Convolutions of two functionsDefine uniform B-spline basis functions via continuous convolutionHow Heaviside...

How does the math work for Perception checks?

Why does the Sun have different day lengths, but not the gas giants?

Can a Canadian Travel to the USA twice, less than 180 days each time?

Extract more than nine arguments that occur periodically in a sentence to use in macros in order to typset

A social experiment. What is the worst that can happen?

Can the US President recognize Israel’s sovereignty over the Golan Heights for the USA or does that need an act of Congress?

Can disgust be a key component of horror?

Store Credit Card Information in Password Manager?

Keeping a ball lost forever

What should you do when eye contact makes your subordinate uncomfortable?

How do you respond to a colleague from another team when they're wrongly expecting that you'll help them?

Does Doodling or Improvising on the Piano Have Any Benefits?

How do you make your own symbol when Detexify fails?

Can I still be respawned if I die by falling off the map?

The IT department bottlenecks progress. How should I handle this?

Hero deduces identity of a killer

Redundant comparison & "if" before assignment

Does IPv6 have similar concept of network mask?

Why is it that I can sometimes guess the next note?

Temporarily disable WLAN internet access for children, but allow it for adults

Are Captain Marvel's powers affected by Thanos' actions in Infinity War

How much character growth crosses the line into breaking the character

Is there a RAID 0 Equivalent for RAM?

Is this toilet slogan correct usage of the English language?



Convolutions of two functions


Define uniform B-spline basis functions via continuous convolutionHow Heaviside step function changes limits of integrationHow to obtain the convolution directly (not graphical) of the two functions $e^{-t}u(t)$ and $e^{-2t}u(t)$?Convolution of Two Shifted FunctionsConvolution integral involving two Heaviside functionsConvolution Integral - Shift propertyQuestion on the uniqueness of the densitiesprobability of two numbers picked from two distributions giving a fixed number multiplicationDifficult convolutions in probability problemsExample of non-zero functions with identically zero convolution













0












$begingroup$


I am having trouble understanding how you take the convolution of two functions.



For example, if $f_1(x) = x$, with x ranging from [0,X] how do I solve for $f_2(x)$ when
$$f_2(x) = int_{0}^{infty} f_1(x')f_1(x-x') dx'.$$
Do I need to use an indicator function?



Thanks










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    This integral does not converge for your choice of $f_1$.
    $endgroup$
    – Mars Plastic
    Mar 13 at 16:22










  • $begingroup$
    Also: I suppose $*$ denotes multiplication and not convolution?
    $endgroup$
    – Mars Plastic
    Mar 13 at 17:01










  • $begingroup$
    yes you are correct
    $endgroup$
    – Calvin Xu
    Mar 14 at 17:03
















0












$begingroup$


I am having trouble understanding how you take the convolution of two functions.



For example, if $f_1(x) = x$, with x ranging from [0,X] how do I solve for $f_2(x)$ when
$$f_2(x) = int_{0}^{infty} f_1(x')f_1(x-x') dx'.$$
Do I need to use an indicator function?



Thanks










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    This integral does not converge for your choice of $f_1$.
    $endgroup$
    – Mars Plastic
    Mar 13 at 16:22










  • $begingroup$
    Also: I suppose $*$ denotes multiplication and not convolution?
    $endgroup$
    – Mars Plastic
    Mar 13 at 17:01










  • $begingroup$
    yes you are correct
    $endgroup$
    – Calvin Xu
    Mar 14 at 17:03














0












0








0





$begingroup$


I am having trouble understanding how you take the convolution of two functions.



For example, if $f_1(x) = x$, with x ranging from [0,X] how do I solve for $f_2(x)$ when
$$f_2(x) = int_{0}^{infty} f_1(x')f_1(x-x') dx'.$$
Do I need to use an indicator function?



Thanks










share|cite|improve this question











$endgroup$




I am having trouble understanding how you take the convolution of two functions.



For example, if $f_1(x) = x$, with x ranging from [0,X] how do I solve for $f_2(x)$ when
$$f_2(x) = int_{0}^{infty} f_1(x')f_1(x-x') dx'.$$
Do I need to use an indicator function?



Thanks







integration probability-distributions convolution






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Mar 14 at 17:02







Calvin Xu

















asked Mar 13 at 16:15









Calvin XuCalvin Xu

11




11








  • 1




    $begingroup$
    This integral does not converge for your choice of $f_1$.
    $endgroup$
    – Mars Plastic
    Mar 13 at 16:22










  • $begingroup$
    Also: I suppose $*$ denotes multiplication and not convolution?
    $endgroup$
    – Mars Plastic
    Mar 13 at 17:01










  • $begingroup$
    yes you are correct
    $endgroup$
    – Calvin Xu
    Mar 14 at 17:03














  • 1




    $begingroup$
    This integral does not converge for your choice of $f_1$.
    $endgroup$
    – Mars Plastic
    Mar 13 at 16:22










  • $begingroup$
    Also: I suppose $*$ denotes multiplication and not convolution?
    $endgroup$
    – Mars Plastic
    Mar 13 at 17:01










  • $begingroup$
    yes you are correct
    $endgroup$
    – Calvin Xu
    Mar 14 at 17:03








1




1




$begingroup$
This integral does not converge for your choice of $f_1$.
$endgroup$
– Mars Plastic
Mar 13 at 16:22




$begingroup$
This integral does not converge for your choice of $f_1$.
$endgroup$
– Mars Plastic
Mar 13 at 16:22












$begingroup$
Also: I suppose $*$ denotes multiplication and not convolution?
$endgroup$
– Mars Plastic
Mar 13 at 17:01




$begingroup$
Also: I suppose $*$ denotes multiplication and not convolution?
$endgroup$
– Mars Plastic
Mar 13 at 17:01












$begingroup$
yes you are correct
$endgroup$
– Calvin Xu
Mar 14 at 17:03




$begingroup$
yes you are correct
$endgroup$
– Calvin Xu
Mar 14 at 17:03










1 Answer
1






active

oldest

votes


















1












$begingroup$

in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.



If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.






share|cite|improve this answer









$endgroup$













    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',
    autoActivateHeartbeat: false,
    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%2f3146799%2fconvolutions-of-two-functions%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1












    $begingroup$

    in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.



    If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.



      If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.



        If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.






        share|cite|improve this answer









        $endgroup$



        in your example you sustitute $f_1(x')=x'$ and $f_1(x-x')=x-x'$ in an analagous way and solve the integral having the $x'$ as your integral's variable.



        If the integral converges, you will get a result in terms of x and it will be the convolution of $f_1$ with itself. if the integral dows not converge, you can't make the convolution.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Mar 13 at 17:07









        Carlos Adrian Perez EstradaCarlos Adrian Perez Estrada

        414




        414






























            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.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3146799%2fconvolutions-of-two-functions%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

            Nidaros erkebispedøme

            Birsay

            Where did Arya get these scars? Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar Manara Favourite questions and answers from the 1st quarter of 2019Why did Arya refuse to end it?Has the pronunciation of Arya Stark's name changed?Has Arya forgiven people?Why did Arya Stark lose her vision?Why can Arya still use the faces?Has the Narrow Sea become narrower?Does Arya Stark know how to make poisons outside of the House of Black and White?Why did Nymeria leave Arya?Why did Arya not kill the Lannister soldiers she encountered in the Riverlands?What is the current canonical age of Sansa, Bran and Arya Stark?