I have a last year retail sales data. Now I'm interested to build a recommender system based on the last year sales data.
Customer A bought product Ids 1,2,3,4
Customer B bought products ids 2,3,5
Customer C bought product ids 6,2,7,3
In the above data set all the customers bought product Id 3 when they purchase product id 2
So which Machine learning method I have to use create a recommender system.
Note : I'm gonna build tensorflow lite model by using python and keras
Look for the apriori algorithm or any other which can generate association rules.
Related
I have decent Google-Fu skills, but they've utterly failed me on this.
I'm working in PowerPivot and I'm trying to match up a product with a price point in another table. Sounds easy, right? Well each product has several price points, based on the source of the price, with a hierarchy of importance.
For Example:
Product 1 has three prices living in a Pricing Ledger:
Price 1 has an account # of A22011
Price 2 has an account # of B22011
Price 3 has an account # of C22011
Price A overrides Price B which overrides Price C
What I want to do is be able to pull the most relevant price (i.e, that with the highest rank in the hierarchy) when not all price points are being used.
I'd originally used a series of IF statements, but that's when there were only four points. We now have ten points, and that might grow, so the IF statements are an untenable solution.
I'd appreciate any help.
-Thanks-
I would like to use the odoo POS also for internal use. Employees should be able to buy products for themselves. All of the costs should be charged via the payslip of every employee.
Example: A is an employee of my company X. A buys a coke (2$) from the POS. B is chief of HR at X and wants to generate the payslip of A to send him his loan (100$) for the month. Odoo should now calculate and sum up all POS expenses and then show B that A gets a loan of 98$.
I would probably do some adjustments with custom modules, however would it even be possible to set an employee as the customer in odoo?
I created 3 chart of accounts as follow with type current asset:
23600 Stock Interim Account (Received)
14600 Stock Interim Account (Delivered)
14000 Stock Valuation Account
And assigned to product category.
Set costing method as Average and inventory valuation as Perpetual.
Created a purchase order and received products
Then system created journal entries as follow.
When i create an vendor invoice from same purchase order, in product lines it automatically choose 501100 Cost of Goods Sold in Trading instead of 23600 Stock Interim Account (Received).
Did i configure anything wrong?
How can i resolve this?
The task here is to define the optimal (as detailed below) way of ordering items (parts) from suppliers.
The relevant parts of the table schema (with some sample data) are
Items
ID NUMBER
1 Item0001
2 Item0002
3 Item0003
Suppliers
ID NAME DELIVERY DISCOUNT
1 Supplier0001 0 0
2 Supplier0002 0 0.025
3 Supplier0003 20 0
DELIVERY is the delivery charge (in dollars) levied by that supplier on each delivery. DISCOUNT is the settlement discount (as a percentage i.e. 2.5% for ID=2 above) allowed by that supplier for on time payment.
SupplierItems
SUPPLIER_ID ITEM_ID PRICE
1 2 21.67
1 5 45.54
1 7 32.97
This is the many-to-many join between suppliers and items with the price that supplier charges for that item (in dollars). Every item has at least 1 supplier but some have more than one. A supplier may have no items.
PartsRequests
ID ITEM_ID QUANTITY LOCATION_ID ORDER_ID
1 59 4 2 (null)
2 89 5 2 (null)
3 42 4 2 (null)
This table is a request from a field site for parts to be ordered and delivered by the supplier to that site. A delivery of any number of items to a site attracts a delivery charge. When the parts are ordered, the ORDER_ID is inserted into the table so we are only concerned with those where ORDER_ID IS NULL
The question is, what is the optimal way to order these parts for each `LOCATION' where there are 3 optimal solutions that need to be presented to the user for selection.
The combination of orders with the least number of suppliers
The combination of orders with the lowest total cost i.e. The sum of QUANTITY*PRICE for each item plus the DELIVERY for each order summed over all orders ignoring DISCOUNT
As item 2 but accounting for DISCOUNT
Clearly I need to determine the combinations of orders that are available and then determining the optimal ones becomes trivial but I am a bit stuck on an efficient way to deal with building the combinations.
I have built some SQL fiddles in SQL Server 2008 with random data. This one has 100 items, 10 suppliers and 100 requests. This one has 1000 items, 50 suppliers and 250 requests. The table schema is the same.
Update
I reasoned that the solution had to be recursive and I built a nice table valued function to get but I ran into the 32 hard limit on recursion in SQL Server. I was uncomfortable with it anyway because it hinted more of a procedural language solution than a RDMS.
So I am now playing with CTE recursion.
The root query is:
SELECT DISTINCT
'' SOLUTION_ID
,LOCATION_ID
,SUPPLIER_ID
,(subquery I haven't quite worked out) SOLE_SUPPLIER
FROM PartsRequests pr
INNER JOIN
SupplierItems si ON pr.ITEM_ID=si.ITEM_ID
WHERE pr.ORDER_ID IS NULL
This gets all the suppliers that can supply the required items and is certainly a solution, probably not optimal. The subquery sets a flag if the supplier is the sole supplier of any product required for that location; if so they must be part of any solution.
The recursive part is to remove suppliers one by one by means of CTE.SUPPLIER_ID<>CTE.SUPPLIER_ID and add them if they still cover all the items. The SOLUTION_ID will be a CSV list of the suppliers removed, partly to uniquely identify each solution and partly to check against so I get combinations instead of permutations.
Still working on the details, the purpose of this update was to allow the Community to say "Yay, looks like that will work" or, alternatively "You moron, that won't work because ..."
Thanks
This is a more general answer (as in, not sql) as I think solving this problem will require something more powerful. Your first scenario is to select a minimum number of suppliers. This problem can be seen as a set cover problem as you are trying to cover all demands per site with the suppliers. This problem is already NP-complete.
Your third scenario seems to be basically the same as the second. You just have to take the discount into account in the prices, assuming you pay on time for every order.
The second scenario is at least NP-hard as I see a lot of resemblance with the facility location problem. You are trying to decide which suppliers (facilities) to use (open) to cover your orders (demands) based on their prices and delivery costs (opening costs).
Enumerating your possible solutions seems infeasible as with 10 suppliers, you have 2^10 possibilities of using them, further complicated by the distribution of demands internally.
I would suggest some dynamic programming to first select the suppliers that you have to use (=they are the only ones that deliver a specific thing), eliminating some possibilities (if the cost for supplier A +delivery cost A< cost for supplier B) and then trying to expand your set of possible solutions. Linear programming is also a valid train of thought.
Situation looks like this:
We have product 'A123' and we have to remember lowest price for it.
Prices for one product comes from random number of shops and there is no way to tell when shop x will send us their price for 'A123'.
So I had SQL table with columns:
product_number
price
shop (from which shop this price comes)
An SQL function for updating product price looks like this (this is SQL pseudo-code, syntax doesn't matter):
function update_product(in_shop, in_product_number, in_price)
select price, shop into productRow from products where product_number = in_product_number;
if found then
if (productRow.price > in_price) or (productRow.price < in_price and productRow.shop = in_shop) then
update row with new price and new shop
end if;
else
insert new product that we didn't have before
end if;
the (productRow.price < in_price and productRow.shop = in_shop) condition is to prevent situation like this:
In products table we have
A123 22.5 amazon
then comes info from amazon again:
A123 25 amazon
Thanks to above condition we update price to higher which is correct behavior.
But algorithm fails in this situation: again we have a row in the products table:
A123 22.5 amazon
then comes info from merlin
A123 23 merlin (we don't update because price is higher)
then comes info from amazon
A123 35 amazon
and we update table and now we have:
A123 35 amazon
but this is wrong because merlin earlier has lower price for that product.
Any idea how to avoid this situation?
The only way you are going to solve your problem is keep track of the price per shop and then only return the lowest current price. So for example you would need a table like the one you already have, but when you select out of the table something like:
select min(price)
from products
where product_number = :my_product
Personally if it were me, I would keep a time stamp of when you receive the product price updates so you would be able to ascertain when you got the update.
To make this work you should maintain a table that contains the following:
Product
Supplier
LatestPrice
Then identify the current best supplier by querying that table - you can either do this when requested or when the table is updated either way you simplify the problem at the price of slightly more complex schema and queries
Additional (following comment):
Ok, this is going to mean that you need to store more data - but you don't have a huge amount of choice - the data is required to solve the problem so you either: a) have to update prices from all suppliers concurrently and then choose the best price from that snapshot or b) store the prices as you get them and pick the best price from the data you've got. The former implies a fairly hefty overhead in terms of fetching and processing data whereas the latter is basically a fairly modest storage problem and something any decent databases will cope with easily.
Basically, the problem is that you only store the lowest price from 1 vendor. You have to keep records of prices of all vendors, and use a selection query to select the minimum.
For example, If you have:
A123 22.5 Amazon
and you got:
A123 23 Merlin
You have to insert it, even if it is with higher price, because it's a different vendor. So you'll have:
A123 22.5 Amazon
A123 23 Merlin
When you get the new price from Amazon, for example: 25, you just update it. So you'll get:
A123 25 Amazon
A123 23 Merlin
then select the lowest price, Merlin, in this case.