Gradient Descent in ReLU Neural Network
$begingroup$
I’m new to machine learning and recently facing a problem on back propagation of training a neural network using ReLU activation function shown in the figure. My problem is to update the weights matrices in the hidden and output layers.
The cost function is given as:
$J(Theta) = sumlimits_{i=1}^2 frac{1}{2} left(a_i^{(3)} - y_iright)^2$
where $y_i$ is the $i$-th output from output layer.
Using the gradient descent algorithm, the weights matrices can be updated by:
$Theta_{jk}^{(2)} := Theta_{jk}^{(2)} - alphafrac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$
$Theta_{ij}^{(3)} := Theta_{ij}^{(3)} - alphafrac{partial J(Theta)}{partial Theta_{ij}^{(3)}}$
I understand how to update the weight matrix at output layer $Theta_{ij}^{(3)}$, however I don’t know how to update that from the input layer to hidden layer $Theta_{jk}^{(2)}$ involving the ReLU activation units, i.e. not understanding how to get $frac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$.
Can anyone help me understand how to derive the gradient on the cost function...?
neural-network gradient-descent activation-function
New contributor
$endgroup$
add a comment |
$begingroup$
I’m new to machine learning and recently facing a problem on back propagation of training a neural network using ReLU activation function shown in the figure. My problem is to update the weights matrices in the hidden and output layers.
The cost function is given as:
$J(Theta) = sumlimits_{i=1}^2 frac{1}{2} left(a_i^{(3)} - y_iright)^2$
where $y_i$ is the $i$-th output from output layer.
Using the gradient descent algorithm, the weights matrices can be updated by:
$Theta_{jk}^{(2)} := Theta_{jk}^{(2)} - alphafrac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$
$Theta_{ij}^{(3)} := Theta_{ij}^{(3)} - alphafrac{partial J(Theta)}{partial Theta_{ij}^{(3)}}$
I understand how to update the weight matrix at output layer $Theta_{ij}^{(3)}$, however I don’t know how to update that from the input layer to hidden layer $Theta_{jk}^{(2)}$ involving the ReLU activation units, i.e. not understanding how to get $frac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$.
Can anyone help me understand how to derive the gradient on the cost function...?
neural-network gradient-descent activation-function
New contributor
$endgroup$
add a comment |
$begingroup$
I’m new to machine learning and recently facing a problem on back propagation of training a neural network using ReLU activation function shown in the figure. My problem is to update the weights matrices in the hidden and output layers.
The cost function is given as:
$J(Theta) = sumlimits_{i=1}^2 frac{1}{2} left(a_i^{(3)} - y_iright)^2$
where $y_i$ is the $i$-th output from output layer.
Using the gradient descent algorithm, the weights matrices can be updated by:
$Theta_{jk}^{(2)} := Theta_{jk}^{(2)} - alphafrac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$
$Theta_{ij}^{(3)} := Theta_{ij}^{(3)} - alphafrac{partial J(Theta)}{partial Theta_{ij}^{(3)}}$
I understand how to update the weight matrix at output layer $Theta_{ij}^{(3)}$, however I don’t know how to update that from the input layer to hidden layer $Theta_{jk}^{(2)}$ involving the ReLU activation units, i.e. not understanding how to get $frac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$.
Can anyone help me understand how to derive the gradient on the cost function...?
neural-network gradient-descent activation-function
New contributor
$endgroup$
I’m new to machine learning and recently facing a problem on back propagation of training a neural network using ReLU activation function shown in the figure. My problem is to update the weights matrices in the hidden and output layers.
The cost function is given as:
$J(Theta) = sumlimits_{i=1}^2 frac{1}{2} left(a_i^{(3)} - y_iright)^2$
where $y_i$ is the $i$-th output from output layer.
Using the gradient descent algorithm, the weights matrices can be updated by:
$Theta_{jk}^{(2)} := Theta_{jk}^{(2)} - alphafrac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$
$Theta_{ij}^{(3)} := Theta_{ij}^{(3)} - alphafrac{partial J(Theta)}{partial Theta_{ij}^{(3)}}$
I understand how to update the weight matrix at output layer $Theta_{ij}^{(3)}$, however I don’t know how to update that from the input layer to hidden layer $Theta_{jk}^{(2)}$ involving the ReLU activation units, i.e. not understanding how to get $frac{partial J(Theta)}{partial Theta_{jk}^{(2)}}$.
Can anyone help me understand how to derive the gradient on the cost function...?
neural-network gradient-descent activation-function
neural-network gradient-descent activation-function
New contributor
New contributor
New contributor
asked 4 mins ago
nullnull
1
1
New contributor
New contributor
add a comment |
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "557"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
null is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f49666%2fgradient-descent-in-relu-neural-network%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
null is a new contributor. Be nice, and check out our Code of Conduct.
null is a new contributor. Be nice, and check out our Code of Conduct.
null is a new contributor. Be nice, and check out our Code of Conduct.
null is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Data Science Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f49666%2fgradient-descent-in-relu-neural-network%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown