Float format?

[Carl Olsen]

Hi,

For some reason I can't find any good solutions for formating for example floats.

If I have for example 1.23456 and i want it to be formatted to two decimals 1.23?? 

Right now I made my own function, where i multiply by 100 and round it and then divide by 100, but it seems that there should be a better/more efficient way of doing this??

I know this function isn't totally correct, but for my case that is not an issue.

    testFun fl = let first = fl*100

                         sec = round first

                         third = toFloat sec / 100.0

                     in third

    main = asText (testFun 1.2345678)

Cheers 

[Dobes Vandermeer]

I suggest you avoid the built-in formatting altogether, since you never know when your division by 100 will still produce a really long number anyway because of floating-point rounding.

To be certain you get the right result, I would suggest that you multiply by 100, round to an integer, convert to a string, and then insert the decimal point yourself 2 away from the end.  You can optionally trim zeroes from the end, too, if you don't want a strict 2 decimal places.

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[Mikael Bohman]

How do you convert the int to a string ??

[Carl Olsen]

"show" works, but its hard to find documentation on this..

e.g

main = asText <| show 1

[Jeff Smits]

Interesting.. I thought it would be in either the Basisc library docs or the String library docs but I can't find it there...

[Max Goldstein]

These functions are in Prelude and not Basics for some reason. I don't recall Evan publicizing the change in name, and while I agree with it, I wish he'd complete the move or give a reason why we're stuck in this limbo. Not that he's working on any big important projects at the moment or anything.