User talk:Retroburrowers: Difference between revisions

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Please check [[//rosettacode.org/wiki/Category:ZX_Spectrum_Basic ZX Spectrum page]]
Please check [[//rosettacode.org/wiki/Category:ZX_Spectrum_Basic ZX Spectrum page]]
--[[User:Frisian|Frisian]] ([[User talk:Frisian|talk]]) 17:44, 30 April 2020 (UTC)
--[[User:Frisian|Frisian]] ([[User talk:Frisian|talk]]) 17:44, 30 April 2020 (UTC)
Our 2nd reply:
Our 2nd reply: n
actually 249^2*5^2, which is just under the internal limit of a Spectrum Next, & can be madesmaller by shifting indices down to 0
actually 249^2*5 is within the internal limit of a QL, & can be madesmaller by shifting indices down to 0 TO 248
TO 248 and changing the code accordingly. Yet this beta does not have the same flaw as the alpha, as the m loop runs within the 4
and changing the code accordingly. Yet this beta does not have the same flaw as the alpha, as the m loop runs within the 4
others. The error should be different: in taking logs, subtracting them, exponentiating differences, and taking the log of their
others. The error should be different: in taking logs, subtracting them, exponentiating differences and taking the log of their
sums, and comparing that to a log in the p array. That ought to compound rounding errors, so we wouldn't be surprised if it didn't
sums, and comparing that to a log in the p array. That ought to compound rounding errors, so we wouldn't be surprised if it didn't
find the correct solution. Even so, we'd settle for it not finding false solutions. So we'll test it on a 2 MB QL on Q-emuLator
find the correct solution. Even so, we'd settle for it not finding false solutions. So we'll test it on Q-emuLator
sometime next week, and also test trying to balance out the rounding errors on each side of the IF =sign. It seems that Sinclair
sometime next week, and also test trying to balance out the rounding errors on each side of the IF =sign. It seems that Sinclair
BASICs calculate an extra digit in FP functions so as to know which way to round the least significant digit. Comparing the 2.5
BASICs calculate an extra digit in FP functions so as to know which way to round the least significant digit. Comparing the 2.5
powers is to attempt a "meet inthe middle" hack to a discrete log problem. Thus, taking INTs becomes superfluous-& even when
powers is to attempt a "meet inthe middle" hack to a discrete log problem. Thus, taking INTs becomes superfluous - just as when
comparing integers after taking INTs, which seems like shooting yourself in the foot: you may find the correct solution,
comparing integers by taking INTs, which seems like shooting yourself in the foot: you may find the correct solution,
but you also may round some FP Nos the wrong way and thereby find false solutions.
but you also may round some FP Nos the wrong way and thereby find false solutions.
The point is taken that a Spectrum Next is no ZX Spectrum, inwhich case one can revert back to no precalculated differences, and run that at full speed on Fuse.
The point is taken that a Spectrum Next is no ZX Spectrum, inwhich case one can revert back to no precalculated differences, and run that at full speed on Fuse.
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