Octave Definition and 40 Threads

In music, an octave (Latin: octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems". The interval between the first and second harmonics of the harmonic series is an octave.
In Western music notation, notes separated by an octave (or multiple octaves) have the same letter name and are of the same pitch class.
To emphasize that it is one of the perfect intervals (including unison, perfect fourth, and perfect fifth), the octave is designated P8. Other interval qualities are also possible, though rare. The octave above or below an indicated note is sometimes abbreviated 8a or 8va (Italian: all'ottava), 8va bassa (Italian: all'ottava bassa, sometimes also 8vb), or simply 8 for the octave in the direction indicated by placing this mark above or below the staff.

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  1. WMDhamnekar

    MHB When to use equivalence relations? How to write it in octave?

    Sometimes to help describe one expression, another expression is shown that produces identical results. The exact equivalence of expressions is indicated with ‘ ≡’. For example: rot90 ([1, 2; 3, 4], -1) ≡ rot90 ([1, 2; 3, 4], 3) ≡ rot90 ([1, 2; 3, 4], 7) What is the meaning of 'rot90;? What...
  2. Abhisheko07

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  3. Ugnius

    Comp Sci Octave coding -- solving a quadratic equation and then using the roots

    Hi , I had to solve a quadratic equation , i got two roots as an answer ( ans= x1 / x2) , and now i need to use one of those answers to complete further tasks like finding y from x+y=c so i need to use x1 and x2 from roots , i was wondering if that's possible and how
  4. dRic2

    How Do You Correctly Parse and Convert Strings to Numbers in Octave?

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  5. D

    Structuring Code for Global Parameters in Octave

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  6. D

    Structure of code for ODE solution in Octave

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  7. D

    Difficulties solving ODE in Octave

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  8. Wrichik Basu

    MATLAB Forcing the best fit line to pass through a certain point (Octave)

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  9. D

    Need to change display colors in Octave 5.1

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  10. T

    A How to find the Jordan Canonical Form of a 5x5 matrix and its steps?

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  11. DaveC426913

    Music Understanding Music's Irregular Octave Divisions

    One octave is a doubling of frequency, say, 440Hz to 880Hz for A. If I understand correctly, that is divided into 12 equal divisions, denoted by all 12 naturals and sharps/flats. Of those 12, any given key tends to use only 8. Why do these 8, which are not evenly distributed throughout the...
  12. J

    A Calculate Third Octave Band Response from Narrowband Data

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  13. J

    MATLAB Octave integral computation help

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  14. P

    Calculating Heat Loss in Long Pipe Transfer with Octave

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  15. Remixex

    Am i being taught programming right?

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  16. M

    Magnetic field representation in Octave

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  17. jlefevre76

    Octave debug info randomly displayed

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  18. Jawz

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  19. R

    I plotting some data using octave

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  20. M

    Help with Octave for system of ODEs

    Hi, I am having a lot of trouble with Octave as I try to solve a system of ODEs. Any help is appreciated, I am a complete newbie with Octave and numerical solving. Let's try a very simple one. Suppose I had a pair of ODEs with a and b being functions of time \frac{da}{dt}=2ba...
  21. O

    Octave partial fraction decomposition help

    So I'm trying to figure out how to decompose the following using octave: 85000/[(s^2+250^2)(0.2s^2+40s+10000)] I tried using the residue command but I think that only works if the polynomials have real roots, which these don't. When I do use residue I get the following: b =...
  22. V

    Searching for Octave Bugs - Need Help?

    Hello guys, I am familiar with Matlab. And i know Octave is similar to Matlab. I am planning to fix a bug in Octave. Therefore, i would like to ask if anyone know about any bug in Octave (there must be many) or where can i find more information about the same? Thanks!
  23. D

    Octave with C++ on Fedora 16 | Finding oct.h

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  24. P

    Third octave filter and voltage obtained

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  25. M

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  26. A

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  27. E

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  28. silvermane

    Verifying the Interval of a Fifth vs an Octave in Early Greek Music

    Problem (in my words): So, in music, the interval of an octave between two tones corresponds to doubling the frequency of the oscillation. In early Greek music, the interval of a fifth corresponded to multiplying the frequency by 3/2. With this definition of a fifth, prove that non of the...
  29. R

    MATLAB Running MATLAB Programs in Octave

    Hello to all I downloaded Octave. I read that it will run MATLAB programs, but how do you do that? Thanks
  30. L

    What initial conditions should I use for my system of differential equations?

    Hi, I've just started using Octave and I'd like to use it to solve and plot a system of differential equations, but I keep getting the same error which I don't understand. What have I done wrong in my code? Outline: Initial conditions x1 = 1 x2 = 1.27 x 10^-6 x3 = 0 t = 0 - 140 days...
  31. M

    Octave: Help with implementing midpoint rule

    I got the code from my textbook and it is supposed to work in matlab function r = midpoint(a,b,f,n) f = fcnchk(f); h = (b-a)/n; x = (a+h*0.5):h:(b-h*0.5); y = feval(f,x); r = h*sum(y(1:n)); The code fails on feval I go tcnchk from wikipedia function f=fcnchk(x, n) f = x; end...
  32. Angelos K

    How can I display Greek letters in legends using Octave plot?

    Homework Statement Hi! I'm sorry if this is misplaced, but I didn't know where else to post it. In my thesis I need greek letters to appear in a legend for a figure generated with octave. Now I normally know how to do that. F.e. if I say: legend('\alpha','\kappa') everythging works...
  33. M

    MATLAB Octave vs Matlab: Will I Run Into Trouble?

    Has anyone here used the open source Octave as opposed to Matlab? I don't have access to Matlab right now and Octave claims to be compatible to a high extent. Will I run into trouble if I learn Octave thoroughly then have to switch to Matlab for collaborative reasons?
  34. P

    Finding a Cannon Problem to Solve with GNU Octave

    Hi to all! My teacher told me to find a problem from the internet based on Cannon throwing a ball, and then to try to solve it using gnu octave. My problem is that I didnt find any problem with cannon. Can you please tell me where to find? Best Regards
  35. M

    Help with Octave, installing package

    Hey, I need some help with installing a package in Octave. I have never done this before so I'm not sure what I am doing wronge. I have downloaded econometrics, changed directory and typed: "pkg install econometrics-1.0.7.tar.gz" and I get """warning: implicit conversion from matrix to string...
  36. I

    Solid State Physics - Octave (programming) help

    I'm currently undertaking a course in Solid State Physics and my professor has asked us to undertake some work in the free software 'Octave'. I have not had any programming experience in my life and I am feeling very much out of my depth. The lecturer gave us an initial file with the relevant...
  37. Y

    Octave programming - some advice for newbie

    Hi there - I am looking to get some help in programming with Octave. Trying to work out a random integer generator and well not really getting anywhere so far - I'm hoping someone can give an example or guide in terms of how I should go about doing it in Octave. Thanks
  38. qspeechc

    Upgrading Octave: Exploring the Newer Version on Campus

    Hello everyone. I recently had to use Octave on campus, and I noticed they had a newer version from the last time I used it. The interface is very much more like that of MATLAB's, with the history, file directory etc. on the left-hand side; but most importantly, it allowed you to have an...
  39. D

    Octave vs Decade: What's the Difference?

    Hi i was reading somewhere and i have found the following: loss: 6db/octave 20db/decade I know what db is but i don't know what octave is...
  40. U

    Need HELP getting started with octave.

    Hi, appologies if this isn't the best forum for this question, I'd like to get some help (or find out where to get help) on using the open source "octave" maths program. It's a very specific question, I have to find out how to allow included (library) functions to be able to access my user...
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