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Experimental Time Evaluations

The following tables (Tab.13,Tab.14,Tab.15) are of great importance.

Tab.13 is the same as Tab.5 (with "Reduced value y(1)" and "ORD") but brings time evaluation of the computation. For instance, using the 17th method order requires 0.983 ms.


Reduced value y(1) ORD Time (ms)
2. 1 0.084
2. 2 0.140
2. 3 0.195
2.7 4 0.248
2.71 5 0.307
2.718 6 0.365
2.7182 7 0.422
2.7182 8 0.468
2.718281 9 0.531
2.7182818 10 0.589
2.71828182 11 0.649
2.718281828 12 0.693
2.7182818284 13 0.757
2.71828182845 14 0.828
2.71828182845 15 0.861
2.71828182845904 16 0.911
2.71828182845904 17 0.983
2.71828182845904 18 1.033




Tab.13

If we wanted to reach the same accuracy by the 4th order Runge-Kutta method, we would have to use a substantially shorter integration step and the computation time would be 271.229 ms ( Tab.14).


h(s) Reduced value y(1) Time (ms)
1 2.7 0.299
0.1 2.7182 2.691
0.01 2.718281828 27.500
0.001 2.71828182845904 271.229




Tab.14

Tab.15 shows that it is possible to calculate the differential equation (20) with the integration step as great as 400s, which requires the use of 575 Taylor series terms. The computation takes 31.999 ms.


h(s) ORD Time (ms)
1 18 1.033
10 43 2.504
20 64 3.560
30 82 4.642
40 99 5.551
50 115 6.487
100 200 11.282
400 575 31.999




Tab.15

Note: All time evaluations were obtained on the ACA 32000 computer (based on National Semiconductor 32000 processor).


next up previous contents
Next: Homogenous Equation - Example Up: Homogenous Equation - Example Previous: Evaluation of the Computation