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1. Top results related to define many to one function

   • many to one mapping Hash Function

     Top Answer

     Answered Dec 29, 2011 · 2 votes

     what i was looking for is : Bloom Filter

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     1/5

   • Many to one and many to many LSTM examples in Keras

     Top Answer

     Answered Nov 09, 2020 · 181 votes

     So:

     model.add(Dense(output_size, input_shape=input_shape))-

     model.add(RepeatVector(number_of_times, input_shape=input_shape))model.add(LSTM(output_size, return_sequences=True))

     model = Sequential()model.add(LSTM(1, input_shape=(timesteps, data_dim)))

     model = Sequential()model.add(LSTM(1, input_shape=(timesteps, data_dim), return_sequences=True))

     • One-to-one: you could use a Dense layer as you are not processing sequences: model.add(Dense(output_size, input_shape=input_shape))
     • One-to-many: this option is not supported well as chaining models is not very easy in Keras , so the following version is the easiest one: model.add(RepeatVector(number_of_times, input_shape=input_shape))model.add(LSTM(output_size, return_sequences=True))
     • Many-to-one: actually, your code snippet is (almost) an example of this approach: model = Sequential()model.add(LSTM(1, input_shape=(timesteps, data_dim)))
     • Many-to-many: This is the easiest snippet when the length of the input and output matches the number of recurrent steps: model = Sequential()model.add(LSTM(1, input_shape=(timesteps, data_dim), return_sequences=True))
     • Many-to-many when number of steps differ from input/output length: this is freaky hard in Keras. There are no easy code snippets to code that.

     EDIT: Ad 5

     In one of my recent applications, we implemented something which might be similar to many-to-many from the 4th image. In case you want to have a network with the following architecture (when an input is longer than the output):

     O O O | | | O O O O O O | | | | | | O O O O O O

     You could achieve this in the following manner:

     model = Sequential()model.add(LSTM(1, input_shape=(timesteps, data_dim), return_sequences=True))model.add(Lambda(lambda x: x[:, -N:, :])) #Select last N from output

     Where N is the number of last steps you want to cover (on image N = 3).

     From this point getting to:

     O O O | | | O O O O O O | | | O O O

     is as simple as artificial padding sequence of length N using e.g. with 0 vectors, in order to adjust it to an appropriate size.

     Check all answers on Stack Overflow

     2/5

   • One-to-Many-to-One with attributes Form with Symfony 3 / Doctrine

     Top Answer

     Answered Aug 01, 2018 · 9 votes

     You have come accross one of the hardest problems with Symfony forms. Fortunately, there is some good documentation. Let me summarize the important steps.

     You’re right: The entity Person needs to know about its relationship with PersonJob if you want to manipulate that relationship from a Person’s point of view. So you need to add a property:

     // src/AppBundle/Entity/Person.php/** * @ORM\OneToMany(targetEntity="PersonJob", mappedBy="person") */private $personJobs;public function __construct(){ $this->personJobs = new \Doctrine\Common\Collections\ArrayCollection();}

     and then you will have in the form type

     // src/AppBundle/Form/PersonType.php$builder ->add('name') ->add('firstname') ->add('personJobs', CollectionType::class, array( 'entry_type' => PersonJobType::class, 'allow_add' => true, );

     Note the type of the personJobs field. Since a person can have many PersonJobs, you need a form type that can handle collections. This is the purpose of the built-in CollectionType (check out its documentation!). You also need the form type PersonJobType, so that CollectionType knows how to build the sub-forms:

     class PersonJobType extends AbstractType{ public function buildForm(FormBuilderInterface $builder, array $options) { $builder ->add('comment') ->add('datestart', DateTimeType::class) ->add('dateend', DateTimeType::class) ->add('job') // requires Job::__toString() to be defined! ; } public function configureOptions(OptionsResolver $resolver) { $resolver->setDefaults(array( 'data_class' => 'AppBundle\Entity\PersonJob' )); }}

     For debugging purposes, change your controller to

     public function testAction() { $person = new Person(); $form = $this->createForm(PersonType::class, $person); $form->add('submit', SubmitType::class); $form->handleRequest($request); if ($form->isSubmitted() && $form->isValid()) { print '<pre>'; var_dump($form->getData()); die(); } return $this->render('default/index.html.twig', [ 'form' => $form->createView(), ]);}

     Now go ahead and copy & paste the Twig and Javascript code from Adding and Removing Items (you have to make minor changes such as replacing form.emails with form.personJobs).

     The form

     The form will look like

     Just the Person form with a “Add another PersonJob” link:

     Adding a PersonJob:

     Adding anothing PersonJob:

     The data received

     Submit the form and see the output of var_dump:

     object(AppBundle\Entity\Person)#247 (5) { ["id":"AppBundle\Entity\Person":private]=> NULL ["name":"AppBundle\Entity\Person":private]=> string(12) "Charles Dude" ["firstName":"AppBundle\Entity\Person":private]=> string(7) "Charles" ["active":"AppBundle\Entity\Person":private]=> bool(true) ["personJobs":"AppBundle\Entity\Person":private]=> object(Doctrine\Common\Collections\ArrayCollection)#248 (1) { ["elements":"Doctrine\Common\Collections\ArrayCollection":private]=> array(2) { [0]=> object(AppBundle\Entity\PersonJob)#962 (6) { ["id":"AppBundle\Entity\PersonJob":private]=> NULL ["comment":"AppBundle\Entity\PersonJob":private]=> string(19) "Something important" ["datestart":"AppBundle\Entity\PersonJob":private]=> object(DateTime)#1088 (3) { … } ["dateend": …] => … ["person":"AppBundle\Entity\PersonJob":private]=> NULL ["job":"AppBundle\Entity\PersonJob":private]=> object(AppBundle\Entity\Job)#1171 (2) { ["id":"AppBundle\Entity\Job":private]=> int(2) ["name":"AppBundle\Entity\Job":private]=> string(5) "Job 2" } } [1]=> … }}

     Two things remain to be done:

     • Set the person property of the nested PersonJob entities properly to the new (but not yet persisted) Person.
     • Tell Doctrine about the new PersonJob entities by calling $em->persist(…) on them.

     Relevant documentation:

     • CollectionType Field
     • How to Embed a Collection of Forms

     Check all answers on Stack Overflow

     3/5

   • One to One or Many to One in sequelize?

     Top Answer

     Answered Jul 02, 2018 · 0 votes

     You should use hasOne() method. not belongsTo() that's it :)

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     4/5

   • How can we define one-to-one, one-to-many, many-to-one, and many-to-many LSTM neural networks in Keras?

     Top Answer

     Answered Sep 02, 2018 · 11 votes

     The distinction one-to-one, one-to-many, many-to-one, many-to-many is only existent in case of RNN / LSTM or networks that work on sequential ( temporal ) data, CNNs work on spatial data there this distinction does not exist. So many always involves multiple timesteps / a sequence

     The different species describe the shape of input and output and its classification. For the input one means a single input quantity is classified as a closed quantity and many means a sequence of quantities ( i.e. sequence of images, sequence of words) is classified as a closed quantity. For the output one means the output is a scalar ( binary classification i.e. is a bird or is not a bird ) 0 or 1, many means output is a one-hot encoded vector with one dimension for each class ( multiclass classification i.e. is a sparrow, is a robin, ... ), for i.e. three classes 001, 010, 100 :

     In the following example images and sequences of images are used as quantity that shall be classified, alternatively you could use words or ... and sequences of words ( sentences ) or ... :

     one-to-one : single images ( or words,... ) are classified in single class ( binary classification ) i.e. is this a bird or not

     one-to-many : single images ( or words,... ) are classified in multiple classes

     many-to-one : sequence of images ( or words, ... ) is classified in single class ( binary classification of a sequence )

     many-to-many : sequence of images ( or words, ... ) is classified in multiple classes

     cf https://www.quora.com/How-can-I-choose-between-one-to-one-one-to-many-many-to-one-many-to-one-and-many-to-many-in-long-short-term-memory-LSTM

     one-to-one ( activation=sigmoid ( default ) loss=mean_squared_error )

     from keras.models import Sequentialfrom keras.layers import Densefrom keras.layers import LSTM# prepare sequencelength = 5seq = array([i/float(length) for i in range(length)])X = seq.reshape(len(seq), 1, 1)y = seq.reshape(len(seq), 1)# define LSTM configurationn_neurons = lengthn_batch = lengthn_epoch = 1000# create LSTMmodel = Sequential()model.add(LSTM(n_neurons, input_shape=(1, 1)))model.add(Dense(1))model.compile(loss='mean_squared_error', optimizer='adam')print(model.summary())# train LSTMmodel.fit(X, y, epochs=n_epoch, batch_size=n_batch, verbose=2)# evaluateresult = model.predict(X, batch_size=n_batch, verbose=0)for value in result: print('%.1f' % value)

     source : https://machinelearningmastery.com/timedistributed-layer-for-long-short-term-memory-networks-in-python/

     one-to-many uses RepeatVector() to transform single quantities into a sequence what is needed for multiclass classification

     def test_one_to_many(self): params = dict( input_dims=[1, 10], activation='tanh', return_sequences=False, output_dim=3 ), number_of_times = 4 model = Sequential() model.add(RepeatVector(number_of_times, input_shape=(10,))) model.add(LSTM(output_dim=params[0]['output_dim'], activation=params[0]['activation'], inner_activation='sigmoid', return_sequences=True, )) relative_error, keras_preds, coreml_preds = simple_model_eval(params, model) # print relative_error, '\n', keras_preds, '\n', coreml_preds, '\n' for i in range(len(relative_error)): self.assertLessEqual(relative_error[i], 0.01)

     source: https://www.programcreek.com/python/example/89689/keras.layers.RepeatVector

     alternative one-to-many

     model.add(RepeatVector(number_of_times, input_shape=input_shape))model.add(LSTM(output_size, return_sequences=True))

     source : Many to one and many to many LSTM examples in Keras

     many-to-one, binary classification (loss=binary_crossentropy, activation=sigmoid, dimensionality of fully-connected ouput layer is 1 (Dense(1)), outputs a scalar, 0 or 1 )

     model = Sequential()model.add(Embedding(5000, 32, input_length=500))model.add(LSTM(100, dropout=0.2, recurrent_dropout=0.2))model.add(Dense(1, activation='sigmoid'))model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy']) print(model.summary())model.fit(X_train, y_train, epochs=3, batch_size=64)# Final evaluation of the modelscores = model.evaluate(X_test, y_test, verbose=0)

     many-to-many, multiclass classification ( loss=sparse_categorial_crossentropy , activation=softmax, needs one-hot encoding of target, ground truth data, dimensionality of fully-connected ouput layer is 7 (Dense71)) outputs a 7-dimensional vector in that the 7 classes are one-hot encoded )

     from keras.models import Sequentialfrom keras.layers import *model = Sequential()model.add(Embedding(5000, 32, input_length=500))model.add(LSTM(100, dropout=0.2, recurrent_dropout=0.2))model.add(Dense(7, activation='softmax'))model.compile(loss='sparse_categorical_crossentropy', optimizer='adam', metrics=['accuracy'])model.summary()

     cf Keras LSTM multiclass classification

     Alternative many-to-many using TimeDistributed layer cf https://machinelearningmastery.com/timedistributed-layer-for-long-short-term-memory-networks-in-python/ for description

     from keras.models import Sequentialfrom keras.layers import Densefrom keras.layers import TimeDistributedfrom keras.layers import LSTM# prepare sequencelength = 5seq = array([i/float(length) for i in range(length)])X = seq.reshape(1, length, 1)y = seq.reshape(1, length, 1)# define LSTM configurationn_neurons = lengthn_batch = 1n_epoch = 1000# create LSTMmodel = Sequential()model.add(LSTM(n_neurons, input_shape=(length, 1), return_sequences=True))model.add(TimeDistributed(Dense(1)))model.compile(loss='mean_squared_error', optimizer='adam')print(model.summary())# train LSTMmodel.fit(X, y, epochs=n_epoch, batch_size=n_batch, verbose=2)# evaluateresult = model.predict(X, batch_size=n_batch, verbose=0)for value in result[0,:,0]: print('%.1f' % value)

     source : https://machinelearningmastery.com/timedistributed-layer-for-long-short-term-memory-networks-in-python/

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     5/5

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2. www.geeksforgeeks.org › many-one-functionsMany One Functions: Definition, Formula, Properties, Examples

   www.geeksforgeeks.org › many-one-functions

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   Dec 26, 2023 · Many-one or many-to-one function is a type of function that maps two or more elements of the domain set with a single element in the range set. In this article, we will discuss all the relevant concepts of many-one functions such that definition, examples, & properties.

3. www.geeksforgeeks.org › types-of-functionsTypes of Functions: Classification, One-One, Onto, and Examples

   www.geeksforgeeks.org › types-of-functions

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   • What Is A function?
   • Types of Functions in Maths
   • One to One (Injective) Function
   • Many to One Function
   • Onto (Surjective) Function
   • Into Function
   • Summary: Types of Functions
   • Solved Examples on Types of Function

   A functionis a relation between two sets set A and set B. Such that every element of set A has an image in set B and no element in set A has more than one image in set B. Let A and B be two nonempty sets. A function or mapping ffrom A to B is written as f: A → B is a rule by which each element a ∈ A is associated with a unique elementb ∈ B.

   See full list on geeksforgeeks.org

   An example of a simple function is f(x) = x3. In this function, f(x) takes the value of “x” and then cubes it to find the value of the function. For example, if the value of x is taken to be 2, then the function gives 8 as output i.e. f(2) = 8. Some other examples of functions are: There are several types of functions in maths. Some of the importan...

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   A function f: X → Y is said to be a one-to-one function if the images of distinct elements of X under f are distinct. Thus, f is one to one if f(x1) = f(x2) Property: A function f: A → B is one-to-one if f(x1) = f(x2) implies x1= x2, i.e, an image of a distinct element of Aunderfmapping (function) is distinct. Condition to be One-to-One function: E...

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   If the function is not one to one function, then it should be many to one function means every element of the domain has more than one image at codomain after mapping. 1. Property:One or more elements having the same image in the codomain 2. Condition to be Many to One function: One or more than one element in the domain having a single image in th...

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   A function f: X → Y is said to be an onto function if every element of Y is an image of some element of set X under f, i.e for every y ∈ Y there exists an element x in X such that f(x) = y. Condition to be onto function: The range of function should be equal to the codomain. As we see in the above two images, the range is equal to the codomain mean...

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   A function f: X → Yis said to be an into a function if there exists at least one element or more than one element in Y, which does not have any pre-images in X, which simply means that every element of the codomain are not mapped with elements of the domain. From the above image, we can clearly see that every element of the codomain is not mapped w...

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   All types can be summarized in the following table: Read More, 1. Domain and Range of Trigonometric Functions 2. Range of a Function 3. Relations and Functions 4. Composition of Functions 5. Hyperbolic Function

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   Example 1: Check whether the function f(x) = 2x + 3, is one-to-one or not if Domain = {1, 2, 1/2} and Codomain = {5, 7, 4} Solution: Example 2: Check whether the function is one-to-one or not: f(x) = 3x – 2 Solution: Example 3: Check whether the function is one-to-one or not: f(x) = x2+ 3. Solution: Example 4: If N: → N, f(x) = 2x + 1 then check wh...

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4. testbook.com › maths › many-one-functionMany One Function: Definition, Properties and Solved Examples

   testbook.com › maths › many-one-function

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   May 4, 2023 · Many One Function is a special relation between two sets where the elements of the domain set have more than one image in the range set. In this function, for an input of single value we get more than one result. It is mathematically defined using sets and it is represented with the help of mapping.

5. www.toppr.com › types-of-functionsTypes of Functions: Classification, One-One, Onto ... - Toppr

   www.toppr.com › types-of-functions

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   Many to One Function. It is a function which maps two or more elements of A to the same element of set B. Two or more elements of A have the same image in B. Onto Function. If there exists a function for which every element of set B there is (are) pre-image (s) in set A, it is Onto Function. Onto is also referred as Surjective Function.

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6. www.cuemath.com › algebra › types-of-functionsTypes of Functions - Types, Graphs, Examples - Cuemath

   www.cuemath.com › algebra › types-of-functions

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   Many to One Function. A many to one function is defined by the function f: A → B, such that more than one element of the set A are connected to the same element in the set B. In a many to one function, more than one element has the same image.

7. www.ck12.org › what-is-a-many-one-functionWhat is a Many-One Function? - Definition | CK-12 Foundation

   www.ck12.org › what-is-a-many-one-function

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   A Many-One function is a type of function in which different elements of the domain (input) may map to the same element of the co-domain (output). In other words, two or more inputs may have the same output. Mathematically, a function f: A → B is said to be many-one if there exist x 1, x 2 ∈ A such that x 1 ≠ x 2 and f ( x 1) = f ( x 2).

8. People also ask

   What is many to one function?

   • Many to One function is one of the Types of function, also known as many one function, is where one or more elements of set A are related to only one element of Set B. In other word, in any domain for any function, if two or more input is related to one single output, that relation is defined as many to one function.

   Many One Functions: Definition, Formula, Properties, Examples

   www.geeksforgeeks.org/many-one-functions/

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   What are the properties of many one function?

   • The properties of Many One Function are listed below. Domain set of this function should have at least two elements equal to the codomain value. The number of elements in the domain set must be one more than the number of elements in the codomain set. The codomain set is always less than the range value.

   Many One Function: Definition, Properties and Solved Examples

   testbook.com/maths/many-one-function

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   What is a many-one function?

   • Many-one or many-to-one function is a type of function that maps two or more elements of the domain set with a single element in the range set. In this article, we will discuss all the relevant concepts of many-one functions such that definition, examples, & properties.

   Many One Functions: Definition, Formula, Properties, Examples

   www.geeksforgeeks.org/many-one-functions/

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   How do you know if a function is a many one function?

   • A function f : A → B f : A → B is said to be a many one function if different elements of the domain set A have the same images in the codomain set B. In other words, if the same element in the codomain set has different preimages in the domain set then that function is known as many one function.

   Many One Function: Definition, Properties and Solved Examples

   testbook.com/maths/many-one-function

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9. www.khanacademy.org › math › linear-algebraSurjective (onto) and injective (one-to-one) functions

   www.khanacademy.org › math › linear-algebra

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   one to one function: "for every y in Y that the function maps to, only one x maps to it". (injective - there are as many points f(x) as there are x's in the domain). onto function: "every y in Y is f(x) for some x in X. (surjective - f "covers" Y)

   • Video Duration: 10 min

   • Author: Sal Khan