更新 CoreML model 时 MLUpdateContext 为空

Question

My problem is the following - In the method below the variable finalContext seem to not contain anything. I get error message: Error: The operation couldn't be completed. (Foundation._GenericObjCError error 0.) Error: The operation couldn't be completed. (Foundation._GenericObjCError error 0.) when calling the function. I need help how to debug this issue or what could be the possible cause for this. EDIT - finalContext does not contain the model that I am trying to access.

func updateModel(){
    //Configuration for when update is performed
    let modelConfig = MLModelConfiguration()
    modelConfig.computeUnits = .cpuAndGPU
    let fileManager = FileManager.default
    //Image batch for updating the model
    //Might need to change from a batch to a single image
    let updateImages: [UIImage] = [theImage!]
    let imageBatch = createTrainingData(imageArray: updateImages, outputLabel: "dog") // temp outputLabel
    do {
        let updateTask = try MLUpdateTask(forModelAt: globalCompiledModel!, trainingData: imageBatch, configuration: modelConfig,
                         progressHandlers: MLUpdateProgressHandlers(forEvents: [.trainingBegin,.epochEnd],
                          progressHandler: { (contextProgress) in
                            print(contextProgress.event)
                            // you can check the progress here, after each epoch
                         }) { (finalContext) in
                                do {
                                    // Save the updated model to temporary filename.
                                    let documentDirectory = try fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor:nil, create:true)
                                    let fileURL = documentDirectory.appendingPathComponent("CatDog.mlmodelc")
                                    print("Updated temp model URL: \(fileURL)")
                                    try finalContext.model.write(to: fileURL)
                                } catch(let error) {
                                    print("Error: \(error.localizedDescription)")
                                }
        })
        updateTask.resume()
    } catch {
        print("Error while updating: \(error.localizedDescription)")
    }
}

Answer 1

I found the issue here. MLArrayBatchProvider was not properly configured by me so the updateTask was not properly completed.

Answer 2

Es domaj, ka vajag panemt iepist al un paprovet velreiz

Answer 3

For me the issue was resolved by abandoning using a UpdatableTrainingInput class that conformed to id<MLFeatureProvider>, but instead creating a MLDictionaryFeatureProvider as shown here: https://developer.apple.com/documentation/coreml/model_personalization/personalizing_a_model_with_on-device_updates?language=objc