Search Results

Search found 9954 results on 399 pages for 'mean'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 48/399 | < Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >

  • How can I neatly clean my R workspace while preserving certain objects?

    - by briandk
    Suppose I'm messing about with some data by binding vectors together, as I'm wont to do on a lazy sunday afternoon. x <- rnorm(25, mean = 65, sd = 10) y <- rnorm(25, mean = 75, sd = 7) z <- 1:25 dd <- data.frame(mscore = x, vscore = y, caseid = z) I've now got my new dataframe dd, which is wonderful. But there's also still the detritus from my prior slicings and dicings: > ls() [1] "dd" "x" "y" "z" What's a simple way to clean up my workspace if I no longer need my "source" columns, but I want to keep the dataframe? That is, now that I'm done manipulating data I'd like to just have dd and none of the smaller variables that might inadvertently mask further analysis: > ls() [1] "dd" I feel like the solution must be of the form rm(ls[ -(dd) ]) or something, but I can't quite figure out how to say "please clean up everything BUT the following objects."

    Read the article

  • Using ggplot in R

    - by g256
    I have a time series cvs file like this (in var there are the values): Hour,Date,Type,val1,val2,val3,val4,val5,val6..... 0100,0153,aaa, 0100,0153,bbb, 0100,0153,ccc, 0100,0153,ddd, 0200,0153,aaa, 0200,0153,bbb, 0200,0153,ccc, 0200,0153,ddd, . . 0100,0154,aaa, 0100,0154,bbb, 0100,0154,ccc, 0100,0154,ddd, . . I would like to use ggplot to plot the barplot mean of the time series of val1,val2,... for each type. One plot for each type except for ccc and ddd that should be considered as one type, so for this I should first sum up the value, then take the mean, then plot). So three plot at the end. Thanks for advice.

    Read the article

  • How to permanently prevent specific part of a file from being committed in git?

    - by boutta
    I have cloned a remote SVN repository with git-svn. I have modified a pom.xml file in this cloned repo in a way that the code compiles. This setup is exclusive for me. Thus I don't want to push the changes back on the remote repo. Is there a way to prevent this (partial) change of a file from being committed into the repo? I'm aware of the fact, that I could use a personal branch, but this would mean certain merging overhead. Are there other ways? I've looked into this question and this one, but they are for rather temporal changes. Update: I'm also aware of the .gitignore possibilities, but this would mean to exclude the file completely.

    Read the article

  • Why does the assignment operator return a value and not a reference?

    - by Nick Lowman
    I saw the example below explained on this site and thought both answers would be 20 and not the 10 that is returned. He wrote that both the comma and assignment returns a value, not a reference. I don't quite understand what that means. I understand it in relation to passing variables into functions or methods i.e primitive types are passed in by value and objects by reference but I'm not sure how it applies in this case. I also understand about context and the value of 'this' (after help from stackoverflow) but I thought in both cases I would still be invoking it as a method, foo.bar() which would mean foo is the context but it seems both result in a function call bar(). Why is that and what does it all mean? var x = 10; var foo = { x: 20, bar: function () {return this.x;} }; (foo.bar = foo.bar)();//returns 10 (foo.bar, foo.bar)();//returns 10

    Read the article

  • What is a Custom Class?

    - by John Saunders
    Many questions here on SO ask about custom classes. I, on the other hand, have no idea what they're talking about. "Custom class" seems to mean the same thing I mean when I say "class". What did I miss, back in the '80s, that keeps me from understanding? I know that it's possible to purchase a packaged system - for Accounting, ERP, or something like that. You can then customize it, or add "custom code" to make the package do things that are specific to your business. But that doesn't describe the process used in writing a .NET program. In this case, the entire purpose of the .NET Framework is to allow us to write our own code. There is nothing useful out of the box.

    Read the article

  • [Python] Help me : how i can deal with web page !

    - by Str1k3r
    hello every one... am looking for modules or functions let's me joins in id web !!!! i mean like i told python go to hotmail.com then go to signup ! how i can do that i mean how i can tell python go to hotmail.com then find some thing called signup in source page then i tell him join to him ....etc i hope you understand my idea ! ** am thinking on urllib2 .. maybe it's can do that? am just new in python

    Read the article

  • How to set UITableViewCell highlighted image

    - by SmartTree
    I want to launch a method every time when user just highlights a cell (doesn't select it) in UITableView. Could you tell me please, how is it possible to do this ? I want to do it because I have a custom cell with a pictures on it and I want to change pictures every time when user highlights the cell. UPD: By highlight I mean that user just highlights a cell and don't release the finger from it. By select I mean when didSelectRowAtIndexPath is being launched (so the user releases the finger from the cell after he presses on it)

    Read the article

  • Are there any real life uses for the Java byte primitive type?

    - by Thorbjørn Ravn Andersen
    For some inexplicable reason the byte primitive type is signed in Java. This mean that valid values are -128..127 instead of the usual 0..255 range representing 8 significant bits in a byte (without a sign bit). This mean that all byte manipulation code usually does integer calculations and end up masking out the last 8 bits. I was wondering if there is any real life scenario where the Java byte primitive type fits perfectly or if it is simply a completely useless design decision? EDIT: The sole actual use case was a single-byte placeholder for native code. In other words, not to be manipulated as a byte inside Java code.

    Read the article

  • Birthday effect - clarification needed plz.

    - by Mark
    Please help interpret the Birthday effect as described in Wikipedia: A birthday attack works as follows: 1) Pick any message m and compute h(m). 2) Update list L. Check if h(m) is in the list L. 3) if (h(m),m) is already in L, a colliding message pair has been found. else save the pair (h(m),m) in the list L and go back to step 1. From the birthday paradox we know that we can expect to find a matching entry, after performing about 2^(n/2) hash evaluations. Does the above mean 2^(n/2) iterations through the above entire loop (i.e. 2^(n/2) returns to step 1), OR does it mean 2^(n/2) comparisons to individual items already in L.

    Read the article

  • Why is writeSTRef faster than if expression?

    - by wenlong
    writeSTRef twice for each iteration fib3 :: Int -> Integer fib3 n = runST $ do a <- newSTRef 1 b <- newSTRef 1 replicateM_ (n-1) $ do !a' <- readSTRef a !b' <- readSTRef b writeSTRef a b' writeSTRef b $! a'+b' readSTRef b writeSTRef once for each iteration fib4 :: Int -> Integer fib4 n = runST $ do a <- newSTRef 1 b <- newSTRef 1 replicateM_ (n-1) $ do !a' <- readSTRef a !b' <- readSTRef b if a' > b' then writeSTRef b $! a'+b' else writeSTRef a $! a'+b' a'' <- readSTRef a b'' <- readSTRef b if a'' > b'' then return a'' else return b'' Benchmark, given n = 20000: benchmarking 20000/fib3 mean: 5.073608 ms, lb 5.071842 ms, ub 5.075466 ms, ci 0.950 std dev: 9.284321 us, lb 8.119454 us, ub 10.78107 us, ci 0.950 benchmarking 20000/fib4 mean: 5.384010 ms, lb 5.381876 ms, ub 5.386099 ms, ci 0.950 std dev: 10.85245 us, lb 9.510215 us, ub 12.65554 us, ci 0.950 fib3 is a bit faster than fib4.

    Read the article

  • Can someone please clarify the Birthday Effect for me?

    - by Mark
    Please help interpret the Birthday effect as described in Wikipedia: A birthday attack works as follows: Pick any message m and compute h(m). Update list L. Check if h(m) is in the list L. if (h(m),m) is already in L, a colliding message pair has been found. else save the pair (h(m),m) in the list L and go back to step 1. From the birthday paradox we know that we can expect to find a matching entry, after performing about 2^(n/2) hash evaluations. Does the above mean 2^(n/2) iterations through the above entire loop (i.e. 2^(n/2) returns to step 1), OR does it mean 2^(n/2) comparisons to individual items already in L.

    Read the article

  • Why does String.Equals(Object obj) check to see if this == null?

    - by m-y
    // Determines whether two strings match. [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)] public override bool Equals(Object obj) { //this is necessary to guard against reverse-pinvokes and //other callers who do not use the callvirt instruction if (this == null) throw new NullReferenceException(); String str = obj as String; if (str == null) return false; if (Object.ReferenceEquals(this, obj)) return true; return EqualsHelper(this, str); } The part I don't understand is the fact that it is checking for the current instance, this, against null. The comment is a bit confusing, so I was wondering what does that comment actually mean? Can anyone give an example of how this could break if that check was not there, and does this mean that I should also place that check in my classes?

    Read the article

  • Dynamic Unpivot : SSIS Nugget

    - by jamiet
    A question on the SSIS forum earlier today asked: I need to dynamically unpivot some set of columns in my source file. Every month there is one new column and its set of Values. I want to unpivot it without editing my SSIS packages that is deployed Let’s be clear about what we mean by Unpivot. It is a normalisation technique that basically converts columns into rows. By way of example it converts something like this: AccountCode Jan Feb Mar AC1 100.00 150.00 125.00 AC2 45.00 75.50 90.00 into something like this: AccountCode Month Amount AC1 Jan 100.00 AC1 Feb 150.00 AC1 Mar 125.00 AC2 Jan 45.00 AC2 Feb 75.50 AC2 Mar 90.00 The Unpivot transformation in SSIS is perfectly capable of carrying out the operation defined in this example however in the case outlined in the aforementioned forum thread the problem was a little bit different. I interpreted it to mean that the number of columns could change and in that scenario the Unpivot transformation (and indeed the SSIS dataflow in general) is rendered useless because it expects that the number of columns will not change from what is specified at design-time. There is a workaround however. Assuming all of the columns that CAN exist will appear at the end of the rows, we can (1) import all of the columns in the file as just a single column, (2) use a script component to loop over all the values in that “column” and (3) output each one as a column all of its own. Let’s go over that in a bit more detail.   I’ve prepared a data file that shows some data that we want to unpivot which shows some customers and their mythical shopping lists (it has column names in the first row): We use a Flat File Connection Manager to specify the format of our data file to SSIS: and a Flat File Source Adapter to put it into the dataflow (no need a for a screenshot of that one – its very basic). Notice that the values that we want to unpivot all exist in a column called [Groceries]. Now onto the script component where the real work goes on, although the code is pretty simple: Here I show a screenshot of this executing along with some data viewers. As you can see we have successfully pulled out all of the values into a row all of their own thus accomplishing the Dynamic Unpivot that the forum poster was after. If you want to run the demo for yourself then I have uploaded the demo package and source file up to my SkyDrive: http://cid-550f681dad532637.skydrive.live.com/self.aspx/Public/BlogShare/20100529/Dynamic%20Unpivot.zip Simply extract the two files into a folder, make sure the Connection Manager is pointing to the file, and execute! Hope this is useful. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

    Read the article

  • Kdevelop 4.5.2 on Ubuntu 12.04 ? errors

    - by canatan
    I want to install kdevelop 4.5.2 on Ubuntu 12.04 I ran sudo apt-get install kdevelop 4.5 in the terminal and the installation had a few errors but things looked fine. if i run kdevelop i get the following error Could not find KTextEditor::Factory, check your installation: Make sure that Kate is installed, KDEDIRS is set properly and that you ran kbuildsycoca4. I tried to install kate but I got errors since ubuntu 12.04 does not support kdevelop 4.5.2 officially. Does that mean I'll have to build from source ?

    Read the article

  • The Game vs The Game Engine?

    - by Milo
    I was wondering if somebody could tell me how the game and the game engine fit into game development. Specifically what I mean is, the game engine does not actually have a game. So where I'm unclear about is basically, do game developpers build an engine, then create a new class that inherits from engine which becomes the game? Ex: class ShooterGame : public Engine { }; So basically i'm unclear on where the game code fits into the engine. Thanks

    Read the article

  • "E: Package ‘synaptic’ has no installation candidate" when trying to install synaptic

    - by rohit
    ilshat@lpt:~$ sudo apt-get install synaptic Reading package lists… Done Building dependency tree Reading state information… Done Package synaptic is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package ‘synaptic’ has no installation candidate I have tried doing a sudo apt-get update but that doesn't work.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 44 45 46 47 48 49 50 51 52 53 54 55  | Next Page >