I recently started to learn about Programming through iTunes U, in CS106A at Stanford through the videos. And I am now working with Karel or so to write.
I followed the instructions about downloading everything to the letter but when I start to write a set of methods, the system tells me that it can't find the version that I am using and in the Assignment1 package, when I am looking through Eclipse, every sub-portion of Assignment1 has a warning triangle with it.
public class *CollectNewspaperKarel* extends SuperKarel {
public void run() {
collectnewspaperKarel is underlined in yellow.
And every program, is underlined in yellow. When I try to change by generating versions of the software it still can't run it. What should I do, because I can't even try any combination that I create? Karel is still standing still in all the given worlds.
as you need to do this task only once, left button on triangle and try other solutions - suppress warning or add default serial version ID, worked for me.
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I am using R and tried some.function but I got following error message:
Error: could not find function "some.function"
This question comes up very regularly. When you get this type of error in R, how can you solve it?
There are a few things you should check :
Did you write the name of your function correctly? Names are case sensitive.
Did you install the package that contains the function? install.packages("thePackage") (this only needs to be done once)
Did you attach that package to the workspace ?
require(thePackage) (and check its return value) or library(thePackage) (this should be done every time you start a new R session)
Are you using an older R version where this function didn't exist yet?
Are you using a different version of the specific package? This could be in either direction: functions are added and removed over time, and it's possible the code you're referencing is expecting a newer or older version of the package than what you have installed.
If you're not sure in which package that function is situated, you can do a few things.
If you're sure you installed and attached/loaded the right package, type help.search("some.function") or ??some.function to get an information box that can tell you in which package it is contained.
find and getAnywhere can also be used to locate functions.
If you have no clue about the package, you can use findFn in the sos package as explained in this answer.
RSiteSearch("some.function") or searching with rdocumentation or rseek are alternative ways to find the function.
Sometimes you need to use an older version of R, but run code created for a newer version. Newly added functions (eg hasName in R 3.4.0) won't be found then. If you use an older R version and want to use a newer function, you can use the package backports to make such functions available. You also find a list of functions that need to be backported on the git repo of backports. Keep in mind that R versions older than R3.0.0 are incompatible with packages built for R3.0.0 and later versions.
Another problem, in the presence of a NAMESPACE, is that you are trying to run an unexported function from package foo.
For example (contrived, I know, but):
> mod <- prcomp(USArrests, scale = TRUE)
> plot.prcomp(mod)
Error: could not find function "plot.prcomp"
Firstly, you shouldn't be calling S3 methods directly, but lets assume plot.prcomp was actually some useful internal function in package foo. To call such function if you know what you are doing requires the use of :::. You also need to know the namespace in which the function is found. Using getAnywhere() we find that the function is in package stats:
> getAnywhere(plot.prcomp)
A single object matching ‘plot.prcomp’ was found
It was found in the following places
registered S3 method for plot from namespace stats
namespace:stats
with value
function (x, main = deparse(substitute(x)), ...)
screeplot.default(x, main = main, ...)
<environment: namespace:stats>
So we can now call it directly using:
> stats:::plot.prcomp(mod)
I've used plot.prcomp just as an example to illustrate the purpose. In normal use you shouldn't be calling S3 methods like this. But as I said, if the function you want to call exists (it might be a hidden utility function for example), but is in a namespace, R will report that it can't find the function unless you tell it which namespace to look in.
Compare this to the following:
stats::plot.prcomp
The above fails because while stats uses plot.prcomp, it is not exported from stats as the error rightly tells us:
Error: 'plot.prcomp' is not an exported object from 'namespace:stats'
This is documented as follows:
pkg::name returns the value of the exported variable name in namespace pkg, whereas pkg:::name returns the value of the internal variable name.
I can usually resolve this problem when a computer is under my control, but it's more of a nuisance when working with a grid. When a grid is not homogenous, not all libraries may be installed, and my experience has often been that a package wasn't installed because a dependency wasn't installed. To address this, I check the following:
Is Fortran installed? (Look for 'gfortran'.) This affects several major packages in R.
Is Java installed? Are the Java class paths correct?
Check that the package was installed by the admin and available for use by the appropriate user. Sometimes users will install packages in the wrong places or run without appropriate access to the right libraries. .libPaths() is a good check.
Check ldd results for R, to be sure about shared libraries
It's good to periodically run a script that just loads every package needed and does some little test. This catches the package issue as early as possible in the workflow. This is akin to build testing or unit testing, except it's more like a smoke test to make sure that the very basic stuff works.
If packages can be stored in a network-accessible location, are they? If they cannot, is there a way to ensure consistent versions across the machines? (This may seem OT, but correct package installation includes availability of the right version.)
Is the package available for the given OS? Unfortunately, not all packages are available across platforms. This goes back to step 5. If possible, try to find a way to handle a different OS by switching to an appropriate flavor of a package or switch off the dependency in certain cases.
Having encountered this quite a bit, some of these steps become fairly routine. Although #7 might seem like a good starting point, these are listed in approximate order of the frequency that I use them.
If this occurs while you check your package (R CMD check), take a look at your NAMESPACE.
You can solve this by adding the following statement to the NAMESPACE:
exportPattern("^[^\\\\.]")
This exports everything that doesn't start with a dot ("."). This allows you to have your hidden functions, starting with a dot:
.myHiddenFunction <- function(x) cat("my hidden function")
I had the error
Error: could not find function some.function
happen when doing R CMD check of a package I was making with RStudio. I found adding
exportPattern(".")
to the NAMESPACE file did the trick. As a sidenote, I had initially configured RStudio to use ROxygen to make the documentation -- and selected the configuration where ROxygen would write my NAMESPACE file for me, which kept erasing my edits. So, in my instance I unchecked NAMESPACE from the Roxygen configuration and added exportPattern(".") to NAMESPACE to solve this error.
This error can occur even if the name of the function is valid if some mandatory arguments are missing (i.e you did not provide enough arguments).
I got this in an Rcpp context, where I wrote a C++ function with optionnal arguments, and did not provided those arguments in R. It appeared that optionnal arguments from the C++ were seen as mandatory by R. As a result, R could not find a matching function for the correct name but an incorrect number of arguments.
Rcpp Function : SEXP RcppFunction(arg1, arg2=0) {}
R Calls :
RcppFunction(0) raises the error
RcppFunction(0, 0) does not
Rdocumentation.org has a very handy search function that - among other things - lets you find functions - from all the packages on CRAN, as well as from packages from Bioconductor and GitHub.
If you are using parallelMap you'll need to export custom functions to the slave jobs, otherwise you get an error "could not find function ".
If you set a non-missing level on parallelStart the same argument should be passed to parallelExport, else you get the same error. So this should be strictly followed:
parallelStart(mode = "<your mode here>", N, level = "<task.level>")
parallelExport("<myfun>", level = "<task.level>")
You may be able to fix this error by name spacing :: the function call
comparison.cloud(colors = c("red", "green"), max.words = 100)
to
wordcloud::comparison.cloud(colors = c("red", "green"), max.words = 100)
I got the same, error, I was running version .99xxx, I checked for updates from help menu and updated My RStudio to 1.0x, then the error did not come
So simple solution, just update your R Studio
This is an odd question, I know.
Earlier this week, I was browsing hacker news and glossed past an article about the power of C# 6. I meant to 'pocket' the link at the time but I didn't and now I can't find the article again.
Long story short, there was an example of code which looked roughly like this...
using static Variables;
public class Blah
{
public Blah()
{
s = "something"
Console.WriteLine(s);
}
}
... as if to say, somehow it was possible using some magical combination of C# 6 features to remove the 'var' element of that equation and have valid code.
I'm struggling to see how that's possible without some extra Roslyn magic and even then, I'd struggle.
If you know where the article is please let me know. If not, is this even remotely possible? I'm fairly confident it would be an odd thing to do,..I'm just intrigued.
Thanks in advance.
I am trying to write a simple parser to read MusicXML and play it back. I am using JFugue 5.0.3. The library simply hangs in the middle half the time.
My code:-
public void play() throws ParserConfigurationException, ParsingException, IOException {
MusicXmlParser_J parser_j = new MusicXmlParser_J();
StaccatoParserListener listener = new StaccatoParserListener();
parser_j.addParserListener(listener);
parser_j.parse(musicXMLFile);
Player player = new Player();
final Pattern musicXMLPattern = listener.getPattern();
player.play(musicXMLPattern);
}
This code fails after attempting to build MusicXML file with a useless error message:-
attempting to build file
Oops something went wrong. The error isConnection timed out
and it works sometimes and when it does it works like a charm and within milliseconds. What is JFugue trying to download stuff over the network? A little debugging revealed it works by downloading
Few questions to the people who work on this :-
Why doesn't this code work with MusicXMLParserListener class? This class fails with an arbitrary null pointer exception because it expects Staccato parser to be defined. Why? And what is the deal with two different listeners for MusicXML - MusicXMLParserListener_J and MusicXMLParserListener_R? Don't expose broken stuff to consumers please.
I had read that JFugue supports MusicXML and I expected this to work without an issue.
Are there examples of JFugue working with MusicXML?
The two different parsers you see are a result of MusicXML capability in JFugue 5.0+ not being fully completed yet (which is mentioned on the JFugue download page). These were two implementations contributed by two developers in the open source community. Based on your issue, I have just updated the JFugue distribution: I moved one of the parsers out, and renamed the other one simply MusicXmlParser.
It turns out that the other parser, MusicXmlParser_R, is the better of the two. Of course, no user would have had any idea about that. My apologies for exposing an incomplete capability. For the record, "Oops, something went wrong" is not a JFugue error message, but "attempting to build file" was in MusicXmlParser_J, which is now out of the code.
The following code, which is from test/org.jfugue.musicxml, demonstrates the use of MusicXmlParser.
MusicXmlParser musicXmlParser = new MusicXmlParser();
StaccatoParserListener spl = new StaccatoParserListener();
musicXmlParser.addParserListener(spl);
musicXmlParser.parse(new File("src/test/resources/HelloWorldMusicXml.xml"));
Please note that there is no implementation of MusicXmlParserListener for JFugue 5.0 at the moment. I have updated the download page to make this clear.
The MusicXML capabilities within JFugue are entirely community-contributed.
I have a vb6 app that uses Word interop to create a few reports. In the introduction of these reports, there are some instructions in 4 textboxes around an image.
Recently and suddenly the top two textboxes started appearing on the next page, and I can't figure out why. When I step through the code and watch the word document getting built, everything positions itself correctly, however, if I compile the application, the error reappears.
Any suggestions?
Use late-bound calls to Word. This does not mean to remove reference to Microsoft Word Xxx Object Library, just alter your Dims like this
Dim oWord As Object '--- was Word.Application'
Dim oDoc As Object '--- was Word.Document'
...
oDoc.Protect wdAllowOnlyReading '--- keep using enums'
Could it be some 'rounding' difference? For instance if you compare two float point values for equality, the result can subtly depend on the specific compiler/interpreter implementation.
I would like to suggest to trim down your code to the minimum showing the different behaviors. That might clear things up already. If not, please post it here to let us help you.
Maybe you are running the compiled version as a different user than the one running VB when you debug? Maybe this could cause what you are describing, if the two users have some different Word settings.
Is it possible that the compiled version finds a different version of the .dot file?
It may be very helpful if you show the code you use to create the Word document, because then someone here might notice something that can be sensible to moving to a compiled version.
Do you have any code in events that rely on timing, such as Form_Activate, Load, or Unload? I've seen those things behave very differently when stepping through code and when compiled, especially on newer, faster machines.
Very simple question that is apparently impossible to find a decent answer to: How can I make Visual Basic 6 stop changing my ^##*ing variable casing!?!
I know that the general opinion of a great many VB users is that this "feature" is actually quite helpful, but I doubt that they use it much with any source control system. This is absolutely INFURIATING when you are trying to collaborate on a project of any significant size with several other developers. If ignored, you produce thousands of false-positive "changes" to your files (even ones with no actual code changes!) that pollute the revision history and make it near impossible in some cases to locate the actual change that took place.
If you don't ignore it (like my office, where we have been forced to implement a "no unneeded case change" policy), you spend 5x the time you would normally on each commit because you have to carefully revert out VB's "corrections" on every file, sometimes reverting hundreds of lines to put in a one line change.
Surely there must be a setting, plugin, hack, etc. out there that can remove this unwanted "feature"? I am willing to take any method I can get as long as it doesn't require me to pick through piles of phantom diffs. And to squash a couple of complaints up front: No, I can't turn off case detection in my diff tool, that's not the point. No, we can't just make the case changes globally. We're working with hundreds of thousands of LOC being worked on by multiple developers spanning many years of development. Synchronizing that is not feasible from a business standpoint. And, finally: No, we cannot upgrade to VB.net or port to another language (as much as I would love to).
(And yes, I am just a tiny bit peeved at the moment. Can you tell? My apologies, but this is costing me time and my company money, and I don't find that acceptable.)
Depending on your situation adding
#If False Then
Dim CorrectCase
#End If
might help.
Here is a real world scenario and how we solved it for our 350k LOC VB6 project.
We are using Janus Grid and at some point all the code lines which referenced DefaultValue property of JSColumn turned to defaultValue. This was an opportunity to debug the whole IDE nuisance.
What I found was that a reference to MSXML has just been added and now the IDE picks up ISchemaAttributes' defaultValue property before the Janus Grid typelib.
After some experiments I found out that the IDE collects "registered" identifiers in the following order:
Referenced Libraries/Projects from Project->References in the order they are listed
Controls from Project->Components (in unknown order)
Source Code
So the simple fix we did was to create a dummy class/interface with methods that hold our proper casing. Since we already had a project-wide typelib we referenced from every project before anything other typelib, this was painless to do.
Here is part of the IDL for our IUcsVbIntellisenseFix interface:
[
odl,
uuid(<<guid_here>>),
version(1.0),
dual,
nonextensible,
oleautomation
]
interface IUcsVbIntellisenseFix : IDispatch {
[id(1)] HRESULT DefaultValue();
[id(2)] HRESULT Selector();
[id(3)] HRESULT Standalone();
...
}
We added a lot of methods to IUcsVbIntellisenseFix, some of them named after enum items we used to misspell and whatever we wanted to fix. The same can be done with a simple VB class in a common library (ActiveX DLL) that's referenced from every project.
This way our source code at some point converged to proper casing because upon check-out the IDE actually fixed the casing as per IUcsVbIntellisenseFix casing. Now we can't misspell enums, methods or properties even if we try to.
SIMPLE WAY: Dim each variable in the case that you want. Otherwise, VBA will change it in a way that is not understandable.
Dim x, X1, X2, y, Yy as variant
in a subroutine will change ALL cases to those in the Dim statement
I can sympathise. Luckily we're allowed to turn off case sensitivity in our version control diff tool!
It seems the VB6 IDE automatic case-correction occasionally changes case in variable declarations and references, perhaps depending on the order in which modules are listed in the VBP file? But the IDE doesn't tell you that the file needs to be saved. So the problem only shows up when you saved the file because of another edit. We briefly tried to prevent this by checking out all the files in a project and setting the case carefully, but it didn't go away.
I suppose you could list the variable names that are affected - the usual suspects are one letter names like "I", "X" and "Y", perhaps because they are used in standard event handlers like MouseDown. Then write an add-in that'll search for all declarations " As" and force the case to upper. Run the add-in on your modules before you check them in. You might be able to trigger the add-in to run automatically when you save in VB6.
EDIT: Something I've just thought of: adapt Fred's answer. From now on, every time you check in a file, add a block at the top to establish canonical case for the usual suspects. If nothing else, it's easier than reverting hundreds of lines by hand. Eventually you will have this block in every file & maybe then the problem will stop happening.
#If False Then
Dim I, X, Y ' etc '
#End If
I standardised the case across the codebase, normally by using the examples above (Dim CorrectCase), and removing it again.
I then triggered VB to save EVERY file, by doing a case sensitive search/replace of "End" with "End" (no functional change, but enough to get VB to resave).
Once that was done, I could then do a single commit to standardise the case, making it MUCH easier to keep on top of it at a later date.
In this example VB6 was changing the case of the following line following a typo I made when referencing a library: -
Dim MyRecordset As ADODB.REcordset
Ugly, and now every other instance of an ADODB.REcordset thus acquired the new misspelling. I fixed this as follows: -
Type in a new declaration as follows
Dim VB6CasingSucks AS ADODB, Recordset
Note the comma and space after ADODB. Hit [ENTER] for VB6 to check the line.
At this point all instances of REcordset change back to Recordset.
Delete your new declaration.
I don't know if this fix will help with enums/other variable names.
Specifically for controlling the case of enum values, there is a VB6 IDE add-in which may be helpful. Enums seem to have a slightly unique version of this problem.
As described in the link below:
The VB6 IDE has an annoying quirk when it comes to the case of Enum
members. Unlike with other identifiers, the IDE doesn't enforce the
case of an Enum member as it was declared in the Enum block. That
occasionally causes an Enum member that was manually written to lose
its original case, unless a coder typed it carefully enough.
...
However, if a project contains a lot of Enums and/or a particular Enum
has a lot of members, redeclaring the members in each of them can get
quite tedious fast. ...
Ref: http://www.vbforums.com/showthread.php?778109-VB6-modLockEnumCase-bas-Enforce-Case-of-Enums
...load and unload the add-in as needed via the Add-In Manager
dialog box. Usage is as simple as selecting the entire Enum block,
right-clicking and then choosing the "Lock Enum Case" context menu
item.
I have a similar problem:
in a bas module there I wrote :
Private sub bla_bla()
Dim K as integer
End Sub
so in a class module the Dim k as integer will automatically be replaced by IDE become 'Dim K as integer' <-- it's not logical but then:
I correct the bas module become:
Private sub bla_bla()
Dim k as integer
End Sub
then magically the problem in the class module was solved (still be k and not automatically replaced by IDE become K). Sorry I'm poor in English
I don't think there's any to do it. The IDE will change the case of the variable name to whatever it is when it's declared. But, honestly, back in the day I worked on several large VB6 projects and never found this to be a problem. Why are people on your development team constantly changing variable declarations? It seems like you have not established a clear variable naming policy that you enforce. I know your upset, so no offense, but it might be your policies that are lacking in this regard.
Unfortunately, according to this SO thread, alternate VB6 IDEs are hard to come by. So, your best bet is to solve this problem via policy. Or move to VB.NET. :)
Wow. I've spent a lot of time programming in VB6 and I have no idea what you're on about. The only thing I can think you're referring to is that intellisense will change the capitalization of variable names to match their declarations. If you're complaining about that, I would have to wonder why the hell they've been entered any other way to begin with. And if that is your problem, no, there's no way to disable it that I'm aware of. I'd suggest you, in one go, check out every file, make sure the caps on the declarations and uses of variables all match and check back in.