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

What connection does MS Office have to Netscape Navigator?

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

How to Reset Passwords on Multiple Websites Easily?

How does the mv command work with external drives?

In excess I'm lethal

Why is the US ranked as #45 in Press Freedom ratings, despite its extremely permissive free speech laws?

How to count occurrences of text in a file?

Why do airplanes bank sharply to the right after air-to-air refueling?

How do I avoid eval and parse?

Non-deterministic sum of floats

Return the Closest Prime Number

How to solve a differential equation with a term to a power?

Preparing Indesign booklet with .psd graphics for print

Is it ever safe to open a suspicious html file (e.g. email attachment)?

Is there an analogue of projective spaces for proper schemes?

What flight has the highest ratio of time difference to flight time?

Why has the US not been more assertive in confronting Russia in recent years?

What does convergence in distribution "in the Gromov–Hausdorff" sense mean?

What exact does MIB represent in SNMP? How is it different from OID?

What can we do to stop prior company from asking us questions?

Complex fractions

Should I tutor a student who I know has cheated on their homework?

What is the result of assigning to std::vector<T>::begin()?

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



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
    4 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
    4 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 4 hours ago









NioushaNiousha

1596




1596











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

















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
















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





$begingroup$
do you know about phase unwrapping?
$endgroup$
– robert bristow-johnson
4 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 4 hours ago









        MBaz

        9,01041733




        9,01041733










        answered 4 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

            Invision Community Contents History See also References External links Navigation menuProprietaryinvisioncommunity.comIPS Community ForumsIPS Community Forumsthis blog entry"License Changes, IP.Board 3.4, and the Future""Interview -- Matt Mecham of Ibforums""CEO Invision Power Board, Matt Mecham Is a Liar, Thief!"IPB License Explanation 1.3, 1.3.1, 2.0, and 2.1ArchivedSecurity Fixes, Updates And Enhancements For IPB 1.3.1Archived"New Demo Accounts - Invision Power Services"the original"New Default Skin"the original"Invision Power Board 3.0.0 and Applications Released"the original"Archived copy"the original"Perpetual licenses being done away with""Release Notes - Invision Power Services""Introducing: IPS Community Suite 4!"Invision Community Release Notes

            Canceling a color specificationRandomly assigning color to Graphics3D objects?Default color for Filling in Mathematica 9Coloring specific elements of sets with a prime modified order in an array plotHow to pick a color differing significantly from the colors already in a given color list?Detection of the text colorColor numbers based on their valueCan color schemes for use with ColorData include opacity specification?My dynamic color schemes

            Ласкавець круглолистий Зміст Опис | Поширення | Галерея | Примітки | Посилання | Навігаційне меню58171138361-22960890446Bupleurum rotundifoliumEuro+Med PlantbasePlants of the World Online — Kew ScienceGermplasm Resources Information Network (GRIN)Ласкавецькн. VI : Літери Ком — Левиправивши або дописавши її