Is there a way we can disable undo option in weka, by modifying some configuration file or through GUI?
My dataset is quite large, weka finishes processing fast however it takes a lot of time to save the undo information which is totally unnecessary for me, I found a link http://weka.wikispaces.com/weka_gui_explorer_Explorer.props where they have written that there is an undo option, however I am not sure how would it translate to the application level.
Related
I am trying to use Coldfusion CFPRINT to print UPS labels to a network printer. The starting labels (png files) are great and I can print them locally to the zebra printer and they print and work wonderfully. The barcodes produced by CFPRINT however are of such poor quality that a barcode scanner cannot read them. My research shows that Coldfusion uses the jpedal java library which resizes the images to 72 dpi - which is just not crisp enough for a scanner.
I read about using a jpedal setting: org.jpedal.upscale=2 but I have no clue as to where you would utilize this.
Any suggestions on how to fix this CFPRINT resolution issue using Coldfusion?
(Just to add a bit more detail to the comments)
That is a JVM argument. There are several ways to apply it:
Add the setting to your jvm.config file manually. Backup the file first. Then add -Dorg.jpedal.upscale=2 to the end of the java.args section. Save the changes and restart the CF Server. Do not skip the backup step! Errors in the jvm.config file can prevent the server from starting. So it is important to have a good copy you can restore if needed.
Open the CF Administrator and select Server Settings > Java and JVM > JVM Arguments. Add -Dorg.jpedal.upscale=2 to the end of the arguments. Save the settings and restart the CF server.
Again, I would strongly recommend making a backup of the jvm.config file first. As #Mark noted in the comments, some versions of CF have been known to mangle the jvm.config file, which could prevent the server from starting. But as long as you have a good backup, simply restore it and you are good to go.
IIRC, you could also set the property at runtime, via code. However, timing will be more of a factor. Their API states system properties must be set before accessing JPedal. The docs are not clear on exactly what that means. However, the implication is the system property is only read once, so if you set it too late, it will have no affect.
// untested
sys = createObject("java", "java.lang.System");
prop = sys.getProperties();
prop.setProperty("org.jpedal.upscale", "2");
sys.setProperties(prop);
Side note, I was not familiar with that setting, but a quick search turned up the CF8 Update 1 Release Notes which mention this setting "improves sharpness, but it also doubles the image size" and also increases memory. Just something to keep in mind.
I'm new to webstorm since I started my latest job, and I'm finding some features difficult to adapt to. In particular, the fact that it forces you to save all open changes in all tabs at once is problematic.
I have a somewhat organic method of development, swapping between HTML and LESS frequently until I reach a point where I want to save the files and see what my work has accomplished. Whenever I save an open HTML doc, it saves the incomplete LESS that I just left mid-thought as well, and pops up a compiler error. Is there any way to force webstorm to only save the active tab?
(Aside: Please don't suggest I adjust my mindset or my workflow to adapt to my environment. Not only is that poor usability, it would require me to override an instinct that was developed for good reason: when you reach a milestone, you save it lest something bad happen. Leaving an unsaved doc open makes my eye twitch.)
This has been (sort of) implemented in v7.0. You'll need to dig into Settings > Menus and Toolbars to add "Save Document" to the program menu, and Settings > Keymap if you want to assign a keyboard shortcut (and disable Ctrl+S for Save All).
You may also want to tick "Mark modified tabs with asterisk" under Settings > Editor > Editor Tabs.
Note: You will not be warned if you exit without saving your changes.
I'm looking for a good efficient method for scanning a directory structure for changed files in Windows XP+. Something like how git does it is exactly what I'm looking for, when running a git status it displays all modified files, all new (untracked) files and deleted files very quickly which is exactly what I would like to do.
I have a basic model up and running which performs an initial scan and stores all filenames, size, dates and attributes.
On a subsequent scan it checks if the size, attributes or date have changed and marks as a changed file.
My issue now comes in detecting moved and deleted files. Is there a tried and tested method for this sort of thing? I'm struggling to come up with a good method.
I should mention that it will eventually use ReadDirectoryChangesW to monitor files and alert the user when something changes so a full scan is really a last resort after the initial scan.
Thanks,
J
EDIT: I think I may have described the problem badly. The issue I'm facing is not so much detecting the changes - I have ReadDirectoryChangesW() using IOCP on multiple threads to detected when a change happens, the issue is more what to do with the information. For example, a moved file is reported as a delete followed by a create and a rename comes in 2 parts, old name, followed by new name. So what I'm asking is how to differentiate between the delete as part of a move and an actual delete. I'm guessing buffering the changes and processing batches would be an option but feels messy.
In native code FileSystemWatcher is replaced by ReadDirectoryChangesW. Using this properly is not simple, there is a good baseline to build off here.
I have used this code in a previous job and it worked pretty well. The Win32 API itself (and FileSystemWatcher) are prone to problems that are described in the docs and also discussed in various places online, but impact of those will depending on your use cases.
EDIT: the exact change is indicated in the FILE_NOTIFY_INFORMATION structure that you get back - adds, removals, rename data including old and new name.
I voted Liviu M. up. However, another option if you don't want to use the .NET framework for some reason, would be to use the basic Win32 API call FindFirstChangeNotification.
You can use USN journaling if you are up to it, that is pretty low level (NTFS level) stuff.
Here you can find detailed information and source code included. It is written in C# but most of it is PInvoking C/C++ functions.
I need to create a function that undoes the previous task/addition/change. How do I do this in Borland C++?
(The program stores strings of text in a text file using "list". It is stored and then erased unless I use the save-function I've created.)
I meant creating an undo function in a simple console application by the way.
I'll give yet another answer, but I think that the coverage has been insufficient so far.
The subject is far from trivial, and googling it returns a good number of results. Many applications implement a "undo" operation, and there are many variants.
There are 2 design patterns which can help us out here:
Command: it's a reification of an action
Memento: which consists in storing state (usually implies some form of serialization)
The Command pattern is heavily used in graphic environments because there is usually various ways to accomplish an action. Think of save in Microsoft Word for example:
you can click on the save icon
you can go into File menu and click on Save
you use the shortcut, typically CTRL+S
And of course save is probably implemented in term of save as.
The advantage of the Command pattern here is twofold:
you can create a stack of objects
you can ask every object to implement an undo operation
Now, there are various issues proper to undo:
some operations cannot be undone (for example, consider rm on Linux or the empty trash bin action on Windows)
some operations are difficult to undo, or it may not be natural (you need to store some state, the object is normally destroyed but here you would need to actually store it within the command for the undo action)
generally we think of undo/redo as a stack, some software (graphics mainly) propose to undo items without actually undoing what has been done afterward, this is much more difficult to achieve, especially when the newer actions have been built on top of the to-undo one...
Because there are various problems, there are various strategies:
For a simple Command, you might consider implementing an undo (for example, adding a character can be undone by removing it)
For a more complex Command, you might consider implementing the undo as restoring the previous state (that's where Memento kick in)
If you have lots of complex Command, that could mean lots of Mementos which consumes space, you can then use an approach which consists in only memorizing one Snapshot every 10 or 20 commands, and then redoing the commands from the latest snapshot up to the undone command
In fact, you can probably mix Command and Memento at leisure, depending on the specifics of your system and thus the complexity of either.
I would only considering undoing the last action executed to begin with (using a stack of action then). The functionality of undoing whatever action the user wishes is much more complicated.
To implement Undo, you need to create an "action stack" in your application. There are two basic approaches, though:
Knowing your baseline (the last time the file was saved, or since the file was created), remember every single change that was made so that when something needs to be undone you just throw away the "top-most" item and regenerate the current view from the baseline plus all of the changes. Clicking "Redo" then just puts that item back on the stack. This has a side benefit of being able to trivially remove items anywhere in the stack without messing up other undo/redo options, although there will be special care needed to make sure that the application of "higher" states is as the user intended.
For each action, store off the change that was made to the previous state as well as the change that would be necessary to restore that previous state if you were to undo. Now when the user clicks "Undo," just do the "undo" steps. When clicking "Redo," reapply the changes that were made. In some cases the "Undo" steps will be "here's what the thing looked like before," but that can cause havoc if you want to allow users to remove items that are not on the top of the stack and then need to remove something above it.
The proper choice depends on a lot of factors, including how much data you can/will carry around. Option #1 is in some sense easier but it could become very slow to undo anything if the action stack is large.
You should check out Command Pattern.
Another reference: Using the Command pattern for undo functionality
Also see the memento pattern. Sometimes the intelligence that must go into a command to undo an operation is pretty involved. Drawing objects in a paint program for example. It can be easier just to store a memento and then restore from that memento to implement undo.
You can store snapshots of state. State is the set of data that an action can modify. When you click undo, the current state is replaced by previous. Actually it is not a trivial task, especially if the state is complex.
I've been experimenting lately on that subject. In case you don't need binary compatibility, check out https://github.com/d-led/undoredo-cpp
I have frequently encounter the following debugging scenario:
Tester provide some reproduce steps for a bug. And to find out where the problem is, I try to play with these reproduce steps to get the minimum necessary reproduce steps. Sometimes, luckily I found that when do a minor change to the steps, the problem is gone.
Then the job turns to find the difference in code workflow between these two reproduce steps. This job is tedious and painful especially when you are working on a large code base and it go through a lot code and involve lots of state changes which you are not familiar with.
So I was wondering is there any tools available to compare "code workflow". As I've learned the "wt" command in WinDbg, I thought it might be possible to do it. For example, I can run the "wt" command on some out most functions with 2 different reproduce steps and then compare the difference between outputs. Then it should be easy to found where the code flow starts to diverge.
But the problem with WinDBG is "wt" is quite slow (maybe I should use a log file instead of output to screen) and not very user-friendly (compared with visual studio debugger) ... So I want to ask you guys is there any existing tools available . or is it possible and difficult to develop a "plug-in" for visual studio debugger to support this functionality ?
Thanks
I'd run it under a profiler in "coverage" mode, then use diff on the results to see which parts of the code were executed in one run by not the other.
Sorry, I don't know of a tool which can do what you want, but even if it existed it doesn't sound like the quickest approach to finding out where the lower layer code is failing.
I would recommend to instrument your layer's code with high-level logs so you can know which module fails, stalls, etc. In debug, your logger can write to file, to output debug window, etc.
In general, failing fast and using exceptions are good ways to find out easily where things go bad.
Doing something after the fact is not going to cut it, since your problem is reproducing it.
The issue with bugs is seldom some interal wackiness but usually what the user's actually doing. If you log all the commands that the user enters then they can simply send you the log. You can substitute button clicks, mouse selects, etc. This will have some cost but certainly much less than something that keeps track of every method visited.
I am assuming that if you have a large application that you have good logging or tracing.
I work on a large server product with over 40 processes and over one million lines of code. Most of the time the error in the trace file is enough to identify the location of problem. However sometimes the error I see in the trace file is caused by some earlier code and the reason for this can be hard to spot. Then I use a comparative debugging technique:
Reproduce the first scenario, copy the trace to a new file (if the application is multi threaded ensure you only have the trace for the thread that does the work).
Reproduce the second scenario, copy the trace to a new file.
Remove the timestamps from the log files (I use awk or sed for this).
Compare the log files with winmerge or similar, to see where and how they diverge.
This technique can be a little time consuming, but is much quicker than stepping through thousand of lines in the debugger.
Another useful technique is producing uml sequence diagrams from trace files. For this you need the function entry and exit positions logged consistently. Then write a small script to parse your trace files and use sequence.jar to produce uml diagrams as png files. This is a great way to understand the logic of code you haven't touched in a while. I wrapped a small awk script in a batch file, I just provide trace file and line number to start then it untangles the threads and generates the input text to sequence.jar then runs its to create the uml diagram.