When running a Reliability analysis I got en error warning that there were too few cases for the analysis. My dataset has no missing cases or missing values. I tried re-importing the dataset from Excel which didn't fix the issue, nor did importing as a CSV.
I identified the problematic variable (points_16359) using missing values analysis:
However there are no missing data for that variable in the dataset; when I run a frequency analysis I get:
And even more strange, the MVA on just that same variable shows no missing cases:
I only have one recordset active. I restarted SPSS and repeated all the above with the same results.
I did find a workaround with this syntax:
RECODE points_16539 (SYSMIS=SYSMIS) (ELSE=Copy) INTO recd_16539.
But I have no idea what is causing the problem, and since this is part of an automated analysis I routinely do, it breaks my syntax. Does anyone have an explanation or better workaround? Thanks in advance.
Related
I need to generate random but lexically correct sentences with my words included. The sentence doesn't have to consist entirely of my words. But the more of them the better.
I have already searched through a lot of resources related to machine learning, but everywhere they write about generating RANDOM texts. I can't influence the result in any way by specifying the presence of at least a couple of my words as a condition.
Perhaps someone on this resource knows about repositories with similar libraries or APIs where I can get something like this?
After a week of searching, I can say that there is no ready-to-use library or service for this.
If you data scientist, you may found this problem interesting for a creation your own startup, i think.
Consider the following smt2 file generated with the help of Klee.
I am trying to evaluate it using z3. However, z3 hangs forever. Specifically, when the formula is UNSAT, z3 runs for ever and does not produce any result.
Is formula size is big?
Is there any issue while using logic theory AUFBV?
May I get some suggestions to improve the z3 performance.
Each assert statement having some common subexpression. Is it possible to improve the z3 performance by solving subexpression separately?
This is going to be impossible to answer as the SMT-lib file you've linked is undecipherable for a non-KLEE user. I recommend asking KLEE folks directly using your original program that gave rise to this. Failing that, try to reduce the SMT2Lib to a minimum and see if you can at least hand-annotate to see what it's trying to do.
Regarding your question for common subexpressions: You have to experiment to find out. But the way most such solvers are constructed, they /will/ discover common subexpressions themselves and reuse lemmas about them automatically as they convert your input to an internal representation. So, it'd surprise me if it helped in any significant way to do this by hand; unless the input is really massive. (The example you linked isn't really that big so I doubt that's an issue.)
I know that syntax analysis is needed to determine if the series of tokens given are appropriate in a language (by parsing these tokens to produce a syntax tree), and detect errors occurred during the parsing of input code, which caused by grammatically incorrect statements.
I also know that semantic analysis is then performed on the syntax tree to produce an annotated tree ,checking aspects that are not related to the syntactic form( like type correctness of expressions and declaration prior to use) , detecting errors occurred during the execution of the code, after it has been parsed as grammatically correct.
However , the following issue is not clear to me :
In case of syntax error detected by the syntax analyzer - does it mean that should be no semantic analysis ? Or perhaps the recovery from errors (in syntax analysis) should make the semantic analysis possible to be carried out?
When you compile an incorrect program, you generally want the compiler to inform you about as many problems as possible, so that you can fix them all before attempting to compile the program again. However, you don't want the compiler to report the same error many times, or to report things which are not really errors but rather the result of the compiler getting confused by previous errors.
Or am I projecting my expectations on you? Perhaps I should have written that whole paragraph in first person, since it is really about what I expect from a compiler. Perhaps you have different expectations. Or perhaps your expectations are similar to mine. Whatever they are, you should probably write your compiler to satisfy them. That's basically the point of writing your own compiler.
So, if you share my expectations, you probably want to do as much semantic analysis as you can feel reasonably confident about. You might, for example, be able to do type checking inside some functions, because there are no syntax errors within those functions. On the other hand, that's a lot of work and there's always the chance that the resulting error messages will not be helpful.
That's not very precise, because there really is no definitive answer. But you should at least be able to answer your own question on your own behalf. If your compiler does a lousy job of error reporting and you find that frustrating when you try to use your compiler, then you should work on making the reports better. (But, of course, time is limited and you might well feel that your compiler will be better if it optimises better, even though the error reports are not so great.)
I've just started using activerecord-import, and it is much faster than the one by one inserts I was doing before. I'm currently inserting in batches of 500 records, and wondered what other people have found to be a good number for the batches? I know there is no "one size fits all" answer. I'm just looking for some guidance by others that have experience with activerecord-import. I've looked at the documentation and Googled it, and haven't found anything.
Additional info fwiw: I'm using Postgres, and saving model objects, not columns and arrays with values.
Any help is appreciated.
activerecord-import will break the import into groups based on max-allowed-packet for your database adapter, so you shouldn't run into any problems. Optimization is another issue.
The only thing I would be concerned with is the memory allocation - if you've already allocated all the objects and are just feeding them in batches to an import call, I'd do them all at once.
If you're generating the objects dynamically for each batch (while reading from file, for example), you should do some testing and see what the memory usage looks like for various batch sizes.
I had a question as to whether or not it was possible to get either the minted package, or the texments package, to syntax color like you would see in xcode. Not necessarily the same colors, that does not matter, but to get all of the variable types and things like that to highlight.
An example of this would be that when I used minted, things like #synthesize, float, int, all highlight but NSArray or NSMutableDictionary do not.
Does anyone know how to change this or possibly add more formatting to the package. I have searched, but nothing has been too helpful.
Thanks in advance for any assistance!
Unfortunately, that’s not (easily) possible.
minted and texments rely on lexical analysis of the code. Lexical analysis is comparably easy and efficient but it is only the first stage of parsing a source code.
As a result, lexical analysis can recognise keywords, strings, comments and identifiers but it cannot tell identifiers apart. To do that, a parser would need to parse the whole code basis (comprising multiple files) and build an abstract syntax tree.
This is much more complex and time-consuming, and generally too inefficient for syntax colouring. For that reason, most code highlighting tools don’t perform such an in-depth analysis.
Xcode needs to fully parse the code anyway (for error messages, debugging and other things) and maintains a database of parsing information for each project. This allows it to provide more sophisticated code highlighting and still perform well. You might notice that if you load a single code file (not part of a project) in Xcode, no full syntax colouring of variable names will be performed either.