सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

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planet to be computed is got by multiplying the planetary
position of a planet computed by the number of sidereal
revolutions of the planet to be computed and dividing by
the number of sidereal revolutions of the planet computed.
Verse 15. We get the Ahargaṇa by multiplying the
planetary position given in number of revolutions and
fraction of a revolution by the number of days in a Kalpa
and dividing by the number of sidereal revolutions in a
Kalpa. How by indeterminate analysis we get the same
Ahargaṇa, given the number of past sidereal revolutions
alone, or by the fractional part of a revolution alone, or
by the sum of the fractional parts in the case of more items
involved, I shall tell later.
Comm. While computing the planet we have the
formula (A × P) / M = p where A = Ahargaṇa, P = the num-
ber of sidereal revolutions of the planet, M = number of
mean solar days in a Kalpa and p = the planetary position
consisting of the number of past revolutions and also the
fraction of a revolution. From the above equation, the
Ahargaṇa A = (M × p) / P as stated. In tne case of only
the integral number of revolutions or the fraction of a
revolution alone being given, or the sum of remainders if
more items than one are involved, the method of fiinding
the Ahargaṇa is illustrated in golādhyāya under praśna-
adhyāya under verses 12—21.
Verses 16, 17. Method of getting the time in solar
years that has elapsed from the beginning of the Kalpa,
given the Ahargaṇa.
The given Ahargaṇa multiplied by the number of
Kshaya-tithis in a Kalpa and divided by the number of
civil days in a Kalpa gives the number of the elapsed Kshaya
tithis. Adding these to the Ahargaṇa we have the lunar