apply

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I am making a Box2d game for the iPhone. I need to apply a force on a body which represents my main character. The body is actually a rectangle on top of a circle connected using a revolute joint. I am using this as the skeleton for my character who is supposed to be running through the game(any suggestions or feedback on this too would be appreciated). I need a force to be applied continuously so that it keeps him moving. What would be the best way to do this? I am currently applying linear velocity inside the tick method. _world

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: is there a way to make a query such that if certain field exists it will apply WHERE like condition on that field and if it pass will add that document to the result. If such field doesn't exist, it will immediately add that document to the result? 回答1: How about something like this: db.stackoverflow.find({ $or: [ { howmuch: { $exists:false } }, { howmuch:5 } ]}) In the stackoverflow collection, this will find all documents that do not have the howmuch field plus all documents that do have howmuch set to 5. 文章来源: Mongodb query - apply

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: It seems apply will not re-assemble 3D arrays when operating on just one margin. Consider: arr <- array( runif(2*4*3), dim=c(2, 4, 3), dimnames=list(a=paste0("a", 1:2), b=paste0("b", 1:4), c=paste0("c", 1:3)) ) # , , c = c1 # # b # a b1 b2 b3 b4 # a1 0.7321399 0.8851802 0.2469866 0.9307044 # a2 0.5896138 0.6183046 0.7732842 0.6652637 # # , , c = c2 # b # a b1 b2 b3 b4 # a1 0.5894680 0.7839048 0.3854357 0.56555024 # a2 0.6158995 0.6530224 0.8401427 0.04044974 # # , , c = c3 # b # a b1 b2 b3 b4 # a1 0.3500653 0.7052743 0.42487635 0.5689287 #

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: In the Io programming language, is there an equivalent to lisp's apply function. So for example I have a method to wrap writeln : mymeth := method ( //do some extra stuff writeln ( call message arguments )) ) At the moment this just prints the list, and doesn't evaluate it's contents as if they were it's own args. 回答1: Thanks to that person who suggested evalArgs (not sure where your comment went). Anyway that has resolved for my situation, although unfortunately not in general I guess. You can achieve what I describe by doing :

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm having a bit of trouble altering a duplicated pandas DataFrame and not having the edits apply to both the duplicate and the original DataFrame. Here's an example. Say I create an arbitrary DataFrame from a list of dictionaries: In [67]: d = [{'a':3, 'b':5}, {'a':1, 'b':1}] In [68]: d = DataFrame(d) In [69]: d Out[69]: a b 0 3 5 1 1 1 Then I assign the 'd' dataframe to variable 'e' and apply some arbitrary math to column 'a' using apply: In [70]: e = d In [71]: e['a'] = e['a'].apply(lambda x: x + 1) The problem arises in that the apply

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a pandas dataframe 'df' with two columns 'A' and 'B', I have a function with two arguments def myfunction(B, A): # do something here to get the result return result and I would like to apply it row-by-row to df using the 'apply' function df['C'] = df['B'].apply(myfunction, args=(df['A'],)) but I get the error ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all(). whats happening here, it seems it takes df['A'] as the whole series! not just the row entry from that series as required.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I need to apply a style in code ike this: TextBlock.Style = TryFindResource("MyStyle") as Style; that will be updated dynamically when the resource dictionary is changed (i.e. skin is replaced at runtime). In other words I need the equivalent to using a dynamic resource like this: <TextBlock Style="{DynamicResource MyStyle}" /> 回答1: Try using SetResourceReference . textBlock.SetResourceReference(TextBlock.StyleProperty, "MyStyle") 文章来源: How do I apply a dynamic style in code at runtime?

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Assuming we have the following case class: case class CasePerson(firstName: String) And we also define a companion object for it: object CasePerson { def apply() = new CasePerson( "XYZ" ) } Notice that in the example above I explicitly defined a companion object with an apply method, without defining the the default apply method: // This "default" apply has the same argument as the primary constructor of the case class def apply(firstName : String) = new CasePerson(firstName) Q: So where does Scala gets this "default" apply? I explicitly

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I am wondering if there is a way to do a pandas dataframe apply function in parallel. I have looked around and haven't found anything. At least in theory I think it should be fairly simple to implement but haven't seen anything. This is practically the textbook definition of parallel after all.. Has anyone else tried this or know of a way? If no one has any ideas I think I might just try writing it myself. The code I am working with is below. Sorry for the lack of import statements. They are mixed in with a lot of other things. def

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a matrix like A= [ 1 2 4 2 3 1 3 1 2 ] and I would like to calculate its cumulative sum by row and by column, that is, I want the result to be B = [ 1 3 7 3 8 13 6 12 19 ] Any ideas of how to make this in R in a fast way? (Possibly using the function cumsum) (I have huge matrices) Thanks! 回答1: A one-liner: t(apply(apply(A, 2, cumsum)), 1, cumsum)) The underlying observation is that you can first compute the cumulative sums over the columns and then the cumulative sum of this matrix over the rows. Note: When doing the rows, you have to