For my program, I have multiple tables inside of each other for organization and readability. These tables can look something like this
local buttons = {
loadingScreen = {
bLoadingEnter = function()
end
}, ...
}
What I want to do is find the first element named bLoadingEnter in the table. I dont know that the element named bLoadingEnter will be in loadingScreen. I've thought of getting all the keys in the table then check them. I couldn't get that to work. Any help would be appreciated!
If execution speed is in any way relevant, the answer is:
you don't
Looking up a key in a nested table takes a lot longer than looking it up in just a normal table. The next problem is that of uniqueness. Two or more nested tables can have the same key with different values, which may lead to odd bugs down the road. You'd either have to check for that when inserting (making your code even slower) or just hope things miraculously go well and nothing explodes later on.
I'd say just use a flat table. If your keys are well named (like bLoadingEnter) you'll be able to infer meaning from the name either way, no nesting required.
That being said, nested tables can be a good option, if most of the time you know what path to take, or when you have some sort of ordered structure like a binary search tree. Or if speed really isn't an important factor to consider.
Okay try
for _, item in ipairs(buttons) do
if item.bLoadingEnter ~= nil then
return item.bLoadingEnter
end
end
Related
I have data containing candidates who look for a job. The original data I got was a complete mess but I managed to enhance it. Now, I am facing an issue which I am not able to resolve.
One candidate record looks like
https://i.imgur.com/LAPAIbX.png
Since ML algorithms cannot work with categorical data, I want to encode this. My goal is to have a candidate record looking like this:
https://i.imgur.com/zzsiDzy.png
What I need to change is to add a new column for each possible value that exists in Knowledge1, Knowledge2, Knowledge3, Knowledge4, Tag1, and Tag2 of original data, but without repetition. I managed to encode it to get way more attributes than I need, which results in an inaccurate model. The way I tried gives me newly created attributes Jscript_Knowledge1, Jscript_Knowledge2, Jscript_Knowledge3 and so on, for each possible option.
If the explanation is not clear enough please let me know so that I could explain it further.
Thanks and any help is highly appreciated.
Cheers!
I have some understanding of your problem based on your explanation. I will try and elaborate how I would approach this problem. If that is not solving your problem, I may need more explanation to understand your problem. Lets get started.
For all the candidate data that you would have, collect a master
skill/knowledge list
This list becomes your columns
For each candidate, if he has this skill, the column becomes 1 for his record else it stays 0
This is the essence of one hot encoding, however, since same skill is scattered across multiple columns you are struggling with autoencoding it.
An alternative approach could be:
For each candidate collect all the knowledge skills as list and assign it into 1 column for knowledge and tags as another list and assign it to another column instead of current 4(Knowledge) + 2 (tags).
Sort the knowledge(and tag) list alphabetically within this column.
Auto One hot encoding after this may yield smaller columns than earlier
Hope this helps!
I've gotten close, I believe. My current query is this
items = Item.select("items.icon, items.name, item_types.name AS type, items.level, items.rarity, items.vendor_value")
.joins(:item_type)
.where("item_types.name = '#{params[:item_type]}'")
This gets me an array of Item objects that at least respond to :type with the item_type.name.
What I am looking for is an array of arrays that look so:
[icon, name, item_type.name, level, rarity, vendor_value]
I've already had it working fairly easily, but it is important to me that this be done in one fell swoop via sql, instead of creating a map afterwards, because there are times where I need to respond with 40k+ items and need this to be as fast as possible.
Not sure how to go from the above to an array of attributes, without performing a map.
Thanks for your help!
The pluck method does precisely what you want. In your case, it would look like this:
items = Item.joins(:item_type)
.where("item_types.name = ?", params[:item_type])
.pluck("items.icon", "items.name", "item_types.name AS type",
"items.level", "items.rarity", "items.vendor_value")
I also changed the where call to use parameterization instead of string interpolation—interpolation isn't recommended, especially when you're getting a value from the user.
Further reading:
Official documentation for pluck
An in-depth explanation of how to use pluck
In my Rails app, I will have an array with 1000 animal names. So, basically Strings. These names will never have any more data associated with them. I think making an animals table for them is overkill, because I use the Array only to sample an animal.
At the same time, I have REDIS in my project, and was thinking of just doing the following:
redis.set("animals", ["large", "array", "of", "animals", ...].to_json)
I'm not sure if that is problematic though and if I should worry that I'm storing a 1000 element array. I know there are HUGE data sets out there, but is 1000 anything worth worrying about?
Perhaps I should store them in a .txt file? One animal per line, so I would just use lines = File.foreach("animals"); lines.sample?
What is the best way to tackle this?
1000 rows is plenty for their own model/table. Databases have been used, abused, and refined for decades. Overkill is not really a concern unless you have a very good reason to suspect performance issues, which is unlikely, and even then, premature optimization is the root of all evil as they say. Keep you code clean and easily expandable. E.g., in animal.rb:
# return a random animal
def self.sample
offset(rand(count)).first
end
Whenever you need a sample (presumably in a controller) it's as simple as Animal.sample. And you might decide later that you want additional associations with those animals.
I want to populate a select menu with options from my database. There are many copies of the same entree, and because of that I get a drop down menu that have the same name again and again. I want to just get entries from my table so i have one of each possibility on it.
I have tried looking around for different ways to call information from the database, including that fact that Conditions can be applied to the call, unfortunately I must not have found the right one. also I found that
#products.uniq(:brand)
returned the full list, so I am probably using that wrong also. If I cannot do it in a single call, what would I need to do to get the same result.
I'm not sure I understand exactly the desired outcome. Are you looking for an array of values from the products.brand column where no entry is repeated? If so, you can do the following:
Product.uniq.pluck(:brand)
If you need to add extra conditions it's easy enough to do, you can just add a where(:foo => :bar) (but you need to add it before the pluck call).
I'm trying to figure out the best way to model a simple lookup in my rails app.
I have a model, Coupon, which can be of two "types", either Percent or Fixed Amount. I don't want to build a database table around the "type" lookup, so what I'd like to do is just have a coupon_type(integer) field on the Coupon table which can be either 1 (for Percent) or 2 (for Fixed).
What is the best way to handle this?
I found this: Ruby on Rails Static List Options for Drop Down Box but not sure how that would work when I want each value to have two fields, both ID and Description.
I'd like this to populate a select list as well.
Thank you for the feedback!
If this is really unlikely to change, or if it does change it will be an event significant enough to require redeployment, the easiest approach is to have a constant that defines the conditions:
COUPON_TYPES = {
:percent => 1,
:fixed => 2
}
COUPON_TYPES_FOR_SELECT = COUPON_TYPES.to_a
The first constant defines a forward mapping, the second in a format suitable for options_for_select.
It's important to note that this sort of thing would take, at most, a millisecond to read from a database. Unless you're rendering hundreds of forms per second it would hardly impact performance.
Don't worry about optimizing things that aren't perceptible problems.