | 0.949 | 0.149 | 0.405 | 0.228 | 0.407 | 0.6 | 0.023 | 0.216 | −0.004 | 0.190 | −0.072 | 0.179 | −0.5 | −0.063 | 0.972 | 0.138 | 0.354 | 0.263 | 0.383 |
| 0.8 | 0.031 | 0.265 | 0.002 | 0.247 | −0.019 | 0.233 | 0 | −0.025 | 0.885 | 0.199 | 0.534 | 0.252 | 0.517 | 0.8 | 0.031 | 0.265 | 0.001 | 0.244 | −0.036 | 0.227 | −0.25 | −0.035 | 0.905 | 0.191 | 0.494 | 0.274 | 0.487 | 0.8 | 0.031 | 0.265 | −0.002 | 0.241 | −0.069 | 0.225 | −0.5 | −0.052 | 0.935 | 0.182 | 0.443 | 0.306 | 0.459 |
| 0.9 | 0.038 | 0.292 | 0.000 | 0.267 | −0.068 | 0.250 | −0.5 | −0.029 | 0.914 | 0.205 | 0.492 | 0.331 | 0.502 |
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P: method of proportion, M: method of moments, and ML: maximum likelihood method.
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