I have a query which has the math function like below,
math('number1-expected_value').next()
It throws error as
**GremlinServerError: 499: {"detailedMessage":"Unknown function or variable 'cted_value' at pos 20 in expression 'number1 - expected_value'","requestId":"01e3f9e6-3cf2-4af0-bf94-5a4979d488b4","code":"InvalidParameterException"}**
I know, the exp keyword is reserved for exponentiation operation. Is there anyone who knows how to use a keyword as a normal string inside the math function in gremlin?
Note:
when I change the variable as "eexpected_value", it works. If I choose expeected_value, it throws same error. Hence expe and expee make operation of exponen
This appears to be an issue in the Gremlin math step which is built using EXP4J. I have opened the following Jira issue to track within the Apache TinkerPop project: https://issues.apache.org/jira/browse/TINKERPOP-2856
For now, the best workaround as you discovered is just to avoid using variable names that contain any of the math built in function names (like exp).
Related
Posting for two reasons: (1) I was stuck on unhelpful compiler errors for far too long for such a simple issue and I want the next person to google those messages to come upon my (or other) answers, and (2) I still don't understand disallowing a use clause, so my own answer is really incomplete.
In order to call a program in two places with mostly the same arguments, I want to use the '&' to append to a default list inline:
declare
Exit_Code : constant Integer := GNAT.OS_Lib.Spawn (Program_Name => "gprbuild", Args => (Default_GPR_Arguments & new String'(File_Name_Parameter)));
begin
if Exit_Code /= 0 then
raise Program_Error with "Exit code:" & Exit_Code'Image;
end if;
end;
However, the compiler complains that System.Strings.String_List needs a use clause:
operator for type "System.Strings.String_List" is not directly visible
use clause would make operation legal
But inserting use System.Strings.String_List yields:
"System.Strings.String_List" is not allowed in a use clause
I also got this warning:
warning: "System.Strings" is an internal GNAT unit
warning: use "GNAT.Strings" instead
So I substituted GNAT for System in the with and the use clause and got an extra error in addition to the original 'you need a use clause for System.Strings.String_List' one:
"GNAT.Strings.String_List" is not allowed in a use clause
Why is GNAT.Strings.String_List not allowed in a use clause? Section 8.5 on use clauses doesn't seem to state anything on disallowed packages, so is this a compiler bug? Is it possible to define a new package that cannot have a use clause?
In a use clause of the form
use Name;
Name must be a package name. GNAT.Strings.String_List is a subtype name, not a package name.
There are a number of ways to invoke "&" for String_List. The simplest is to use the full name:
GNAT.Strings."&" (Left, Right)
but presumably you want to be able to use it as an operator in infix notation, Left & Right. Ways to achieve this, in decreasing specificity:
function "&" (Left : GNAT.Strings.String_List; Right : GNAT.Strings.String_List) return GNAT.Strings.String_List renames GNAT.Strings."&"; This makes this specific function directly visible.
use type GNAT.Strings.String_List; This makes all primitive operators of the type directly visible.
use all type GNAT.Strings.String_List; This makes all primitive operations of the type (including non-operator operations) directly visible.
use GNAT.Strings; This makes everything in the package directly visible.
Looks like it is a design decision. And many other packages in System follows this rule. From the s-string.ads (package specification for System.String):
-- Note: this package is in the System hierarchy so that it can be directly
-- be used by other predefined packages. User access to this package is via
-- a renaming of this package in GNAT.String (file g-string.ads).
My guess why this is done in that way: because it isn't in the Ada specification, but extension from GNAT.
Is there a way to access all the variables/arguments passed through the command line or variable file (-V option) during robotframework execution. I know in python the execution can access it with 'sys.args' feature.
The answer for getting the CLI arguments is inside your question - just look at the content of the sys.argv, you'll see everything that was passed to the executor:
${args}= Evaluate sys.argv sys
Log To Console ${args}
That'll return a list, where the executable itself (run.py) is the 1st member, and all arguments and their values present the in the order given during the execution:
['C:/my_directories/rf-venv/Lib/site-packages/robot/run.py', '--outputdir', 'logs', '--variable', 'USE_BROWSERSTACK:true', '--variable', 'IS_DEV_ENVIRONMENT:false', '--include', 'worky', 'suites\\test_file.robot']
You explicitly mention variable files; that one is a little bit trickier - the framework parses the files itself, and creates the variables according to its rules. You naturally can see them in the CLI args up there, and the other possibility is to use the built-in keyword Get Variables, which "Returns a dictionary containing all variables in the current scope." (quote from its documentation). Have in mind though that these are all variables - not only the passed on the command line, but also the ones defined in the suite/imported keywords etc.
You have Log Variables to see their names and values "at current scope".
There is no possibility to see the arguments passed to robot.
warning: I'm pretty new to R, sniny and co ==> I don't realize whether this question is interesting.
update : It turns out that it is a shiny question and it seems to be a frequent problem, that is not obvious. Please read all answers, they don't address the same cases.
I have a Data base in DB. Is there a difference between DBtoto <- reactive({DB()}) and DBtoto <- reactive({DB}) ? If so, what is it ?
In fact I don't see what BD() (with parentheses) means.
Yes, there's a difference. DB() is a call to the function named DB. DB is the function itself. If it's not a function, then DB() doesn't make sense, and will trigger a run-time error (unless there's another object somewhere which is a function).
reactive() is a Shiny function, that says the value of its argument may change over time. Usually it would make more sense to think the value of the function call would change, but it's (remotely) possible that the function itself could change.
I also found the first answer of What is “object of type ‘closure’ is not subsettable” error in Shiny? addresses this question. To summary, everything created with 'reactive()' in shiny must be referred as a function.
In my example, if DB was reactive (for instance DB <- reactive(read_DataBase())), then DB() must be referred with parenthesis. For instance, to get the attribute 'x', you must write BD()$x. In my 'DBtoto' example above the first expression holds in the case DB is itself reactive.
I was going through swirl() again as a refresher, and I've noticed that the author of swirl says the command ?matrix is the correct form to calling for a help screen. But, when I run ?matrix(), it still works? Is there a difference between having and not having a pair of parenthesis?
It's not specific to the swirl environment (about which I was entirely unaware until 5 minutes ago) That is standard for R. The help page for the ? shortcut says:
Arguments
topic
Usually, a name or character string specifying the topic for which help is sought.
Alternatively, a function call to ask for documentation on a corresponding S4 method: see the section on S4 method documentation. The calls pkg::topic and pkg:::topic are treated specially, and look for help on topic in package pkg.
It something like the second option that is being invoked with the command:
?matrix()
Since ?? is actually a different shortcut one needs to use this code to bring up that page, just as one needs to use quoted strings for help with for, if, next or any of the other reserved words in R:
?'?' # See ?Reserved
This is not based on a "fuzzy logic" search in hte help system. Using help instead of ? gets a different response:
> help("str()")
No documentation for ‘str()’ in specified packages and libraries:
you could try ‘??str()’
You can see the full code for the ? function by typing ? at the command line, but I am just showing how it starts the language level processing of the expressions given to it:
`?`
function (e1, e2)
{
if (missing(e2)) {
type <- NULL
topicExpr <- substitute(e1)
}
#further output omitted
By running matrix and in general any_function you get the source code of it.
I am using the Kernel Density Estimator toolbox form http://www.ics.uci.edu/~ihler/code/kde.html . But I am getting the following error when I try to execute the demo files -
>> demo_kde_3
KDE Example #3 : Product sampling methods (single, anecdotal run)
Attempt to reference field of non-structure array.
Error in double (line 10)
if (npd.N > 0) d = 1; % return 1 if the density exists
Error in repmat (line 49)
nelems = prod(double(siz));
Error in kde (line 39)
if (size(ks,1) == 1) ks = repmat(ks,[size(points,1),1]); end;
Error in demo_kde_3 (line 8)
p = kde([.1,.45,.55,.8],.05); % create a mixture of 4 gaussians for
testing
Can anyone suggest what might be wrong? I am new to Matlab and having a hard time to figure out the problem.
Thank You,
Try changing your current directory away from the #kde folder; you may have to add the #kde folder to your path when you do this. For example run:
cd('c:\');
addpath('full\path\to\the\folder\#kde');
You may also need to add
addpath('full\path\to\the\folder\#kde\examples');
Then see if it works.
It looks like function repmat (a mathworks function) is picking up the #kde class's version of the double function, causing an error. Usually, only objects of the class #kde can invoke that functions which are in the #kde folder.
I rarely use the #folder form of class definitions, so I'm not completely sure of the semantics; I'm curious if this has any effect on the error.
In general, I would not recommend using the #folder class format for any development that you do. The mathworks overhauled their OO paradigm a few versions ago to a much more familiar (and useful) format. Use help classdef to see more. This #kde code seems to predate this upgrade.
MATLAB gives you the code line where the error occurs. As double and repmat belong to MATLAB, the bug probably is in kde.m line 39. Open that file in MATLAB debugger, set a breakpoint on that line (so the execution stops immediately before the execution of that specific line), and then when the code is stopped there, check the situation. Try the entire code line in console (copy-paste or type it, do not single-step, as causing an uncatched error while single-stepping ends the execution of code in debugger), it should give you an error (but doesn't stop execution). Then try pieces of the code of that code line, what works as it should and what not, eg. does the result of size(points, 1) make any sense.
However, debugging unfamiliar code is not an easy task, especially if you're a beginner in MATLAB. But if you learn and understand the essential datatypes of MATLAB (arrays, cell arrays and structs) and the different ways they can be addressed, and apply that knowledge to the situation on the line 39 of kde.m, hopefully you can fix the bug.
Repmat calls double and expects the built-in double to be called.
However I would guess that this is not part of that code:
if (npd.N > 0) d = 1; % return 1 if the density exists
So if all is correct this means that the buil-tin function double has been overloaded, and that this is the reason why the code crashes.
EDIT:
I see that #Pursuit has already addressed the issue but I will leave my answer in place as it describes the method of detection a bit more.