Well, not sure it's a bug exactly, but one of the main goals of the project is to make the underlying value type generic instead of the hard Double that it is. I have a fork here https://github.com/garyKeorkunian/squants-generic that is my attempt to work through that. I haven't had much time to do that so contributors are certainly welcome. Of course, there's also a number of open items on the issues list.
Hey... hi... thanks for the wonderful library! I wrote some extra utilities to deal with cooking issues. I don't know if it's useful at all to anyone and if it is, I can incorporate it more thoroughly and create a pull request:
https://gist.github.com/rleibman/aae13e38ae0d3490c3b5e5ec3b47bc68
https://gist.github.com/rleibman/aae13e38ae0d3490c3b5e5ec3b47bc68
In particular, I use this to parse recipes, so it's capable of figuring out the ingredients and units, figure out what's the optimal measurement to display ingredients in (depending on the size of containers used for cooking), etc.
@rleibman That looks pretty cool. It seems to be more application specific, however, it could make a great companion project. It may make sense to add the units you created to Squants, but I'm not sure. I'm not an expert on cooking and don't know how precise things like a "dash" really is. What do others think?
@srnb_gitlab my high-school robotics team contributed torque and angular acceleration some time back, we needed it for our own physics simulations (https://github.com/typelevel/squants/pull/227/files)
Guess it just has to be added to the table
Ok... so I have a Quantity... but I have no clue what kind of quantity (I parsed these from recipe ingredients, so I know I have something, just don't know what).
Now... I have a Seq of these... I group them by qty.dimension:
So that I know that within a group they're all the same dimension.
How do I add them? I can't seem to get the types right, something like this:
val qty: Quantity[_ <: Quantity[_]] = parse(str)Now... I have a Seq of these... I group them by qty.dimension:
val groups = quantities.groupBy(_.dimension)So that I know that within a group they're all the same dimension.
How do I add them? I can't seem to get the types right, something like this:
quanties.foldLeft(unit(0))((a, b) => b.plus(a))
Abstracting over the quantity type in many use cases defeats the purpose of the type-safety that Squants provides. Once you have a quantity you need to know what you can do with it. One suggestion I would have for your use case is to split the ingredient list into those that are by mass vs volume. Then creating and scaling the actual quantities should be trivial.
To split the list compare each ingredients unit to those available from Mass and Volume. I'd have to look, but I don't think there are any overlaps.
Ounces, though it's a corner case... in essence that's what I'm doing, grouping by dimension, yes, I could do copy and paste, and then do a whole section casted by mass, another section by volume, another by length (e.g. an inch of ginger) and yet another by dimensionless (a clove of garlic, a head of lettuce, one apple).
I did something super ugly and casted everything to things like Quantity[Nothing]. It's ugly, and it works, but in essence it's exactly what I mean: I know the dimensions match (I grouped, so they must!) and I don't care what they are, just process them.
I did something super ugly and casted everything to things like Quantity[Nothing]. It's ugly, and it works, but in essence it's exactly what I mean: I know the dimensions match (I grouped, so they must!) and I don't care what they are, just process them.
I say "scaling" because when you want to scale up a recipe (4 servings to 100 servings) I assume you will want to show ingredients in larger units.
.... ounces. It's funny how recipes don't differentiate between them (liquid vs dry). They just assume we have the context to know which applies based on the ingredient. So, the questions is, how do you give your application that context?
And yes, with Nothing I lose the type, but I never had it in the first place, which is what Nothing implies, so I think it's all good.
Is https://gitlab.com/srnb/nose workable into Squants? I have so many cases where I want to use it but the Squants way of doing things is so much easier
I'd like to rewrite nose at some point to actually extend Squants but I'm fresh out of time at the moment
I'm wondering if Squants could have
Color as a dimension and Srgb, CIELab, HSV, etc as units
My new usecase is integrating with A frame where all colors need to be rgb style
The way nose does it right now is very limited, you have to know the units at compile time and conversion is handled very weirdly
The only problem I can forsee is the way conversions are handled in Squants, i.e. with Squants, converting from CIELab to CIEXYZ might go CIELab -> sRGB -> CIEXYZ if sRGB were to be the base unit
I would suggest starting out by creating the Quantity, Dimension and Units (extending from Squants types) you need within your project (or a companion project). This isn't too difficult. Once you have validated that it works for your use-case, we can take look to ensure it is general enough to be included in Squants.
Yes, conversions from one non-base unit to another do need to "pass-through" the base, which is essentially calculating a new conversion factor from the two-non base factors. That can be "precision-lossy".
It takes a significantly nonzero amount of time to convert from CIELAB -> sRGB -> CIELAB on my machine
2 replies
I’ve found the following workaround:
scala> squants.thermal.Kelvin(300).toCelsiusScale
res9: Double = 26.850000000000023
OK, this seems to be on purpose: https://github.com/typelevel/squants/blob/master/shared/src/main/scala/squants/thermal/Temperature.scala#L213
But that’s still surprising.
It's the only Dimension in squants where the units don't share a Zero.
Hi Guys. I've just upgraded to latest version of squants and I'm having trouble writing/parsing money values.
GBP(5000).toFormattedString gives me £5000. How do I read that back? GBP(5000).toString gives me 5E3 GBP. How do I read that back? I can read 5000 GBP but the other two seem to fail. I can't figure the trick from the docs.
GBP(5000).toFormattedString gives me £5000. How do I read that back? GBP(5000).toString gives me 5E3 GBP. How do I read that back? I can read 5000 GBP but the other two seem to fail. I can't figure the trick from the docs.
ok, I forked and cloned and added this test to MoneySpec
it should "read its own output from formatted strings given an implicit MoneyContext in scope" in {
implicit val moneyContext = MoneyContext(USD, defaultCurrencySet, Nil)
Money("500 USD").get should be(USD(500))
Money(Money("500 USD").toString) should be(USD(500))
}Gives
Failure(squants.QuantityParseException: Unable to parse Money:Success(5E+2 USD)) was not equal to 5E+2 USD
as far as I can see it's down to this:
def apply(s: String)(implicit fxContext: MoneyContext): Try[Money] = {
val regex = ("([-+]?[0-9]*\\.?[0-9]+) *(" + fxContext.currencies.map(_.code).reduceLeft(_ + "|" + _) + ")").r
s match {
case regex(value, currency) ⇒ Currency(currency).map(Money(value.toDouble, _))
case _ ⇒ Failure(QuantityParseException("Unable to parse Money", s))
}
}