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Comment by flexagoon | Hacker News Reader

Reactive notebooks are so much better. Using Pluto or Livebook makes you realize how inconvenient and illogical Jupyter is in comparison.

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I mean, there is nothing wrong with state, per se, and yes, this Excel-ish paradigm is awesome.

Although: Most Excel power users have automatic calculations disabled. Why? They want to control when full calculations. If you know that you want to change three things, you can change three things (in the correct order, which you - fair enough - must know), then calculate the rest (F9 in Excel, recalc below in Jupyter if - fair enough - your notebook is in topological order).

In Pluto, you sort of rely on your calculations being quick.

For me, the worst part about Jupyter is not that the cells don't automatically recalculate (I can handle pressing recalc below), but that the output is affected by the order you run the cells in. With Jupyter, there are many situations where to re-run the cell you also have to first re-run all the cells above that one, and it doesn't tell you which ones. Automatic recalculation can be disabled even in reactive notebooks.

It's interesting, I'm not a big notebook user myself, but others (and myself rarely) often take advantage of that feature, because it allows you to e.g. get data from an instrument, but then continue exploring the data using different cells in different orders, e.g. trying different ways of analysing things, e.g. I can cell that gets the data a cell that runs a moving average and a cell that does analyses. When debugging the analysis I can choose if I want to run the moving average data or the normal data, just by choosing I run this or that preceding cell.

Once you take away this way of working, I might as well not work in a notebook at all (which admittedly is my default way of working anyway).

Yeah it is useful. However the problem arises when you share a notebook with someone and they just can’t get it to work either because you forgot to reorder cells or your output depended on some state from a cell you deleted thinking nothing depends on it. You need to restart the kernel and run the notebook all the way through to be sure. Pluto’s reactivity eliminates this issue altogether. It’s a readily reproducible artifact. The functionality you mention would be the default in Pluto btw. Something that reads a sensor will read it only when you run the cell and update all depenents.

It is interesting that they are paying attention to that, as the section on interactivity [1] brings "how to disable a cell" that would prevent its reactivity and anything that depends upon. With some careful placement, you can disable the automatic calculations. Another thing would be tuning the parameter for confirming before a long runtime. Set it to 50 ms, and only run "almost instant things".

[1]https://discourse.julialang.org/t/pluto-1-0-release/137296#p...

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