DISCLAIMER: I am aware that the following is extremely bad practice. I just need a quick-fix for debugging purposes.
I am trying to run a Julia package that is using both JuMP.jl and LightXML.jl.
I get the following error:
WARNING: both JuMP and LightXML export "name"; uses of it in module JEMSS must be qualified
LightXML is added first, so I'd like to make a copy of name, then let JuMP override.
What is the syntax to do this?
The name function consists of:
name(::LightXML.XMLElement)
name(::LightXML.XMLNode)
name(::LightXML.XMLAttr)
Based on the discussion in the comments, I should write that the warning tells you that if you want to use name in your code, you should specify which module's name you want to use. You do this by qualifying it with the module/package name such as LightXML.name or JuMP.name.
If you want to create an alias for, say, LightXML.name, this is also possible.
using LightXML
# make `name2` be an alias for `LightXML.name`
const name2 = LightXML.name # `name2` refers to `LightXML.name` but `LightXML.name` still exists
using JuMP
using JuMP: name # tell the compiler `name` without qualifiers refer to `JuMP.name` so you do not have to qualify it
This actually does not give change the name of LightXML.name but rather create an alias for LightXML.name. After this, you can write name2 instead of LightXML.name or still use LightXML.name as is.
Note that const is an important detail here otherwise whenever you use name2 Julia will have to look it up whether what name2 refers has changed and this will degrade performance.
The other thing to note is that if you want to use name without qualifiers to refer to JuMP.name, you write using JuMP: name to indicate to the compiler which name should be used (since there are still two names). You should, however, do this before using name without any qualifier in your code.
The following therefore will not work.
julia> using LightXML
julia> name # we used `name` here to refer to `LightXML.name `
julia> using JuMP # this will give you the same warning in your question
julia> using JuMP: name # this will give you a warning and be **ignored**
# `name` continues to refer to `LightXML.name` rather than `JuMP.name`
Related
So I'm just starting to learn Eiffel. One of the first exercises in the book I'm using says to make a function that does base^exp without using ^. I've copied my code below.
class
APPLICATION
inherit
ARGUMENTS
create
make
feature {NONE} -- Initialization
make
-- Run application.
do
create power(2;3)
printf("2 to the power of 3 is " + answer)
end
power(base : REAL; exp : INTEGER) : REAL
-- computers base raised to the bower of exp without using ^
local
remain : INTEGER
do
remain := exp
if remain = 0 then
result := 1
else
from
until
remain = 0
loop
result := result * result
remain := remain -1
end
end
end
end
How do I use this? Do I need it on the same level as feature{NONE}'s make? I know how I'm calling it is wrong, and I can't find anything in the chapter I just read, or online on how to pass parameters into it or how to use it's results.
There are several issues with the original code:
create is used to create an object, but you are not going to create anything, but to get a result of a computation of the function power by calling it. Therefore the keyword create is not needed.
You are using an entity answer to report the result of evaluation on a screen. However it is not declared anywhere. I believe the proper place would be a local variable declaration section.
The entity answer is not initialized to the result of the function power. This is usually done by an assignment instruction.
Feature arguments are separated by a comma, not by a semicolon.
From the original code it's unclear what is the type of the variable answer. Assuming it matches the type of the function power, before adding it to a string, it needs to be converted to a string. This is done by calling the feature out.
The standard feature for printing a string to a console is print, not printf.
Combining the critical points above, we get
make
-- Run application.
local
answer: REAL
do
answer := power(2, 3)
print ("2 to the power of 3 is " + answer.out)
end
After that the code can be compiled. Now less critical points:
It is a good style to put features to a dedicated feature clauses, so I would add a line like feature -- Basic operations before the feature power.
The implementation of the feature power has at least two problems. I'm not going to detail them here, but would give two hints instead:
by default numeric Result is initialized to 0, this needs to be taken into account for operations that use it without first assigning any other value
even though an argument base is passed to the function power it remains unused in the original version of the code
When I run the following regression,
reg subject inSchool#treatment#male
I get comparisons in reference to inSchool=0, treatment=0, and male=0, but I would like to be able to change the reference variables.
For example I would like to have all the comparisons done in reference to inSchool=1,treatment=0, and male=1.
I have used the following characteristic command but it doesn't seem to have an effect.
char inSchool[omit] 1 male[omit] 1
Am I having a syntax issue or is there no way to choose which variable to omit using #
Thanks in advance!
From help fvvarlist:
You can specify the base level of a factor variable by using the ib. operator.
Sometimes I accidentally declare variables that have the name of a function.
Here is a constructed example:
max(4:5) % 5
max(1:10)=10*ones(10,1); % oops, should be == instead of =
max(4:5) % [10 10]
At the moment I always find this out the hard way and it especially happens with function names that I don't use frequently.
Is there any way to let matlab give a warning about this? It would be ideal to see this on the right hand side of the screen with the other warnings, but I am open to other suggestions.
Since Matlab allows you to overload built-in functionality, you will not receive any warnings when using existing names.
There are, however, a few tricks to minimize the risk of overloading existing functions:
Use explicitFunctionNames. It is much less likely that there is a function maxIndex instead of max.
Use the "Tab"-key often. Matlab will auto-complete functions on the path (as well as variables that you've declared previously). Thus, if the variable auto-completes, it already exists. In case you don't remember whether it's also a function, hit "F1" to see whether there exists a help page for it.
Use functions rather than scripts, so that "mis-"assigned variables in the workspace won't mess up your code.
I'm pretty sure mlint can also check for that.
Generally I would wrap code into functions as much as possible. That way the range of such an override is limited to the scope of the function - so no lasting problems, besides the accidental assumption of course.
When in doubt, check:
exist max
ans =
5
Looking at help exist, you can see that "max" is a function, and shouldn't be assigned as a variable.
>> help exist
exist Check if variables or functions are defined.
exist('A') returns:
0 if A does not exist
1 if A is a variable in the workspace
2 if A is an M-file on MATLAB's search path. It also returns 2 when
A is the full pathname to a file or when A is the name of an
ordinary file on MATLAB's search path
3 if A is a MEX-file on MATLAB's search path
4 if A is a MDL-file on MATLAB's search path
5 if A is a built-in MATLAB function
6 if A is a P-file on MATLAB's search path
7 if A is a directory
8 if A is a class (exist returns 0 for Java classes if you
start MATLAB with the -nojvm option.)
This question bugged me for years now and can't seem to find good solution still. I working in PHP and Java but it sounds like this maybe language-agnostic :)
Say we have a standard status reference table that holds status ids for some kind of entity. Further let's assume the table will have just 5 values, and will remain like this for a long time, maybe edited occasionally with addition of a new status.
When you fetch a row and need to see what status it is you have 2 options(as I see it at least) - put it straight ID values(magic numbers that is) or use a named constant. Latter seem much cleaner, the question though is where those named constants should leave? In a model class? In a class that uses this particular constant? Somewhere else?
It sounds like what you're wanting to do is an enumerated value.
This is a value that has a literal name mapped to a constant value, this would be something like
Statusone = 1
Statustwo = 2
Then anywhere in your program you could refrenece statusone which the compiler would see as 1.
I'm not sure if this exists in php but I'm pretty sure it does in java
EDIT In response to some comments
I would typically put enumerated values in some kind of global namespace, or if you only need them when you are using that class spefically you can put them at the class level.
I've tried
CONSTANTS seq = <<5,6,7>>
but TLC gives me a syntax error:
Error: TLC found an error in the
configuration file at line 1. It was
expecting = or <- and didn't find it.
I've also tried to include the Sequences module in the configuration file, to no avail.
So... what do I have to do to assign a sequence?
I don't remember ever facing this problem and my TLC is too rusty to try and give you a first hand answer (I just restarted using the TLA+ toolbox).
From the post linked bellow, however, I figure that you can't instantiate constants with sequences through the TLC config files.
http://bbpress.tlaplus.net/topic/creating-a-sequence-from-a-set
Even though the question is old, leaving an answer may help future TLAers.
You can't directly assign to a constant in the TLA+ file. If you're using the toolbox, write CONSTANTS seq, then in the model add the tuple you want as an ordinary assignment.
So it turns out that you need a separate .tla file for that. Suppose you have "Main.tla" as you source file. You want MyConst to have value <<1,2,3>>. TLA+ toolbox generates MC.tla where it puts the constants:
---- MODULE MC ----
EXTENDS Main, TLC
const_uniq12345 = <<1,2,3>>
====
in MC.cfg, there will be the line
CONSTANT MyConst <- const_uniq12345
Note that MyConst = const_uniq12345 won't work -- if you use = instead of <-, MyConst will contain model value const_uniq12345 instead of <<1, 2, 3>>
I used https://github.com/hwayne/tlacli to be able to run TLC from command line (TLA toolbox has awful UX), and I was able to supply a tuple constant with help of extra .tla file like this. I used meaningful name instead of const_uniq12345 too, of course. Had to call java -cp /path/to/tla2tools.jar ... manually, though (got the full command using --show-script option of tlacli), because currently tlacli doesn't handle <- in the config.