Phase of a real number The Next CEO of Stack OverflowWhat is the difference between phase...

Would a completely good Muggle be able to use a wand?

Contours of a clandestine nature

How did people program for Consoles with multiple CPUs?

Rotate a column

Does it take more energy to get to Venus or to Mars?

How to start emacs in "nothing" mode (`fundamental-mode`)

How to invert MapIndexed on a ragged structure? How to construct a tree from rules?

What benefits would be gained by using human laborers instead of drones in deep sea mining?

How does the mv command work with external drives?

Is it possible to search for a directory/file combination?

What's the best way to handle refactoring a big file?

What happened in Rome, when the western empire "fell"?

Why do professional authors make "consistency" mistakes? And how to avoid them?

What happens if you roll doubles 3 times then land on "Go to jail?"

Preparing Indesign booklet with .psd graphics for print

In excess I'm lethal

Has this building technique been used in an official set?

Is micro rebar a better way to reinforce concrete than rebar?

Which tube will fit a -(700 x 25c) wheel?

Why do we use the plural of movies in this phrase "We went to the movies last night."?

Bold, vivid family

How do I make a variable always equal to the result of some calculations?

Indicator light circuit

How do I transpose the 1st and -1th levels of an arbitrarily nested array?



Phase of a real number



The Next CEO of Stack OverflowWhat is the difference between phase delay and group delay?How do you relate imaginary numbers with phase shift? How to imagine this?Phase factors for an 32 point fftbaffled by fft phase spectrum!How are phase values able to capture motion from video?In filter design, why isn't it possible to have a frequency response with phase 0?Extracting accurate phase and amplitude information from FFT with an arbitrary number of samplesContinuous phase for phase delay calculus in FIR filtersPhase spectrum of 2D real functionPlotting the Phase Response












1












$begingroup$


Could someone please explain in what case the phase of a real number is equal to -pi (and not pi)?



I know that for positive numbers, the phase is zero. For zero, we define the phase as zero as well. And for negative numbers, the phase would be pi. But I was reading some script and there it says the phase of a real number is either 0, pi, or -pi.










share|improve this question









$endgroup$












  • $begingroup$
    do you know about phase unwrapping?
    $endgroup$
    – robert bristow-johnson
    5 hours ago


















1












$begingroup$


Could someone please explain in what case the phase of a real number is equal to -pi (and not pi)?



I know that for positive numbers, the phase is zero. For zero, we define the phase as zero as well. And for negative numbers, the phase would be pi. But I was reading some script and there it says the phase of a real number is either 0, pi, or -pi.










share|improve this question









$endgroup$












  • $begingroup$
    do you know about phase unwrapping?
    $endgroup$
    – robert bristow-johnson
    5 hours ago
















1












1








1





$begingroup$


Could someone please explain in what case the phase of a real number is equal to -pi (and not pi)?



I know that for positive numbers, the phase is zero. For zero, we define the phase as zero as well. And for negative numbers, the phase would be pi. But I was reading some script and there it says the phase of a real number is either 0, pi, or -pi.










share|improve this question









$endgroup$




Could someone please explain in what case the phase of a real number is equal to -pi (and not pi)?



I know that for positive numbers, the phase is zero. For zero, we define the phase as zero as well. And for negative numbers, the phase would be pi. But I was reading some script and there it says the phase of a real number is either 0, pi, or -pi.







phase






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 5 hours ago









NioushaNiousha

1596




1596












  • $begingroup$
    do you know about phase unwrapping?
    $endgroup$
    – robert bristow-johnson
    5 hours ago




















  • $begingroup$
    do you know about phase unwrapping?
    $endgroup$
    – robert bristow-johnson
    5 hours ago


















$begingroup$
do you know about phase unwrapping?
$endgroup$
– robert bristow-johnson
5 hours ago






$begingroup$
do you know about phase unwrapping?
$endgroup$
– robert bristow-johnson
5 hours ago












1 Answer
1






active

oldest

votes


















2












$begingroup$

Or $2pi$, or $3pi$, or any integer multiple of $pi$. Any odd multiple corresponds to -1 + 0i and any even multiple corresponds to 1 + 0i, aka -1 and 1.



"Phase of a real number" is a little bit of a misleading label. What is required here is an understanding of the complex plane and what "phase" means in terms of a DFT bin value.



Your question is equivalent to "For what values of arg(z) is z a real number?"



If that is meaningless to you, I suggest you start by reading two blog articles of mine:



The Exponential Nature of the Complex Unit Circle



And the newest:



Angle Addition Formulas from Euler's Formula



There are of course many other searches. Your terms should be "complex plane real values" for a start.



This is essential foundation material for a lot of DSP concepts.






share|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: "295"
    };
    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
    },
    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%2fdsp.stackexchange.com%2fquestions%2f56336%2fphase-of-a-real-number%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









    2












    $begingroup$

    Or $2pi$, or $3pi$, or any integer multiple of $pi$. Any odd multiple corresponds to -1 + 0i and any even multiple corresponds to 1 + 0i, aka -1 and 1.



    "Phase of a real number" is a little bit of a misleading label. What is required here is an understanding of the complex plane and what "phase" means in terms of a DFT bin value.



    Your question is equivalent to "For what values of arg(z) is z a real number?"



    If that is meaningless to you, I suggest you start by reading two blog articles of mine:



    The Exponential Nature of the Complex Unit Circle



    And the newest:



    Angle Addition Formulas from Euler's Formula



    There are of course many other searches. Your terms should be "complex plane real values" for a start.



    This is essential foundation material for a lot of DSP concepts.






    share|improve this answer











    $endgroup$


















      2












      $begingroup$

      Or $2pi$, or $3pi$, or any integer multiple of $pi$. Any odd multiple corresponds to -1 + 0i and any even multiple corresponds to 1 + 0i, aka -1 and 1.



      "Phase of a real number" is a little bit of a misleading label. What is required here is an understanding of the complex plane and what "phase" means in terms of a DFT bin value.



      Your question is equivalent to "For what values of arg(z) is z a real number?"



      If that is meaningless to you, I suggest you start by reading two blog articles of mine:



      The Exponential Nature of the Complex Unit Circle



      And the newest:



      Angle Addition Formulas from Euler's Formula



      There are of course many other searches. Your terms should be "complex plane real values" for a start.



      This is essential foundation material for a lot of DSP concepts.






      share|improve this answer











      $endgroup$
















        2












        2








        2





        $begingroup$

        Or $2pi$, or $3pi$, or any integer multiple of $pi$. Any odd multiple corresponds to -1 + 0i and any even multiple corresponds to 1 + 0i, aka -1 and 1.



        "Phase of a real number" is a little bit of a misleading label. What is required here is an understanding of the complex plane and what "phase" means in terms of a DFT bin value.



        Your question is equivalent to "For what values of arg(z) is z a real number?"



        If that is meaningless to you, I suggest you start by reading two blog articles of mine:



        The Exponential Nature of the Complex Unit Circle



        And the newest:



        Angle Addition Formulas from Euler's Formula



        There are of course many other searches. Your terms should be "complex plane real values" for a start.



        This is essential foundation material for a lot of DSP concepts.






        share|improve this answer











        $endgroup$



        Or $2pi$, or $3pi$, or any integer multiple of $pi$. Any odd multiple corresponds to -1 + 0i and any even multiple corresponds to 1 + 0i, aka -1 and 1.



        "Phase of a real number" is a little bit of a misleading label. What is required here is an understanding of the complex plane and what "phase" means in terms of a DFT bin value.



        Your question is equivalent to "For what values of arg(z) is z a real number?"



        If that is meaningless to you, I suggest you start by reading two blog articles of mine:



        The Exponential Nature of the Complex Unit Circle



        And the newest:



        Angle Addition Formulas from Euler's Formula



        There are of course many other searches. Your terms should be "complex plane real values" for a start.



        This is essential foundation material for a lot of DSP concepts.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 5 hours ago









        MBaz

        9,01041733




        9,01041733










        answered 5 hours ago









        Cedron DawgCedron Dawg

        3,0632312




        3,0632312






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Signal Processing 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%2fdsp.stackexchange.com%2fquestions%2f56336%2fphase-of-a-real-number%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

            VNC viewer RFB protocol error: bad desktop size 0x0I Cannot Type the Key 'd' (lowercase) in VNC Viewer...

            Couldn't open a raw socket. Error: Permission denied (13) (nmap)Is it possible to run networking commands...

            Why not use the yoke to control yaw, as well as pitch and roll? Announcing the arrival of...