Is there any reason that this syntax shouldn't work in Qlikview load script??
Let v_myNumber = year(today());
Let v_myString = '2017-08';
If left($(v_myString),4) = text($(v_myNumber)) Then
'do something
Else
'do something else
End If;
I've tried both ways where I convert variable string to number and evaluate against the number variable directly and this way. They won't evaluate to equivalence when they should..
Left function is expecting a string as is getting something else as a parameter. As you are currently doing, the function will be called as Left(2017-08, 4) which is unhandle by QlikView.
If you use Left('$(v_myString)',4), it will evaluate as Left('2017-08', 4) as work as expected. Just adding quotes around the variable it should work.
Although QlikView calls them variables, they should really be seen as "stuff to replaced (at sometimes evaluated) at runtime", which is slightly different from a standard "variable" behaviour.
Dollar sign expansion is a big subject, but in short:
if you are setting a variable - no need for $().
if you are using a variable - you can use $(). depends on its context.
if you are using a variable that needs to be evaluated - you have to use $().
for example in a load script: let var1 = 'if(a=1,1,2)' - here later on the script you will probably want to use this variable as $(var1) so it will be evaluated on the fly...
I hope its a little more clear now. variable can be used in many ways at even can take parameters!
for example:
var2 = $1*$2
and then you can use like this: $(var2(2,3)) which will yield 6
For further exploration of this, I would suggest reading this
Related
I'm calling a function in Elm and some of the variable names I'm passing as parameters are kind of long, so I'd rather not put it all on 1 line. But I'm having trouble figuring out how to do that.
Normally, from experience with other languages, I'd imagine it might look something like this:
result =
Dict.foldr \
dataTransformationFunction \
0 \
initialStateDict
That obviously didn't work though. I tried using |> and <|, but I couldnt get anything using those to compile (since 0 and the other parameters arent functions that takes arguments, I couldn't pipe).
Am I doing something wrong here, or is there no way to add a line break in Elm code?
Looks like I forgot to try the simplest option; you don't need a special character/operator to do a line break if none of your parameters require any (more) arguments.
This is perfectly legal:
result =
Dict.foldr
(myFunction)
0
initialStateDict
IC=IC
ACC=ACC
v_statement='ACC = '1052502',0.035,IC = 'IC130',0.0675'
v_decode_out=DECODE(TRUE,v_statement,0)
i am getting error
is the above expression correct.Is there anyway we can achieve this
There are two problems in your query
First, the v_statement variable you have written won't be validated. If you
really want to write a string in this format, then use pipes to append as
'ACC='||1052502||','||0.035||'IC='||'IC130'||','||'0.0675'
Note that you cannot loop quotes.
Second, the reason your decode statement wont work is because of the data type mismatch. True is a boolean value and v_statement is a string. Any variable expansion would happen during run time but not before that. So, informatica does not allow you this kind of decode statement, unless you are comparing some kind of string input/variable with another string or any other data type for that matter
Also, decide on your case
When it is If ACC else IC to be evaluated (this seems to be your case)
v_decode_out=DECODE(ACC,'1052502',0.035,DECODE(IC,'IC130',0.0675))
When it is both ACC and IC together
v_decode_out=DECODE(TRUE,ACC='1052502' and/or IC='IC130',0.035,0.0675)
These are fundamental concepts. It's advisable that you try out everything available on internet before you post a question here, because someone could easily down rate you if they feel that you have not put any effort at all to find an answer yourself.
Cheers!
the v_statement variable you have written won't be validated. If you really want to write a string in this format, then use pipes to append.
I'm hoping someone can help answer my question, perhaps with an idea of where to go or whether what I'm trying to do is not possible with the way I want to do it.
I've been asked to write a set of rules based on the data held by our ERP form components or variables.
Unfortunately, these components and variables cannot be accessed or used outside of the ERP, so I can't use SQL to query the values and then build some kind of SQL query.
They'd like the ability to put statements like these:
C(MyComponentName) = C(MyOtherComponentName)
V(MyVariableName) > 16
(C(MyComponentName) = "") AND V(MyVariableName) <> "")
((C(MyComponentName) = "") OR C(MyOtherComponentName) = "") AND V(MyVariableName) <> "")
This should be turned into some kind of query which gets the value of MyComponentName and MyOtherComponentName and (in this case) compares them for equality.
They don't necessarily want to just compare for equality, but to be able to determine whether a component / variable value is greaterthan or lessthan etc.
Basically it's a free-form statement that gets converted into something similar to an IF statement.
I've tried this:
Sub TestCondition()
Dim Condition as string = String.Format("{0} = {1}", _
Component("MyComponent").Value, Component("MyOtherComponent").Value)
If (Condition) Then
' Do Something
Else
' Do Something Else
End If
End Sub
Obviously, this does not work and I honestly didn't think it would be so simple.
Ignoring the fact that I'd have to parse the line, extract the required operators, the values from components or variables (denoted by a C or V) - how can I do this?
I've looked at Expression Trees but these were confusing, especially as I'd never heard of them, let alone used them. (Is it possible to create an expression tree for dynamic if statements? - This link provided some detail on expression trees in C#)
I know an easier way to solve this might be to simply populate the form with a multitude of drop-down lists, so users pick what they want from lists or fill in a text box for a specific search criteria.
This wouldn't be a simple matter as the ERP doesn't allow you to dynamically create controls on its forms. You have to drag each component manually and would be next to useless as we'd potentially want at least 1 rule for every form we have (100+).
I'm either looking for someone to say you cannot do this the way you want to do it (with a suitable reason or suggestion as to how I could do it) that I can take to my manager or some hints, perhaps a link or 2 pointing me in the right direction.
If (Condition) Then
This is not possible. There is no way to treat data stored in a string as code. While the above statement is valid, it won't and can't function the way you want it to. Instead, Condition will be evaluated as what it is: a string. (Anything that doesn't boil down to 0 is treated as True; see this question.)
What you are attempting borders on allowing the user to type code dynamically to get a result. I won't say this is impossible per se in VB.Net, but it is incredibly ambitious.
Instead, I would suggest clearly defining what your application can and can't do. Enumerate the operators your code will allow and build code to support each directly. For example:
Public Function TestCondition(value1 As Object, value2 As Object, op as string) As Boolean
Select Case op
Case "="
Return value1 = value2
Case "<"
Return value1 < value2
Case ">"
Return value1 > value2
Case Else
'Error handling
End Select
End Function
Obviously you would need to tailor the above to the types of variables you will be handling and your other specific needs, but this approach should give you a workable solution.
For my particular requirements, using the NCalc library has enabled me to do most of what I was looking to do. Easy to work with and the documentation is quite extensive - lots of examples too.
I'm using GameMaker:Studio Pro and trying to execute a script stored in a variable as below:
script = close_dialog;
script_execute(script);
It doesn't work. It's obviously looking for a script named "script". Anyone know how I can accomplish this?
This question's quite old now, but in case anyone else ends up here via google (as I did), here's something I found that worked quite well and avoids the need for any extra data structures as reference:
scriptToCall = asset_get_index(scr_scriptName);
script_execute(scriptToCall);
The first line here creates the variable scriptToCall and then assigns to it Game Maker's internal ID number for the script you want to call. This allows script_execute to correctly find the script from the ID, which doesn't work if you try to pass it a string containing the script name.
I'm using this to define which scripts should be called in a particular situation from an included txt file, hence the need to convert a string into an addressable script ID!
You seem to have some confusion over how Game Maker works, so I will try to address this before I get around to the actual question.
GML is a rather simple-minded beast, it only knows two data types: strings and numbers. Everything else (objects, sprites, scripts, data structures, instances and so on) is represented with a number in your GML code.
For example, you might have an object called "Player" which has all kinds of fancy events, but to the code Player is just a constant number which you can (e.g.) print out with show_message(string(Player));
Now, the function script_execute(script) takes as argument the ID of the script that should be executed. That ID is just a normal number. script_execute will find the script with that ID in some internal table and then run the script.
In other words, instead of calling script_execute(close_dialog) you could just as well call script_execute(14) if you happened to know that the ID of close_dialog is 14 (although that is bad practice, since it make the code difficult to understand and brittle against ID changes).
Now it should be obvious that assigning the numeric value of close_dialog to a variable first and then calling script_execute on that variable is perfectly OK. In the end, script_execute only cares about the number that is passed, not about the name of the variable that this number comes from.
If you are thinking ahead a bit, you might wonder whether you need script_execute at all then, or if you could instead just do this:
script = close_dialog;
script();
In my opinion, it would be perfectly fine to allow this in the language, but it does not work - the function call operator actually does care about the name of the thing you try to call.
Now with that background out of the way, on to your actual question. If close_dialog is actually a script, your suggested code will work fine. If it is an extension function (or a built-in function -- I don't own Studio so what do I know) then it does not actually have an ID, and you can't call it with script_execute. In fact, you can't even assign close_dialog to a variable then because it does not have any value in GML -- all you can do with it then is call it. To work around this though, you could create a script (say, close_dialog_script which only calls close_dialog, which you can then use just as above.
Edit: Since it does not seem to work anyway, check whether you have a different resource by the name of close_dialog (perhaps a button sprite). This kind of conflict could mean that close_dialog gives you the ID of the sprite, not of the script, while calling the script directly would still work.
After much discussion on the forums, I ended up going with this method.
I wrote a script called script_id()
var sid;
sid = 6; //6 = scriptnotfound script :)
switch (argument0) {
case "load_room":
sid = 0;
break;
case "show_dialog":
sid = 1;
break;
case "close_dialog":
sid = 3;
break;
case "scrExample":
sid = 4;
break;
}
return sid;
So now I can call script_execute(script_id("close_dialog"));
I hate it, but it's better than keeping a spreadsheet... in my opinion.
There's also another way, with execute_string();
Should look like this:
execute_string(string(scriptName) + "();");
When I´m using MATLAB, sometimes I feel the need to make comments on some variables. I would like to save these comments inside these variables. So when I have to work with many variables in the workspace, and I forget the context of some of these variables I could read the comments I put in every one of them. So I would like to comment variables and keep the comments inside of them.
While I'm of the opinion that the best (and easiest) approach would be to make your variables self-documenting by giving them descriptive names, there is actually a way for you to do what you want using the object-oriented aspects of MATLAB. Specifically, you can create a new class which subclasses a built-in class so that it has an additional property describing the variable.
In fact, there is an example in the documentation that does exactly what you want. It creates a new class ExtendDouble that behaves just like a double except that it has a DataString property attached to it which describes the data in the variable. Using this subclass, you can do things like the following:
N = ExtendDouble(10,'The number of data points')
N =
The number of data points
10
and N could be used in expressions just as any double value would. Using this example subclass as a template, you could create "commented" versions of other built-in numeric classes, with the exception of those you are not allowed to subclass (char, cell, struct, and function_handle).
Of course, it should be noted that instead of using the ExtendDouble class like I did in the above example, I could instead define my variable like so:
nDataPoints = 10;
which makes the variable self-documenting, albeit with a little more typing needed. ;)
How about declaring another variable for your comments?
example:
\>> num = 5;
\>> numc = 'This is a number that contains 5';
\>> whos
...
This is my first post in StackOverflow. Thanks.
A convenient way to solve this is to have a function that does the storing and displaying of comments for you, i.e. something like the function below that will pop open a dialog box if you call it with comments('myVar') to allow you to enter new (or read/update previous) comments to variable (or function, or co-worker) labeled myVar.
Note that the comments will not be available in your next Matlab session. To make this happen, you have to add save/load functionality to comments (i.e. every time you change anything, you write to a file, and any time you start the function and database is empty, you load the file if possible).
function comments(name)
%COMMENTS stores comments for a matlab session
%
% comments(name) adds or updates a comment stored with the label "name"
%
% comments prints all the current comments
%# database is a n-by-2 cell array with {label, comment}
persistent database
%# check input and decide what to do
if nargin < 1 || isempty(name)
printDatabase;
else
updateDatabase;
end
function printDatabase
%# prints the database
if isempty(database)
fprintf('no comments stored yet\n')
else
for i=1:size(database,1)
fprintf('%20s : %s\n',database{i,1},database{i,2});
end
end
end
function updateDatabase
%# updates the database
%# check whether there is already a comment
if size(database,1) > 0 && any(strcmp(name,database(:,1)))
idx = strcmp(name,database(:,1));
comment = database(idx,2);
else
idx = size(database,1)+1;
comment = {''};
end
%# ask for new/updated comment
comment = inputdlg(sprintf('please enter comment for %s',name),'add comment',...
5,comment);
if ~isempty(comment)
database{idx,1} = name;
database(idx,2) = comment;
end
end
end
Always always always keep the Matlab editor open with a script documenting what you do. That is, variable assignments and calculations.
Only exceptions are very short sessions where you want to experiment. Once you have something -- add it to the file (It's also easier to cut and paste when you can see your entire history).
This way you can always start over. Just clear all and rerun the script. You never have random temporaries floating around in your workspace.
Eventually, when you are finished, you will also have something that is close to 'deliverable'.
Have you thought of using structures (or cells, although structures would require extra memory use)?
'>> dataset1.numerical=5;
'>> dataset1.comment='This is the dataset that contains 5';
dataset1 =
numerical: 5
comment: 'This is the dataset that contains 5'