There exists an app which I use for mathematical modeling: http://tydligapp.com<p>It allows you to simply drag and drop dependent variables in multiple formulas to quickly translate real world problems into actual numbers. For example: If I buy amount x of y I can create z which can be sold for $a each. How much do I need to sell to make $b total?<p>Is there anything like this for mac or linux?
Based on what you're looking for (dynamically updating calcs), I would say for most people a spreadsheet fits the bill (Excel, Google Sheets, Calc, Numbers, etc.)<p>The tool you linked to has an intuitive UI and is useful for simple calculations. I can
see it being useful for every day use for folks who aren't that savvy with computers or math.<p>Spreadsheets however are a more much general tool (and only marginally more complex) that will let you do those calculations, but scale those calculations to much more complex models with almost no added complexity.<p>I have seen some really mindboggling things done with spreadsheets (and have done such things myself). But I can as effortlessly whip up the calculations on the demo page in almost the same amount of time.<p>I would say for most people, it would be a better investment of time to learn how to use a spreadsheet.
I don't know of anything like this for Windows, Mac, or Linux, but there should be. For years, I used a truly excellent Palm app called MathPad. One great thing about it was that it had a magic integrated solver: you just entered the relevant equations and whatever variables and constants you had, and if you put in enough, it would solve for whatever hadn't been defined with the press of a "solve" button. This is way better than a spreadsheet that can't support ad hoc calculation of any term.<p>It could handle at least moderately complex systems of equations: I entered all the formulae for the algorithm of Oudin (used to calculate the date of Easter), and it traversed all the equations to reach a correct result. I'd still love to have something like that today, without paying $200! Sadly, I don't think it was open source.
For Mac, I'm a big fan of Numi. You can assign results to variables, use those variables in more calculations, and if you go back and edit a definition, the changes immediately propagate to any other expression using that variable.<p><a href="https://numi.app/" rel="nofollow">https://numi.app/</a>
Quickest? Just fire up a Python REPL ;) You can even use repl.it online in lieu of shell<p>For simulations, computational geometry, computational probability. I prefer Golang scripts. You can subdivide computation using goroutine workers. And it's blazingly fast<p>That said, there is literally no downside to gaining some proficiency with professional tools: Sage / Octave, Matlab, Mathematica, SciPy