12th root of 2

The note relationships in a chromatic scale are based on the 12th root of 2.

An octave has a ratio of 2. An octave is divided into 12 equal steps.

For example, to find the ratio of one semi-tone (half step), on a scientific calculator, use this button:

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Here’s the result where x = 2 and y = 12

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In a computer program, you could use the pow() function calculate 2 to the 1/12 power. Here’s an example in javascript:

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This Max patch shows the relationships between any two notes and how to calculate the pitch of a note based on the semi-tone interval. You might use it as a starting point to design your own scales. For example, a 13 note chromatic scale.  Or relationships based on randomness.

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Download

https://github.com/tkzic/max-projects 

folder: 12throotof2

patch: 12throotof2.maxpat

cv.jit revisited

Jitter computer vision library

By Jean-Marc Pelletier

http://jmpelletier.com/cvjit/

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Several examples you can try by running the “help” files. All of the explanatory text below is by Jean-Marc Pelletier.

cv.jit.blobs.elongation

The utility abstraction cv.jit.blobs.elongation.draw superimposes elongation values on the image sent to its right inlet. You MUST also connect the output of cv.jit.blobs.moments to its middle inlet. You can use the attribute “frgb” to set the colour used.

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cv.jit.binedge

Marks as ON only pixels that are themselves ON and have a least one OFF neighbour. In other words, it returns only the edges in a binary image.

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cv.jit.blobs.bounds

cv.jit.blobs.bounds offers similar functionality to jit.findbounds but finds the bounding box for every blob in a labeled image.

cv.jit.blobs.bounds outputs a 4-plane 1-dimension float32 matrix whose number of cells is the same as the number of blobs in the input image.

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cv.jit.blobs.centroids

cv.jit.blobs.centroids functions much like cv.jit.centroids except that it takes for input the output of cv.jit.label and calculates the center of mass and area of each connected component individually.

The output of cv.jit.label must be of type char.

cv.jit.blobs outputs a single-row, 3-plane char matrix where the number of cells is the same as the number of labeled components.

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cv.jit.blobs.direction

cv.jit.blobs.direction is almost identical to cv.jit.blobs.orientation. It also takes in the output of cv.jit.blobs.moments and calculates the orientation of each blob’s main axis. However, unlike cv.jit.blobs.orientation, it takes into account symmetry. This means that cv.jit.blobs.direction can tell which direction a connected component is pointing.

Like cv.jit.blobs.orientation, the output is in radians by default and can be changed to degrees with the “mode” attribute. The output is between 0 and 2Pi.

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 cv.jit.blobs.moments

cv.jit.blobs.moments functions much like cv.jit.moments but computes moments and invariants for every blob identified by cv.jit.label. See cv.jit.moments for a discussion on moments and invariants.

The output is a 17-plane, single-row float32 matrix. The number of cells is the same as the number of connected components.

The output of cv.jit.moments can be fed to other objects for further analysis. See cv.jit.blobs.orientation, cv.jit.blobs.direction, cv.jit.blobs.elongation, and cv.jit.blobs.recon.

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cv.jit.blobs.orientation

cv.jit.blobs.orientation functions much like cv.jit.orientation except that it takes for input the output of cv.jit.blobs.moments and calculates the orientation of the main axis of each connected component individually.

cv.jit.blobs.orientation outputs a single-row, 1-plane char matrix where the number of cells is the same as the number of labeled components.

Orientation is measured in radians by default but you can switch to degree output by specifying “mode 1”. The values are between 0. and Pi radians, with the extremes being horizontal and Pi/2 vertical.

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cv.jit.blobs.recon

cv.jit.blobs.recon calculates the statistical distance between blob shape descriptors and a pre-computed model. The model must be created using cv.jit.learn, and cv.jit.blobs.recon functions much like cv.jit.learn’s “compare” mode.

cv.jit.blobs.recon must be fed the output of cv.jit.blobs.moments. Use the “mode” attribute to set whether moments (0) or Hu invariants (1) are used. Make sure that this matches the data used to train the model.

The output is a 1-plane float32 matrix, in which each cell contains the statistical distance between the corresponding blob and the model.. The lower the output value, the more similar the blob’s shape is to the model.

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Regenerative shortwave radio experiment

Circuit design by Ray Ring

http://circuitsalad.com/2015/01/27/yet-another-variant-of-the-junk-box-regen-this-one-is-really-weird-but-is-an-excellent-performer/

The audio is playing through headphones here, so you can’t hear the excellent signal quality

I didn’t have the OpAmp called for in the circuit, so I built this audio amplifier designed by Dean Segovis: http://hackaweek.com/hacks/?p=131

The antenna was a piece of wire about 30 feet long.

An air variable capacitor was used for tuning.

More to come…

Basis function generator

jit.bfg provides basis functions including various noise contours.

Here is yet another example co-opted from dude837 tutorial 30: https://www.youtube.com/watch?v=hoCpbxslvS8

This is a set of color bars composited with a noise gradient.

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Original components:

Colorbars

colorbars

Noise gradient function

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A few minor changes were made to the original patch, including addition of comments and presets.

Download

https://github.com/tkzic/max-projects

folder: bfg

patch: dude837-tut30-tz.maxpat

Physics simulation driven by audio

From tutorial 21b by dude837

https://www.youtube.com/watch?v=COl3ft1PPNU

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What’s different?

There was a problem with the spheres not returning to the resting position. They were constantly expanded outward. By removing the frame rate trigger from qmetro, and triggering only when audio data is received, the response was improved. You can also set signal amplitude going into the bonk~ object.

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Download

https://github.com/tkzic/max-projects

Folder: physics

Project: bumper-phsyics

External objects: bonk~ from: http://vud.org/max/

ep-341 Max/MSP – Spring 2015 week 9

Design a synthesizer is Max – Part 2

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Topics:
  • Waveform select
  • Recording
  • Polyphony
  • Presets
  • Max For Live
Click this link for Notes on Poly~, the topics above and patches for the synthesizer we built in class:
https://reactivemusic.net/?p=18573

Miscellaneous

The hi object: for reading human interface devices (like game controllers. Use the code in the Max help file to get started.

Boids sonification: https://reactivemusic.net/?p=18388

Random walk sonification: https://reactivemusic.net/?p=18455

Questions:

How would you design a patch to automatically select (trim) a sound from a buffer that contained silence and background noise as well as music?

How do you use wireless controllers, like a wiimote, with Max?

Assignment

Demonstrate M4L devices in class next week.

Basic synth in Max – part 2

Yet another Basic synthesizer design

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See part 1 here: https://reactivemusic.net/?p=18511

New features

Drag to select buffer start/end points

waveform~ object

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Sample recording

record~ object.

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How to design voice activated recording?

*Time compress/stretch

groove~ (Max 7 only)

Presets

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M4L preset management: https://reactivemusic.net/?p=18557

Polyphony

poly~ object

Polyphonic Midi synth in Max

https://reactivemusic.net/?p=11732

local: poly-generic-example1.maxpat (polyphonic)

Polyphonic instrument in Max for Live

Wave~ sample player: https://reactivemusic.net/?p=18354

local: m4l: poly-synth1.als (aaa-polysynth2.amxd)

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Max For Live

automation and UI design (review)

Distributing M4L devices

How to create a Live ‘Pack’

by Winksound

  • save set
  • collect all and save
  • file manager
    • manage project
      • packing : create live pack