On Sun, Nov 23, 2014 at 8:47 PM, aparsloe <apars...@clear.net.nz> wrote: > I've written a LaTeX package called "calculyx" which numerically evaluates > mathematical expressions in LyX "before one's eyes" using instant preview. > It is written in the expl3 language of LaTeX3 but is used just like any > other LaTeX package. There is a link at > http://wiki.lyx.org/Examples/Calculyx to a zipped archive currently in a > Dropbox folder, and a screenshot (.png format) of a one-page LaTeX document > and the resulting pdf with a few example calculations at > https://www.dropbox.com/s/7djkyjs44bpraol/Screenshot%202014-11-24%2013.52.07.png?dl=0. > The LaTeX may look complicated, but using LyX, all that is as ever hidden. > One simply enters expressions in the LyX math editor as usual. > > Calculyx requires the three LaTeX3 bundles l3kernel, l3packages and > l3experimental. Because a main routine uses a command that was introduced > to l3kernel on 18 July 2014, the version of l3kernel must be later than > this. The calculational engine for calculyx is the floating point module > l3fp in l3kernel. > > I have tried to ensure as much as possible that calculyx reads expressions > as mathematicians write them. For instance it will "digest" \sin 3x - 3\sin > x + 4\sin^{3} x (for a specified value of x, say \pi/6) without parentheses > around the arguments and with the superscript in the "wrong" but familiar > place. It will "digest" the common arithmetic operators, plus variants like > \times and \div, the familiar trigonometric and hyperbolic functions and > their inverses, the exponential and natural logarithm, fractions (\frac, > \tfrac), square root and \surd, factorials ( using !), binomial coefficients > (\binom, \tbinom), \gcd, sums and products (\sum, \prod) including > "infinite" sums and products, limits (\lim), derivatives (1st and 2nd > order), including Cartesian 2-d and 3-d Laplacians, and definite integrals > in one variable. Results are generally presented in the form: expression = > result. There is also a (multi-column) table creating command and another > which will iterate a function (for the chaos theorists). > > The package contains a novelty that I think could be exploited more widely. > Some calculations are computationally intensive. So as not to burden the > compilation of the pdf with them, these calculations can be "parked" either > in a LyX note or in an inactive branch. Instant preview works in both places > (with a caveat for LyX notes). The result of the calculation can be saved to > a LaTeX control sequence. Calculyx automatically saves such control > sequences to a file. They are then available for inserting elsewhere in the > document -- even at the start, long before the place where the calculation > is performed. If you are prepared to set up a converter and copier, then the > file containing the control sequences can be saved in the document directory > -- or copied to other directories whereby the results of those "parked" > calculations are made available to these other documents. By this means > selected items in LyX notes or inactive branches can play a part in > compilation to pdf. > > Andrew

This is a very cool idea, Andrew. Thanks for implementing that! I don't have time right now to play with new toys but I look forward to testing it someday. Scott