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6 min readTo delete data from Firebase using Swift, follow these steps:Import the necessary Firebase libraries in your Swift file. import Firebase import FirebaseFirestore Get a reference to the Firebase Firestore database. let db = Firestore.firestore() Specify the document or collection that you want to delete. let docRef = db.collection("users").document("userID") // Replace "users" with your collection name and "userID" with the specific document ID you want to delete.
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7 min readThe Triple Exponential Average (TRIX) is a technical indicator used in technical analysis to identify and confirm trends in the price movements of financial assets such as stocks, currencies, or commodities. It attempts to smooth out the price data and provide a clearer picture of the underlying trend.TRIX is calculated using multiple exponential moving averages (EMAs) of the asset's price. Firstly, a single EMA is calculated for the asset's price.
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5 min readIn Swift, tuples are immutable, meaning their values cannot be changed once they are created. However, if you want to update a tuples array, you can reassign a modified tuple to the specific index in the array.
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7 min readTo create a many-to-many association using grdb in Swift, you can follow these steps:Define the tables: Start by defining the two tables you want to associate. Let's say we have a "User" table and a "Role" table. struct User: TableRecord { static let roleUsers = hasMany(RoleUser.self) } struct Role: TableRecord { static let roleUsers = hasMany(RoleUser.self) } struct RoleUser: TableRecord { static let role = belongsTo(Role.
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10 min readKeltner Channels are a technical indicator used in trading to identify potential buy or sell signals. They are derived from the Average True Range (ATR) and plotted above and below a moving average line. Keltner Channels are often used by scalpers, who aim to profit from small price movements within a short period of time.The Keltner Channels consist of three lines on a price chart: an upper band, a lower band, and a centerline.
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8 min readIn Swift, decoding nested JSON data involves several steps. Here's a step-by-step guide on how to decode nested JSON in Swift:Define a struct or class that represents the structure of your JSON data.Ensure that your struct or class conforms to the Codable protocol. This allows Swift's JSONDecoder to convert JSON data into instances of your custom type.Identify the nested JSON objects or arrays within your JSON data.
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9 min readThe Arms Index, also known as TRIN (short for Trading Index), is a technical indicator used by traders and investors to gauge the overall market sentiment or the strength of a particular market trend. It was developed by Richard Arms, Jr. in the 1960s.The Arms Index is calculated by dividing the number of advancing (or up) stocks by the number of declining (or down) stocks, and then dividing this ratio by the advancing (or up) volume divided by the declining (or down) volume.
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5 min readDecoding bytes to a string in Swift can be achieved using the String initializer or the String(decoding:as:) method. Here's how it can be done:Using the String initializer: let bytes: [UInt8] = [104, 101, 108, 108, 111] // Example byte array if let decodedString = String(bytes: bytes, encoding: .
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7 min readTo upload an image with a parameter multipart in Swift, you can follow these steps:Create a URLSession and URLRequest to handle the HTTP request: let url = URL(string: "your_upload_url") var request = URLRequest(url: url!) request.httpMethod = "POST" Set the Content-Type header to indicate multipart form data: request.
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9 min readThe Elder-Ray Index is a technical analysis tool developed by Dr. Alexander Elder. It aims to measure buying and selling pressure in a given market by analyzing the relationship between the price and the bulls' and bears' power. This index consists of two components: the Bulls Power and the Bears Power.Bulls Power: This component calculates the difference between the high price and an Exponential Moving Average (EMA) of prices. It represents the strength of the bulls in the market.
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8 min readTo use Swift's async/await in parallel, you can follow these steps:Import the necessary modules: Ensure that you have imported the required modules like Dispatch, AsyncHTTPClient, or any other relevant ones. Define the async functions: Create the necessary async functions that perform the parallel tasks. These functions should have the async keyword before the function definition.