simple-neural-network | simple Python script showing how the backpropagation | Machine Learning library
kandi X-RAY | simple-neural-network Summary
kandi X-RAY | simple-neural-network Summary
A simple Python script showing how the backpropagation algorithm works.
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Top functions reviewed by kandi - BETA
- Train the model
- Feed forward computation
- Calculate the PD error wrt output
- Calculates the total net input
- Calculate the weight of a given index
- Calculates the total error of each training set
- Calculate the error
- Calculate the outputs of each neuron
- Calculate the output
- Squared squash
simple-neural-network Key Features
simple-neural-network Examples and Code Snippets
from tensorflow.keras.models import Sequential
model = Sequential()
from tensorflow.keras.layers import Dense
model.add(Dense(units=64, activation='relu'))
model.add(Dense(units=10, activation='softmax'))
model.compile(loss='categorical_crossen
def predict(params, input_vec):
assert input_vec.ndim == 1
activations = input_vec
for W, b in params:
outputs = jnp.dot(W, activations) + b # `activations` on the right-hand side!
activations = jnp.tanh(outputs) # inputs to the
Community Discussions
Trending Discussions on simple-neural-network
QUESTION
I have trained a simple NN by modifying the following code
https://www.kaggle.com/ancientaxe/simple-neural-network-from-scratch-in-python
I would now like to test it on another sample dataset. how should i proceed with it ?
...ANSWER
Answered 2020-Aug-25 at 11:10I see you use a model from scratch. In this case, you should run this code, as indicated in the notebook, after setting your X
and y
for your new test set. For more information, see the the notebook as I did not put here everything:
QUESTION
I am trying to learn the correct procedure for training a neural network for classification. Many tutorials are there but they never explain how to report for the generalization performance. Can somebody please tell me if the following is the correct method or not. I am using first 100 examples from the fisheriris data set that has labels 1,2 and call them as X
and Y
respectively. Then I split X
into trainData
and Xtest
with a 90/10 split ratio. Using trainData
I trained the NN model. Now the NN internally further splits trainData
into tr,val,test subsets. My confusion is which one is usually used for generalization purpose when reporting the performance of the model to unseen data in conferences/Journals?
The dataset can be found in the link: https://www.mathworks.com/matlabcentral/fileexchange/71468-simple-neural-networks-with-k-fold-cross-validation-manner
ANSWER
Answered 2020-Jan-27 at 08:33There are a few issues with the code. Let's deal with them before answering your question. First, you set a threshold of 0.5 for making decisions (Yhat_train = (train_predict >= 0.5);
) while all points of your net prediction are above 0.5. This means you only get zeros in your confusion matrices. You can plot the scores to choose a better threshold:
QUESTION
I'm trying to get into ML and Deep Learning. It's been educational for me to start out with this in Python rather than a different language where I would may lose focus of exactly what is really going on. I've looked across the internet for tutorials on Neural Networks in Python and TensorFlow seems to be dominating the field, is this true? I enjoy doing things on my own (pure language) but I haven't seen a lot of tutorials that teach this that don't involve TensorFlow or some other library (Keras, Scikit-learn, etc.); so now I've decided to look into these.
The question I have is: does TensorFlow take away from pure Python?
For example, this code is from a tutorial and it creates a simple neural net that predicts what the output will be based on three numbers (NOTE: I haven't checked how this code trains and could probably make this better if I did I were to make it again myself):
...ANSWER
Answered 2019-Dec-17 at 19:37For anyone reading this I am going to share my thoughts. I chose to take the route of pure python with nothing like TensorFlow. I heard from other people that TensorFlow could take away an understanding that beginners need. At first, it was really hard for me to find anything that could help, but then I found everything all at once. The following links are the resources I used.
Theory:
The first 2-4 videos of this series by 3blue1brown: https://www.youtube.com/watch?v=WUvTyaaNkzM&list=PLZHQObOWTQDMsr9K-rj53DwVRMYO3t5Yr
All of the videos in this series by 3blue1brown: https://www.youtube.com/watch?v=aircAruvnKk&list=PLZHQObOWTQDNU6R1_67000Dx_ZCJB-3pi
Implementation:
This video by the coding train: https://www.youtube.com/watch?v=jc2IthslyzM&list=PLRqwX-V7Uu6bCN8LKrcMa6zF4FPtXyXYj&index=8
Additional links for the calculus are: https://www.symbolab.com/cheat-sheets/Derivatives#, https://www.mathsisfun.com/calculus/derivatives-partial.html
And this entire series by the coding train: https://www.youtube.com/watch?v=XJ7HLz9VYz0&list=PLRqwX-V7Uu6Y7MdSCaIfsxc561QI0U0Tb
Summary
And that is it, that is all I really needed to get started it is awesome! One more thing I should note is that I eventually ended up using Processing.py, if you don't know what it is, it is not a library for neural networks, but instead allows for really easy graphics in python, there are functions like ellipse
which just make a circle, this is the python implementation of what the coding train uses.
QUESTION
I'm currently working on a project where uTensor is required. uTensor seems to work correctly, however I ran into an issue which I (apparently) cannot fix myself.
Problem definitionI've created a simple python script which generates and saves a model to a file. This saved model can later be converted into C++ code by using uTensor-cli. The generated C++ code will be ran on a ARM dev board.
Everything runs fine, no errors. However, when I create a model like: "xW+b" the output of the model on the devboard always equals some static value, which is not equal to the output of the model from the python script.
The thing is, when a simple model like "W+b" is used (no input tensor used here) the output on the ARM devboard equals the output of the python script. And everything works as expected.
My findingsWhen using an input tensor (nothing large just a 1 dimensional array, like [1,0]) the ARM devboard always outputs some weird value compared to the output of the python script. When not using the input tensor, everything works as expected.
Other infoBecause no wiki on uTensor exists yet, I've used a tutorial to learn about uTensor. The tutorial I've used can be found here: https://blog.hackster.io/simple-neural-network-on-mcus-a7cbd3dc108c The code I've written is based on the tutorial and does not include any cost/loss function and is not capable of 'learning' anything. The code is just for debugging.
The questionWhat is the reason an input tensor makes the application output unexpected values? How can I possibly fix this?
Code and outputPython script
...ANSWER
Answered 2019-Sep-24 at 07:24Changing the datatype in the C++ code to float did the trick! I'm still not quite sure how I did not think about this.
QUESTION
I'm new to the Julia programming language, and still learning it by writing code that I've already written in Python (or, at least, tried out in Python).
There is an article which explains how to make a very simple neural network: https://medium.com/technology-invention-and-more/how-to-build-a-simple-neural-network-in-9-lines-of-python-code-cc8f23647ca1.
I tried the code in this article out in Python, at it's working fine. However, I haven't used linear algebra things in Python before (like dot). Now I'm trying to translate this code to Julia, but there are some things I can't understand. Here is my Julia code:
...ANSWER
Answered 2019-Apr-13 at 18:30Here is the code adjusted to Julia:
QUESTION
Is that possible to export a neural network algorithm, like this one published by this guy to a CoreML model?
from numpy import exp, array, random, dot
...ANSWER
Answered 2019-Feb-05 at 16:55Yes, this is possible. You can use the NeuralNetworkBuilder
class from coremltools for this.
QUESTION
I was trying to create a Simple Neural Network through MATLAB (reference https://becominghuman.ai/making-a-simple-neural-network-2ea1de81ec20, although the author has coded in JavaScript, I wanted to do the same using MATLAB). I created my own MATLAB Live Script, but I am really confused as to my weights vector I created does not update. I am trying to add a learning rate of 0.20 to the weights(3) element, so as to make it reach 1 (I am trying 6 trials for training the network). I am new to using MATLAB and generally code in Python, so if I the mistake I am making/the thing I am missing is kindly explained or what line of code is wrong, I would be grateful. Thanks a lot!
Here is my piece of code:-
...ANSWER
Answered 2018-Sep-30 at 16:07Sounds like you missed a loop in the learn
function, double check with the original article.
QUESTION
I'm trying to understand how a simple forward neural network works... starting off with the example here I have simplified it to make a trainer that generally gives a 100% accurate "AND" neuron:
...ANSWER
Answered 2018-Jul-26 at 05:02The result you see in your print
statements are after the softmax
operation.
[1 1] . [-.70 .77; -.64 .81] + [1.9 -0.62] = [.53 .96]
Then
exp(.53) = 1.69, exp(.96) = 2.62
so result is
[1.69/(1.69+2.62) 2.62/(1.69+2.62)] = [.39 .61]
(obviously with rounding errors)
Also note that before taking the softmax technically you have a relu
activation, but since that is the identity for positive numbers, it doesn't have an effect for the [1 1]
example. It would make a difference for the [1 0]
example, as the second component of your Wx + b
is negative, which would then be zeroed out.
QUESTION
I am working on the following keras convolutional neural network tutorial https://gist.github.com/fchollet/0830affa1f7f19fd47b06d4cf89ed44d
After training the model I want to test the model on sample images, and also label the images. I realize that I have to use predict method that generates an array that shows which label gets what score for a particular image. But I am having trouble using this method. If the images are in the folder test_images and there are 20 of them, how do I test these images and get the prediction?
This is how I've gotten with one image (even though I want it for multiple images):
...ANSWER
Answered 2017-Oct-25 at 07:07model.predict
works by processing an array of samples, not just one image, so you are missing the batch/samples dimension, which in your case would only be just one image. You just have to reshape the array:
QUESTION
I got really interested in artificial neural networks (ANN) and red into it. But there is one thing i just can't seem to figure out.
When evaluating by how much a weight should be adjusted to reduce the error the ANN makes into account:
- the error (obviously),
*
- the input (self-explanatory to me as well)
*
- and the derivative of the sigmoid of the output (???).
But how does the last point even matter? I know it's supposed to represent how confident the ANN is with this particular weight, but isn't the error the key to how much the weight should be adjusted? Why would I care about how confident my ANN is with this weight if the output is just wrong?
I got my insights (and my confusion) from this post.
...ANSWER
Answered 2017-Feb-01 at 17:55Intuitions about how something works are in generally right, but in specifics they might not be right. This is the case for your intuitions of the error function, which are not right. Let's remember how the error is constructed, the output of a single neuron is:
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Install simple-neural-network
You can use simple-neural-network like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.
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