Calculation of matrix according to Schubert's method











up vote
0
down vote

favorite












Schubert's method is the improvement of Broyden's method for the calculation of the quasi-newton update of a jacobian matrix, when the matrix itself is sparse. According to his paper, the update algorithm is
$$B_{n+1}=B_n - sum_{i=1}^mu_iu_i^T(B_np-y/t)frac{p_i^T}{p_i^Tp_i}$$
with $B$ a (sparse) matrix, $p$ and $y$ vectors, and $t$ a scalar. $p_i$ is defined as $p$ with the values corresponding to zero-entries in column $i$ in matrix $B$ set to zero. $u_i$ is the $i$-th column of the unit matrix of order $m$.

Based on my understanding that gives me
$$B_{n+1}=B_n - sum_{i=1}^munderbrace{underbrace{u_iu_i^T}_{=1}underbrace{(B_np-y/t)}_{text{column vector}}underbrace{frac{p_i^T}{p_i^Tp_i}}_{text{row vector}}}_{text{scalar}}$$
a scalar value, which then is added to the original matrix. That can not be correct. Thus, where did I make my mistake here?










share|cite|improve this question






















  • $u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
    – greg
    Dec 4 at 20:47

















up vote
0
down vote

favorite












Schubert's method is the improvement of Broyden's method for the calculation of the quasi-newton update of a jacobian matrix, when the matrix itself is sparse. According to his paper, the update algorithm is
$$B_{n+1}=B_n - sum_{i=1}^mu_iu_i^T(B_np-y/t)frac{p_i^T}{p_i^Tp_i}$$
with $B$ a (sparse) matrix, $p$ and $y$ vectors, and $t$ a scalar. $p_i$ is defined as $p$ with the values corresponding to zero-entries in column $i$ in matrix $B$ set to zero. $u_i$ is the $i$-th column of the unit matrix of order $m$.

Based on my understanding that gives me
$$B_{n+1}=B_n - sum_{i=1}^munderbrace{underbrace{u_iu_i^T}_{=1}underbrace{(B_np-y/t)}_{text{column vector}}underbrace{frac{p_i^T}{p_i^Tp_i}}_{text{row vector}}}_{text{scalar}}$$
a scalar value, which then is added to the original matrix. That can not be correct. Thus, where did I make my mistake here?










share|cite|improve this question






















  • $u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
    – greg
    Dec 4 at 20:47















up vote
0
down vote

favorite









up vote
0
down vote

favorite











Schubert's method is the improvement of Broyden's method for the calculation of the quasi-newton update of a jacobian matrix, when the matrix itself is sparse. According to his paper, the update algorithm is
$$B_{n+1}=B_n - sum_{i=1}^mu_iu_i^T(B_np-y/t)frac{p_i^T}{p_i^Tp_i}$$
with $B$ a (sparse) matrix, $p$ and $y$ vectors, and $t$ a scalar. $p_i$ is defined as $p$ with the values corresponding to zero-entries in column $i$ in matrix $B$ set to zero. $u_i$ is the $i$-th column of the unit matrix of order $m$.

Based on my understanding that gives me
$$B_{n+1}=B_n - sum_{i=1}^munderbrace{underbrace{u_iu_i^T}_{=1}underbrace{(B_np-y/t)}_{text{column vector}}underbrace{frac{p_i^T}{p_i^Tp_i}}_{text{row vector}}}_{text{scalar}}$$
a scalar value, which then is added to the original matrix. That can not be correct. Thus, where did I make my mistake here?










share|cite|improve this question













Schubert's method is the improvement of Broyden's method for the calculation of the quasi-newton update of a jacobian matrix, when the matrix itself is sparse. According to his paper, the update algorithm is
$$B_{n+1}=B_n - sum_{i=1}^mu_iu_i^T(B_np-y/t)frac{p_i^T}{p_i^Tp_i}$$
with $B$ a (sparse) matrix, $p$ and $y$ vectors, and $t$ a scalar. $p_i$ is defined as $p$ with the values corresponding to zero-entries in column $i$ in matrix $B$ set to zero. $u_i$ is the $i$-th column of the unit matrix of order $m$.

Based on my understanding that gives me
$$B_{n+1}=B_n - sum_{i=1}^munderbrace{underbrace{u_iu_i^T}_{=1}underbrace{(B_np-y/t)}_{text{column vector}}underbrace{frac{p_i^T}{p_i^Tp_i}}_{text{row vector}}}_{text{scalar}}$$
a scalar value, which then is added to the original matrix. That can not be correct. Thus, where did I make my mistake here?







matrices newton-raphson






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 4 at 10:50









arc_lupus

232218




232218












  • $u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
    – greg
    Dec 4 at 20:47




















  • $u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
    – greg
    Dec 4 at 20:47


















$u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
– greg
Dec 4 at 20:47






$u_i$ is a column vector, therefore $(u_iu_i^T)$ is a matrix; definitely not equal to the scalar value $1$.
– greg
Dec 4 at 20:47

















active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
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',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
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
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3025420%2fcalculation-of-matrix-according-to-schuberts-method%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics 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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3025420%2fcalculation-of-matrix-according-to-schuberts-method%23new-answer', 'question_page');
}
);

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







Popular posts from this blog

Bressuire

Cabo Verde

Gyllenstierna