“Calculation Reimagined”

Reimagined indeed! Tydlig has become my calculator of choice. Brilliant.

Most apps simulate the functionality of pre-digital technologies—e-books whose pages you can “turn,” e-calculators whose buttons you can “press”, e-canvases on which you can “paint”, and so on—but this app uses the digital medium far more creatively, in several ways.

The first is that it allows the user to link the components of any calculation to the components of any other calculation, to move those components around freely around the work surface, and to change the value of any of those components at will. Any change in a component is immediately reflected in all the calculations that share that component. In this way, the app functions like a spreadsheet, but without the rigidity of rows and columns of cells. Tidy lines and arrows indicate what is connected to what, and the ability to give each component a label that travels with it wherever it goes makes it easy to see what the inputs and outputs actually mean.

The second significant innovation is the app’s graphing capabilities. These will seem strange indeed to anyone used to thinking of graphs as representations of equations like y = mx + b, or f(x)=log x, because the app has no way of explicitly representing variables. Instead, if the graphing option is selected from a menu associated with a calculation, the app graphs the general function of which the calculation is a particular instance. This works well, but it surely takes some getting used to.

There are some design oddities that should perhaps be considered outright flaws: there is a “copy” command, but no “paste.” (So what does “copy” do?) The work surface (“canvas”) is of infinite extent, but there is only one. There is, therefore, no way to save a set of calculations (having to do, say, with home remodelling costs), and start a new set of calculations (having to do, perhaps, with your child’s physics homework) without creating an unbearably cluttered and confusing workspace. The function set is good—it includes factorials, a random number generator, and a modulus operator, none of which appear reliably in most calculator interfaces. The only operator missing is a reciprocal.

Tydlig is quick, elegant, flexible, ingenious, and practical. I hope its developers receive the encouragement they have earned, and that they keep adding to the app’s power and usability.

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