Joji Iwasaki

Background: I was trying to write a binary search algorithm in GenExpr.

Issue: In the attached patch, if "right" is removed at line 16 of [codebox] in [gen~], an infinite loop occurs.

lower_bound(buf, val) {
	left = 1; // Buffer is 0-based
	right = dim(buf);
	
	while (left < right) {
		mid = int((left + right) / 2);
		
		if (peek(buf, mid) < val) {
			left = mid + 1;
		} else {
			right = mid;
		}
	}
	
	// For some reason, removing right causes an endless loop.
	return left, right;
}

Buffer buf("buf");


out1 = lower_bound(buf, 2);

causes an infinite loop. Am I missing something fundamental?

lower_bound_test.maxpat

Background: I was trying to write a binary search algorithm in GenExpr.

Issue: In the attached patch, if "right" is removed at line 16 of ... 

strange-behavior-of-while-loop-in-genexpr

Update: I haven't found a solution, but whatever it is, I found the cause: removing `right` from return seems to prevent the else block from compiling. Here is an excerpt of the exported C++ source:

inline void lower_bound_buf_i(Buffer& buf, int val, int& out1, int& out2) {
    int left = ((int)1);
    int buf_dim = buf.dim;
    int buf_channels = buf.channels;
    int right = buf_dim;
    while ((left < right)) {
        // abort processing if an infinite loop is suspected;
        if (((__loopcount--) <= 0)) {
            __exception = GENLIB_ERR_LOOP_OVERFLOW;
            break ;
            
        };
        int mid = int(((left + right) * ((t_sample)0.5)));
        bool index_ignore_1 = ((mid >= buf_dim) || (mid < 0));
        // samples buf channel 1;
        t_sample peek_106 = (index_ignore_1 ? 0 : buf.read(mid, 0));
        t_sample peek_107 = mid;
        if ((peek_106 < val)) {
            left = (mid + ((int)1));
            
        } else {
            right = mid;
            
        };
        
    };
    out1 = left;
    out2 = right;
    
};

The above is the source with`right`. But, without `right`:

inline int lower_bound_buf_i(Buffer& buf, int val) {
    int left = ((int)1);
    int buf_dim = buf.dim;
    int buf_channels = buf.channels;
    int right = buf_dim;
    while ((left < right)) {
        // abort processing if an infinite loop is suspected;
        if (((__loopcount--) <= 0)) {
            __exception = GENLIB_ERR_LOOP_OVERFLOW;
            break ;
            
        };
        int mid = int(((left + right) * ((t_sample)0.5)));
        bool index_ignore_1 = ((mid >= buf_dim) || (mid < 0));
        // samples buf channel 1;
        t_sample peek_118 = (index_ignore_1 ? 0 : buf.read(mid, 0));
        t_sample peek_119 = mid;
        if ((peek_118 < val)) {
            left = (mid + ((int)1));
            
        };
    };
    return left;
    
};

Oh man, the else block is missing! Does anyone know why this happened?

Strange behavior of while loop in GenExpr

Tarik Barri

I must be overlooking something insanely obvious, but I can't figure out what.
This gen code:

getOne() { return 1.0; }
getOneIndirect() { return getOne(); }
if (getOneIndirect() == 1.0) {
  out1 = 1.0;
}

...fails to compile, and gives me the error message:gen_domain: dsp.gen: [string "gen2.dsp.Model"]:1687: attempt to index local 'instance' (a nil value)

(EDIT - this refers to the 'gen' object, not the 'jit.gen' object)
I've reproduced on several max versions and two computers, but can not find this issue mentioned anywhere online.

Any hints as to what's going on would be greatly appreciated
-t


I must be overlooking something insanely obvious, but I can't figure out what.
This gen code:
getOne() { return 1.0; }
getOneIndirect() { ... 

impossible-to-use-returned-value-from-function-in-if-statement

Hi Tarik,

I just added an else block and it works fine. 

I see, it's the "jit." that made it compile, not the 'else' statement.

The moment I remove the "jit." prefix and it becomes a regular 'gen' object, it stops compiling. So without wanting to jump to conclusions, I am tempted to go with the hypothesis that 'gen' is basically broken for now?

gen~ (with the tilde) seems to be slightly more robust than gen, but also this fails to compile when I get a bit deeper into conditionals:

and here's another amazing bug. Once this empty for loop is present, the output simply stops functioning (in both gen and gen~), so that this two line code doesn't work.

for(index=0; index < 1; index+=1) {}
out1 = 1.;


I can't possibly be the first one to run into all this weirdness, so maybe someone who's gone through this can tell me how they deal with these issues? 


Hi Tarik! 

I copy pasted your code into a codebox in jit.gen and it gives me exactly the output you would expect, without compilation errors. 

In "gen" instead it gives me the error you mentioned. 

Sounds like a bug, I will report it

Hey Tarik, so great to see this discussion here, my 2cents:
They do indeed need to work on making the max-window error messages from gen~/gen/jit.gen a bit more useful/helpful to us 🙏

seems like your code should work, i even tried adding a superfluous argument to the functions like the 'p' in the functions for Gregory's article here, as well as tried saving to a .genexpr file and instantiating using 'require'(thinking maybe it might compile differently when in an extraneous .genexpr file), still didn't work, even though Gregory's functions seem to have the same basic structure:
https://cycling74.com/tutorials/gen~-for-beginners-part-7-creating-reusable-tools

(also tried all those steps in both gen and gen~, couldn't get it to work)

i do know that 'gen'(without the tilde) handles scheduling and memory differently('gen' needs to be triggered from outside, or have internal metro on using '@active 1'... also cannot use things like 'buffer' but still can use 'data' instead), so maybe better off trying things in gen~ first.

i dunno... i tried, hopefully it at least helps whittle out some testing(maybe also posting Gregory's article can help you find some thread of similarity to follow).

Thanks both!!

I've now found that if I take the functions of which I want to test their outputs in an 'if' statement, and store the results of these functions in a 'History', I can use these functions. So:

getOne() { return 1.0; }
getOneIndirect() { return getOne(); }

History enableFunction(0);
enableFunction = getOneIndirect(); 
	
if (getOneIndirect() == 1.0) {
  out1 = 1.0;
}

...and if I want to do this with functions which take variable arguments, I need to use these same variable arguments when storing the results in the 'History', otherwise it will still fail.

The thing that most confuses me about this all though is not the bug itself, but the fact that it seems as if I'm the first one to ever try using returned function values in an 'if' statement. Which surely can't be true. I'm not that totally unique and special, or...?

the reason why your genbug2 patch creates silence is due to the code generated from your GenExpr code inside the Codebox - whereby its not yours code fault.

If you open the "code" sidebar of the gen (gen~, jit.gen, jit.gl.pix) patcher - the stylish C in the right hand toolbar -  you can see that the "code generator" has set out1 & out2 to 0 ... hence silencio ;-).

I also currently experience "gen code generation" weirdness, where an else block is just "optimised away", but that happens in the jit.gen.

But I guess, wheter audio or video domain, there is only 1 code generator that not only translates the "normal" gen operator patches, but also the GenExpr Code we type into Codebox into an intermediate GenExpr Code that its visible in the "code sidebar".

So if you experience weird stuff, the code sidebar is the place where you might detect THAT something weired / wrong was generated from your code.


Yes actually I noticed this too and this can help indeed. Not with the other errors unfortunately. But this 'history' hack I described above seems to make things work... for now...

Impossible to use returned value from function in if-statement?

Agustin Spinetto

I did this video tutorial where I show how to adapt a PM cross feedback maxpatch from the book Generating Sound & Organizing Time by Graham Wakefield and Gregory Taylor and flash it into the Electrosmith Patch:init submodule. 

This can be used as an example for anyone who is starting to program with Max gen~ (like me) and want to learn how to adapt Gen~ examples to flash them into Electrosmith's patch:init  so this module becomes fully functional with the rest of the Eurorack's modules.

I also explain how to control the pitch of the synth module from with an external CV instrument (V/Oct input) or sequencer, something that I couldn’t find how to do it. I have also included an adjustable envelope to the patch.  Thanks @Takumi_Ogata for the help.

It is my first tutorial, I hope it would be useful for someone. Thanks a lot!

The patch: https://drive.google.com/drive/folders/1gHlMakJCdZ6XcWtS8fjJOktItPMCDnid?usp=drive_link

Creating a custom Synth Module using Max

I did this video tutorial where I show how to adapt a PM cross feedback maxpatch from the book Generating Sound & Organizing Time by Graham ... 

pm-cross-feedback-sound-module-into-patchinit-with-voct-and-envelope

PM cross feedback sound module into patch:init with V/Oct and envelope

kokiki

hi, i'm struggling with a probably very simple problem to solve: i'm trying to convert this patch, from the book "generating sound and organizing time", from visual patch to code. the general functioning of the patch seems to me to have got it right, but I don't understand where I have to put the noise() function in the codebox to prevent it from entering the audio band. any help will be greatly appreciated! on the left there is the visual one, and on the right the code one...

prova_prova.maxpat

hi, i'm struggling with a probably very simple problem to solve: i'm trying to convert this patch, from the book "generating sound and ... 

patch-to-code-conversion

patch-to-code conversion

I am working with the "generating and organizing .." book. 
My expectation of using the gen abstractions of the book was to just type away and get a proposal to select from, but that is not the case.

I checked the file preferences search path and everything seems to be ok, but I need to type out the complete name of the go lib abstractions to use it.

Do you know what I might have overlooked?

Thx in advance!


hi together,
I am working with the "generating and organizing .." book. 

go-library-not-recognized-as-expected

Put the abstractions file in, say, the Packages folder on your machine.

thanks for your reply. it already lives exactly there and I thought I just could start to type "go. ..." and I would get some suggestions, but this is not the case.
Could it be something different other than the location / filepath?

go library not recognized as expected

proppjones

Howdy I am still a beginner and recently purchased  Generating Sound and Organizing Time by by7 Wakefield and Taylor.  Very interesting stuff.  My problem is this I downloaded the sample patches. so far so good, I opened  a sample patch: Counter_simple_timer and started adding  objects. When typing history I get history-history :No such object.   I am at a loss


Howdy I am still a beginner and recently purchased  Generating Sound and Organizing Time by by7 Wakefield and Taylor. 

history-object

'history' op is specific to gen~, you can only add it within the 'gen~' subpatcher of your patch.
there are different parts to the environ: Max, MSP, and Jitter, (they handle event/data-flow, audio, and video respectively), that make up the larger environ of Max, and within each you can use 'gen' for different/more-specific tasks: there is 'gen' for event/data, 'gen~' for audio, and 'jit.gen' for jitter matrices(there's no 'history' op in jit.gen either).
it's probably best to go through the tutorials for Max proper, first, before learning gen, i recommend the MSP ones, too for audio-specific stuff:
https://docs.cycling74.com/max8


and then, to learn the 'history' op most comprehensively, it's best to try it within the audio realm of 'gen~'(so you can double-click on the 'gen~' object to go inside and then add from within there). hope it helps 🍻




Thank you, very much this does indeed help.


History object

flaviogaete

I hope it's OK: I'm starting a new post afresh to tackle/study the topic of smoothing control signals in gen~. I'm picking up/consolidating from a couple of posts that have a lot of useful info on this:

https://cycling74.com/forums/parameter-smoothing-in-gen 
https://cycling74.com/forums/translate-msp-line-into-gen-counter 

If there are any other useful posts that I've missed please kindly let me know.

I've gone ahead and compiled the various examples into a patch for easy comparing:

In this patch, you'll find:
- Gen example "dynamic smoothing"
- 1Pole filtering signal (I think? Or some equivalent thereof)
- A couple of 3pole variations
- A "line" example
- A "slide" example

(Thank you everyone who has contributed to this BTW! Super useful stuff!)

I have a couple of observations/questions then:

1 - Are there other examples or techniques that I may be overseeing worth including in this study/discussion?
2 - My personal concerns (for finding "the ideal object to use", though I understand that these may be implemented in a plethora of applications) are for real-time, i.e. human-made, sweeps, etc. (I haven't yet delved into what the needs might be for generative applications) -- be it volume changes, filter sweeps, pitch bends, what have you. With that said, my priorities for choosing are:
- How "musical" are the changes in sound?
- How CPU-demanding is the object?
In that context (I hope this is helpful for others), I found the 3-pole to be the more "musical" one (e.g. doing slow, soft fades, thinking of phrasing, etc.); the "slide" example, the 'cheapest/simplest' implementation/compromise (though I wouldn't know how much of a difference there is with the other types, in terms of CPU requirements); the "1pole" and "dynamic" examples were still "zippery", but perhaps one could spend more time tweaking them (especially the "dynamic" one).
3 - Is there a way to test the CPU performance of a particular object/algorithm? I know of "adstatus cpu", but with a current Mac that's kind of a moot point as it just reads "0"; I'm more concerned about developing for other users who might not be able to afford the fastest computers, etc. I guess I should do my search on this topic in the forum, but if anyone has any pointers, it will be much appreciated!

I think that's it for now. If anything else comes up (questions or new discoveries), I'll see to edit this post. I hope this is helpful!

Hi there,
I hope it's OK: I'm starting a new post afresh to tackle/study the topic of smoothing control signals in gen~. 

control-signal-smoothinginterpolation-in-gen~

Control Signal smoothing/interpolation in gen~

enki

[Begin Shame] I'm trying to understand vector components via equations (gasp!.. I know, I know "equations are mathematical crutches!" and I risk being shunned by the cult..but I'm so old I've forgotten most algebra, so please humor me). Is the Red box represented correctly by this equation in grapher? If not what would be the correct representation in grapher?  What would be the component equation for the cosine term? [Blue region.] Also what happens when swiz x and Param Time both get multiplied by 3...is that an  f(x,t) thing? Is there a limit to how many parameters can be attached to a multiplier?  See attached image. You don't have to show a grapher image, any image with a (ghastly) equation will due. [Tangentally and most offensively, why are equations so ardently ignored in this cult..I'm talking to you Federico..maybe even Sam..as a youth were you given an equation swirly by Gottfried Leibniz's great great great once removed second nephew, and only escaped via a tangled morass of spaghetti? We of the cult, wonder..sometimes. [EOS]] *Feel free to include the full Vector equation for out 1. [Red should be 8 not 18 -Thanks Luvlongtime/FMJ.]

Screen Shot 2023-05-15 at 11.42.51 AM.jpg

[Begin Shame] I'm trying to understand vector components via equations (gasp!.. 

gen-equivalent-vector-representation-in-grapheralgebra-"oh-the-shame!"

red looks correct. 
what are you wondering about blue? isnt it almost the same?

(watch out, unlike in gen~ or max, in MSP you would have to use sinx~, as sin~ is not a trigonometric operator.)


Meh, math is overrated anyway. :p I mean isn't it all just multiplication, division, addition and subtraction? And clever ways to combine them? 

Shouldn't it be 8 instead of 18? And "time" is useless here if i'm not misstaken, connect after [norm] and modulo it by 1. Time should be between 0. and 1.

Red: y = 2sin((8x)PI)
Blue: y = 4cos((3x)PI)

Edit: "And "time" is useless here if i'm not misstaken"
Never mind i think it will "add" time to the output from norm? I only use two inputs going into the same inlet in Dsp though

Yeah, your probably right about math, we could just use hand gestures. It's mostly handwaving with chalk anyway. After the dust settles what do we really have..maybe some pretty pictures, but we had pretty pictures before math (I'm looking at you Lubang Jeriji Saléh cave). Take look at the blue region..no one on this forum seems to know what "equation" that might be. Somehow it's still a mystery. 

math is where the fun begins, especially if you´re bad at it (like me.)

i mean i am using "cos(pi/8)" in a regular matrix encoder where you could as well write "0.92" like in the orignal paper from 1972. not to speak of the precision of analog components from that period. 
but when i can do it more right than right, i do it more right.

and the patch must look nice. because if it does not look nice, it is not finished.


Hey Enki, very far from being a math wiz myself, but it looks like the answer from luvulongtime is exhaustive. 

If you wish to move the wave using the "time" param you should connect the time after the [* pi], unless you want the time to be multiplied by PI as well, which is probably not the case. 

Also what happens when swiz x and Param Time both get multiplied by 3...is that an  f(x,t) thing?

in gen when you send two outlets to the same input they will be summed together. 
So in your snippet the result of the sum will be multiplied by 3. 

Regarding why equations are ignored,  not sure I understand what you mean.
Max is completely based on numbers, so on math, pretty impossible to not deal with equations of any sort : ) 

Edit: sorry I probably misunderstood the equations part. You were probably referring to the mathematical notation for equation, while in programming (like Max) we mostly deal with expressions and not the equation math notation. 

I can see how some tutorials on how to translate math equations to max or gen expression could be useful. 
Cheers!

Gen equivalent vector representation in Grapher/algebra ("Oh the shame!")

Da Xu

I see in quite a few of the Gen book examples, there having a sub patch called "p building"

What are those for? 

question-about-gen-book-example

Those patches labeled p building or those with several patches together (labeled "Step by step") provide a chance to show you how a more complex patch is built step-by-step; it's often the case that the sequence of patches track the illustrations in the book for building the "final" version of the patch. It's generally the case that each further iteration of the patch adds a single new feature, which may mean that those patches have everything you need for your own patching and nothing you don't need....

Question about Gen Book example

Jan M

I just started to get my head around [jit.gen] . Do input and output matrices always have the same dimensions and plane count, or ist it possible to to change/re-arrange a matrix.

In my case I am working on small matrices performing trigonometric calculations.
Can I transform an input matrix with one plane and the dimensions 6 x1
to a matrix with two planes and the dimensions 2x1? 

The first three cells of the input matrix  shall be mapped to the first cell of the output matrix (onto three planes) - and the same for the last three cells of the input matrix to the second cell of the output:

Input:
|--------------------------|
| a  | b | c | d | e | f |   -> plane 0
|--------------------------|

Output:
|---------|
| a | d |  -> plane 0
| b | e | -> plane 1
| c | f | -> plane 2
|---------|

change-matrix-dimension-and-plane-count-inside-jit-gen

Jan, the left input sets the dim, planecount and data type for all inlets and outlets.


I was aware of this - but whatever i set as dimension or planecount attribute (even with adapt set to 0) the output format seems to be always the same as the input format. Is there a way to have different input and output  dimensions and planecounts? I am not really a natural in matrices - maybe that's something completely of the idea of matrix calculation ....


jit.repos should do what you're after.  I don't think it's possible in jit.gen.


Jan, my understanding is that jit.gen can have n inlets/outlets but they all have to be the same size as the left inlet.  Hence, the thinking is a bit backwards.  In terms of size, you need to give it what you want.. rather than giving it something else to make what you want.  If that makes sense.


it does.  And actually right now I realize that this it what is described in the help file : "...generates new  Jitter Matrix Operator objects". It is for matrix operators not to transform matrices. So for transforming a matrix i'll have to stick to plain jitter objects.

You can work with different dimension matricies - BUT, the output will always maintain the same attributes of the matrix entering in [jit.gen]'s first inlet.

The great bit about this is that you don't even need to use that matrix in any calculations; you can just bang a blank matrix that matches the format you want your output to be and trigger your calculations.

Modulo [%] in combination with [/] into [int] will be your bread and butter when you're translating between matrix dimensions.


Here is an elegant way of doing what you want :)

But there is still useless calcuations, I was expecting to find something more powerful


This technique is usefull when you want an audio signal to set the XYZ position of an array of 3d points. I had the idea by watching the patch 22.CatchNurbs in the JitterRecipes. In the exemple patch I'm mentionning I didn't like the use of messages send to a matrix object so I did it a way so you don't have to send any messages.


Alternatively,
you could do the same thing with "jit.coerce" (check example).
Combined with "jit.scanwrap" and "jit.dimmap" or "jit.transpose",
you can solve most matrix "conversion/re-organization" problems.

Thank you so much for clarifying jit.coerce – I had been attempting to solve dim/plane-remapping using codebox to no avail and this opens up to super-sustainable methods. 

Cycling '74 Forums

Update: I haven't found a solution, but whatever it is, I found the cause: removing `right` from return seems to prevent the else block ...

Yes actually I noticed this too and this can help indeed. Not with the other errors unfortunately.

I did this video tutorial where I show how to adapt a PM cross feedback maxpatch from the book Generating Sound & Organizing Time by Graham ...

hi, i'm struggling with a probably very simple problem to solve: i'm trying to convert this patch, from the book "generating sound and ...

hi max, thanks for your reply. it already lives exactly there and I thought I just could start to type "go.

Thank you, very much this does indeed help.

Hi there, I hope it's OK: I'm starting a new post afresh to tackle/study the topic of smoothing control signals in gen~.

Hey Enki, very far from being a math wiz myself, but it looks like the answer from luvulongtime is exhaustive.

Ahh got it. Thank you!

@Gussi Thank you so much for clarifying jit.coerce – I had been attempting to solve dim/plane-remapping using codebox to no avail and this ...