Why CLRS example on residual networks does not follows its formula?Why is the complexity of negative-cycle-cancelling $O(V^2AUW)$?CLRS - Maxflow Augmented Flow Lemma 26.1 - don't understand use of def. in proofFord-Fulkerson algorithm clarificationLinear programming formulation of cheapest k-edge path between two nodesWhy is it that the flow value can increased along an augmenting path $p$ in a residual network?Maximum flow with Edmonds–Karp algorithmHow would one construct conjunctively local predicate of order k for checking if a shape is Convex?Equivalence of minimum cost circulation problem and minimum cost max flow problemGiven max-flow determine if edge is in a min-cutWhat is the intuition behind the way of reading off a dual optimal solution from simplex primal tabular in CLRS?
Is there any sparring that doesn't involve punches to the head?
Motorized valve interfering with button?
How did the USSR manage to innovate in an environment characterized by government censorship and high bureaucracy?
Type 1 Error & Type 2 Error's pregnancy test analogy: is it legit?
Is the month field really deprecated?
Why did the Germans forbid the possession of pet pigeons in Rostov-on-Don in 1941?
Underlining section titles
Why are 150k or 200k jobs considered good when there are 300k+ births a month?
strToHex ( string to its hex representation as string)
declaring a variable twice in IIFE
Is the language <p,n> belongs to NP class?
Can an x86 CPU running in real mode be considered to be basically an 8086 CPU?
Shell script not opening as desktop application
Suffixes -unt and -ut-
How to make payment on the internet without leaving a money trail?
How can bays and straits be determined in a procedurally generated map?
Can I use wish to become the ruler of all dragons?
Why has Russell's definition of numbers using equivalence classes been finally abandoned? ( If it has actually been abandoned).
Methods for deciding between [odd number] players
Theorems that impeded progress
Draw simple lines in Inkscape
Japan - Plan around max visa duration
Why was the small council so happy for Tyrion to become the Master of Coin?
I probably found a bug with the sudo apt install function
Why CLRS example on residual networks does not follows its formula?
Why is the complexity of negative-cycle-cancelling $O(V^2AUW)$?CLRS - Maxflow Augmented Flow Lemma 26.1 - don't understand use of def. in proofFord-Fulkerson algorithm clarificationLinear programming formulation of cheapest k-edge path between two nodesWhy is it that the flow value can increased along an augmenting path $p$ in a residual network?Maximum flow with Edmonds–Karp algorithmHow would one construct conjunctively local predicate of order k for checking if a shape is Convex?Equivalence of minimum cost circulation problem and minimum cost max flow problemGiven max-flow determine if edge is in a min-cutWhat is the intuition behind the way of reading off a dual optimal solution from simplex primal tabular in CLRS?
$begingroup$
I am learning algorithms to solve Maximum Flow problem by reading the CRLS book and confused by the following figure:

That is:
A flow in a residual network provides a roadmap for adding flow to the
original flow network. If $f$ is a flow in $G$ and $f'$ is a flow in
the corresponding residual network $G_f$, we define $f uparrow f'$,
the augmentation of flow $f$ by $f'$, to be a function from $V times V$ to
$R$, defined by
$$(f uparrow f')(u, v) = begincases f(u,v) + f'(u, v) - f'(v, u) &
> textif (u,v) $in$ E \ 0 & textotherwise endcases$$
How the flow network in (c), for example $(s, v_2)$ got the flow 12 ?
If we follow the formula, it must have a flow 5:
$8 + 5 - 8 = 5$
algorithms network-flow
$endgroup$
add a comment |
$begingroup$
I am learning algorithms to solve Maximum Flow problem by reading the CRLS book and confused by the following figure:

That is:
A flow in a residual network provides a roadmap for adding flow to the
original flow network. If $f$ is a flow in $G$ and $f'$ is a flow in
the corresponding residual network $G_f$, we define $f uparrow f'$,
the augmentation of flow $f$ by $f'$, to be a function from $V times V$ to
$R$, defined by
$$(f uparrow f')(u, v) = begincases f(u,v) + f'(u, v) - f'(v, u) &
> textif (u,v) $in$ E \ 0 & textotherwise endcases$$
How the flow network in (c), for example $(s, v_2)$ got the flow 12 ?
If we follow the formula, it must have a flow 5:
$8 + 5 - 8 = 5$
algorithms network-flow
$endgroup$
add a comment |
$begingroup$
I am learning algorithms to solve Maximum Flow problem by reading the CRLS book and confused by the following figure:

That is:
A flow in a residual network provides a roadmap for adding flow to the
original flow network. If $f$ is a flow in $G$ and $f'$ is a flow in
the corresponding residual network $G_f$, we define $f uparrow f'$,
the augmentation of flow $f$ by $f'$, to be a function from $V times V$ to
$R$, defined by
$$(f uparrow f')(u, v) = begincases f(u,v) + f'(u, v) - f'(v, u) &
> textif (u,v) $in$ E \ 0 & textotherwise endcases$$
How the flow network in (c), for example $(s, v_2)$ got the flow 12 ?
If we follow the formula, it must have a flow 5:
$8 + 5 - 8 = 5$
algorithms network-flow
$endgroup$
I am learning algorithms to solve Maximum Flow problem by reading the CRLS book and confused by the following figure:

That is:
A flow in a residual network provides a roadmap for adding flow to the
original flow network. If $f$ is a flow in $G$ and $f'$ is a flow in
the corresponding residual network $G_f$, we define $f uparrow f'$,
the augmentation of flow $f$ by $f'$, to be a function from $V times V$ to
$R$, defined by
$$(f uparrow f')(u, v) = begincases f(u,v) + f'(u, v) - f'(v, u) &
> textif (u,v) $in$ E \ 0 & textotherwise endcases$$
How the flow network in (c), for example $(s, v_2)$ got the flow 12 ?
If we follow the formula, it must have a flow 5:
$8 + 5 - 8 = 5$
algorithms network-flow
algorithms network-flow
asked 4 hours ago
maksadbekmaksadbek
1164
1164
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
That's not what the formula gives you. As the caption says, the capacity of the augmenting path in the residual network in (b) is $4$. Therefore we send 4 units of flow along the augmenting path from $s$ to $t$, namely, the path $s to v_2 to v_3 to t$. In particular, $f(s,v_2)=8$, $f'(s,v_2)=4$, and $f'(v_2,s)=0$, so the updated flow is $8+4-0=12$.
$endgroup$
add a comment |
$begingroup$
It is explained in part (b) of the caption of Figure 26.4.
The residual network $G_f$ with augmenting path $p$ shaded; its residual capacity is $c_f(p)=c_f(v_2,v_3)=4$.
Since the capacity of path $p$ is 4 (not 5), we find a flow $f'$ in the residual network $G_f$ that is defined by $f'(s,v_2)=f'(v_2,v_3)=f'(v_3,t)=4$. So for the network flow $fuparrow f'$ in (c), we have
$$ (fuparrow f')(v_2, v_3)=f(v_2,v_3)+f'(v_2,v_3) = 8+4=12.$$
$endgroup$
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
add a comment |
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: "419"
;
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
);
);
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%2fcs.stackexchange.com%2fquestions%2f106608%2fwhy-clrs-example-on-residual-networks-does-not-follows-its-formula%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
That's not what the formula gives you. As the caption says, the capacity of the augmenting path in the residual network in (b) is $4$. Therefore we send 4 units of flow along the augmenting path from $s$ to $t$, namely, the path $s to v_2 to v_3 to t$. In particular, $f(s,v_2)=8$, $f'(s,v_2)=4$, and $f'(v_2,s)=0$, so the updated flow is $8+4-0=12$.
$endgroup$
add a comment |
$begingroup$
That's not what the formula gives you. As the caption says, the capacity of the augmenting path in the residual network in (b) is $4$. Therefore we send 4 units of flow along the augmenting path from $s$ to $t$, namely, the path $s to v_2 to v_3 to t$. In particular, $f(s,v_2)=8$, $f'(s,v_2)=4$, and $f'(v_2,s)=0$, so the updated flow is $8+4-0=12$.
$endgroup$
add a comment |
$begingroup$
That's not what the formula gives you. As the caption says, the capacity of the augmenting path in the residual network in (b) is $4$. Therefore we send 4 units of flow along the augmenting path from $s$ to $t$, namely, the path $s to v_2 to v_3 to t$. In particular, $f(s,v_2)=8$, $f'(s,v_2)=4$, and $f'(v_2,s)=0$, so the updated flow is $8+4-0=12$.
$endgroup$
That's not what the formula gives you. As the caption says, the capacity of the augmenting path in the residual network in (b) is $4$. Therefore we send 4 units of flow along the augmenting path from $s$ to $t$, namely, the path $s to v_2 to v_3 to t$. In particular, $f(s,v_2)=8$, $f'(s,v_2)=4$, and $f'(v_2,s)=0$, so the updated flow is $8+4-0=12$.
answered 2 hours ago
D.W.♦D.W.
103k12129294
103k12129294
add a comment |
add a comment |
$begingroup$
It is explained in part (b) of the caption of Figure 26.4.
The residual network $G_f$ with augmenting path $p$ shaded; its residual capacity is $c_f(p)=c_f(v_2,v_3)=4$.
Since the capacity of path $p$ is 4 (not 5), we find a flow $f'$ in the residual network $G_f$ that is defined by $f'(s,v_2)=f'(v_2,v_3)=f'(v_3,t)=4$. So for the network flow $fuparrow f'$ in (c), we have
$$ (fuparrow f')(v_2, v_3)=f(v_2,v_3)+f'(v_2,v_3) = 8+4=12.$$
$endgroup$
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
add a comment |
$begingroup$
It is explained in part (b) of the caption of Figure 26.4.
The residual network $G_f$ with augmenting path $p$ shaded; its residual capacity is $c_f(p)=c_f(v_2,v_3)=4$.
Since the capacity of path $p$ is 4 (not 5), we find a flow $f'$ in the residual network $G_f$ that is defined by $f'(s,v_2)=f'(v_2,v_3)=f'(v_3,t)=4$. So for the network flow $fuparrow f'$ in (c), we have
$$ (fuparrow f')(v_2, v_3)=f(v_2,v_3)+f'(v_2,v_3) = 8+4=12.$$
$endgroup$
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
add a comment |
$begingroup$
It is explained in part (b) of the caption of Figure 26.4.
The residual network $G_f$ with augmenting path $p$ shaded; its residual capacity is $c_f(p)=c_f(v_2,v_3)=4$.
Since the capacity of path $p$ is 4 (not 5), we find a flow $f'$ in the residual network $G_f$ that is defined by $f'(s,v_2)=f'(v_2,v_3)=f'(v_3,t)=4$. So for the network flow $fuparrow f'$ in (c), we have
$$ (fuparrow f')(v_2, v_3)=f(v_2,v_3)+f'(v_2,v_3) = 8+4=12.$$
$endgroup$
It is explained in part (b) of the caption of Figure 26.4.
The residual network $G_f$ with augmenting path $p$ shaded; its residual capacity is $c_f(p)=c_f(v_2,v_3)=4$.
Since the capacity of path $p$ is 4 (not 5), we find a flow $f'$ in the residual network $G_f$ that is defined by $f'(s,v_2)=f'(v_2,v_3)=f'(v_3,t)=4$. So for the network flow $fuparrow f'$ in (c), we have
$$ (fuparrow f')(v_2, v_3)=f(v_2,v_3)+f'(v_2,v_3) = 8+4=12.$$
edited 2 hours ago
answered 2 hours ago
Apass.JackApass.Jack
14k1940
14k1940
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
add a comment |
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
1
1
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
$begingroup$
I think you mean $=12$ not $=8$.
$endgroup$
– D.W.♦
2 hours ago
add a comment |
Thanks for contributing an answer to Computer 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%2fcs.stackexchange.com%2fquestions%2f106608%2fwhy-clrs-example-on-residual-networks-does-not-follows-its-formula%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