I've heard there was a conventional debugger in the WorkBench. It is very old and apparently unmaintained. You can still download it but I was unable to get it to work in Eclipse.

There is a debugger function for notebooks, but it has very odd behavior and i was never able to get it to do anything useful.

I'll check your link tomorrow. Thanks. It seems a learning curve on 'all levels' :-)

Of course, you're right. I failed to check my copying. Something went wrong in the pasting.

I see what is the problem : In the Reply cell it is pasted all right, but in the 'Reply Preview' underneath that (which determines what goes into the post) the underscores are lacking. Also if I put the function in quotes.

If I tye in a underscore like this a_ it works. But F[x,a] does not. I have typed the two underscores but they are missing in the 'Reply Preview'.

Quite strange. Also CR are sometimes not registered in the 'Reply Preview'.

See attached screenshot

Attachments:

Screen Shot 2022...png

If you look here, https://community.wolfram.com/groups/-/m/t/270507, starting at the Post Editor section, you'll see better ways to post code fragments.

I tried it out with a simple Dynamic slider and you are right. I can enter the variable name and get the current value. The things is, that I had many occasions in more complex code, where I did not manage to get to the variable value in the normal way and the only way to see the value of the variable was to wrap it in Dynamic. That might have something to do with my original question :"What is the grey 'x' when I do not close a statement with a semi-colon. I do not know why I cannot see the variable value and I will have to wait until it occurs again to put my finger on it. I cannot find the occurances right now.

I reread the docs on Manipulate and Dynamic and if I understand it well, it seems to be as follows :

1. In a Manipulate the variables are local. So to see an variable from within the Manipulate, I have to pass it to the outside. Also to use it in a function outside the Manipulate.

2. This does not seem to be the case in a Dynamic.

3. In a DynamicModule, case 1. is the matter again (local vars).

I hope this is a not to simplified and more or less correct summary.

Eric, I've been thinking the same. It would be good if we could mail privately. I don't know how to do that, so I'll post a mailadres I have :

If you please, contact me on that address. I am really thankfull for your help.

It was a busy day for me today, so not much time.

About your answer 4.

I get the gist of it. I will need a manipulate / Dynamic for most of my applications, as they have to be interactive. I understand that I can paste my code, or parts of it into seperate cells, as to see how that part behaves. And I do that already.

In the next days, I will try to convert a more complex code I have working with Dynamic to Manipulate, to see if I can pull that off and if it works better for me.

One of the problems I forsee, is that functions ouside a manipulate cannot be called from inside the Manipulate itself, because of the variable scoping. That is also the problem I experience with Dynamic. If I want to see the value of a dynamic variable (aa) outside the Dynamic[], I have to use naother Dynamic[aa].

The way I used the Dynamic, was that I put it where I needed it and had 'normal' code in between. With Manipulate, as far as I see it (I might be wrong though), I need to do everything that is interactibve within the one Manipulate function.

I just tried to nest or combine two Manipulate[ ] , but that does not work. With Dynamic (and that was if I remember well, the reason I continued with Dynamic in stead of Manipulate) I can 'call back' on variables I have in an earlier Dynamic function. It gives me a better overview of my coding. One of the things I am still not used to is the extremely compact way of coding in WL. Proficient EWL coders put into one line of code, where I am accustomed to to the same with 10 lines. Of course I am more than willing to change my unelegant coding for a better one, I am totally not attached to my bad coding. But untill now it was the best I could do :-)

That Dynamic[ ] seems to keep it's variable values I discovered only later and gave me an additional bonus.

Anyway, I hope the weekend will bring me some free hours to experiment some more. I find it all very interesting (and frustrating all at times that I don't get it :-)

Thanks, Beat

I jusr read that in a Nb by Lou D'Andria, Senior UI Developer, Wolfram Research which is from a webinar he did on Manipulate earlier this year I believe.

I must say, that some of the code in the Nb does not work, I found out, so my 'quoting' his work might be wrong.

(2) Right. To tweak things, you'd just change the variable initializations at the beginning of the DynamicModule. It's just another tool. I wasn't entirely clear what you meant by "retain settings", so I'm just giving you lots of things to play with.

(3) I don't really expect you to in this case. With will make the variables constant/unchangeable, so you would have a static snapshot. Maybe not worth worrying about.

(4) Okay, if this isn't working for you, this may be the source of all of your troubles. I suspect this is why you started using Dynamic. What I'm suggesting here is what folks are probably doing 99% of the time. The notebook itself is the "playground". You don't need Dynamic, DynamicModule, Manipulate, etc to just start playing around with expressions in a notebook. I probably should have added more instructions. The body of the Manipulate will have variables in it, and those variables are sort of declared/initialized with all of those bracket expressions at the end (after what I'm calling "the body"). If you paste just the body into a separate cell, all of those variables will now be undefined (they're now in the Global scope instead of localized to the Manipulate). So, you'll also need to provide values for those variables (presumably in more cells that get executed before the "body"). Maybe I'll put together a whole notebook to demonstrate. But probably not today.

Another thing is, how can I get the Graphics outside the Grid.

The body of the Manipulate can be any Mathematica expression, so it could be a CompoundExpression. So, you could just do something like

Grid[<debug stuff>];Graphics[<graphics stuff>]

This will suppress the debug stuff. When you want the debug stuff, you'll need to comment out the ;Graphics[...] bit (including the semi-colon). You could also add another Manipulate variable, like debug and then wrap the whole body in an If (showing whatever you want if debug is True and just the Graphics if debug is False). Or, you could wrap the debug stuff in Print. Or... <there's no end to how you might want to handle this>.

You used a comma instead of a semi-colon. Also, you left the Grid in an invalid structure, so if you got rid of the graphics part the grid part wouldn't display correctly.

I got it working now. I put the Graphics again inside the Grid[ ] which is ok. I can now comment out the variables and values. Quite neat :-)

I did not manage do get the Grid with variables with the Graphics ouside the Grid[]. But all right. Sometimes I find it hard to put the different brackets in the right place.

I will now see what I can do with your advice on retaining the Settings when I run the script again.

Yes I did :-) I got the Graphics ouside he Grid[] working, but could not see the stuff inside the Grid anymore.

So now I have put the Graphics inside the Grid[] again and can comment out the values if I want to.

I could not figure out so far, how to seperate the two (Grid[] and Graphics) and have BOTH of them working. I seem to get trapped in little snags all the time. As I am quite persistent, so I will eventually get there. But sometimes it feels a bit like leaning Finnish. Anyway, thanks so much for all your wonderful help, Eric. I really appreciate it.

Eric, thank you for your extended effort.

I like the way you have implemented a kind of Debugger (in the Grid form). I was missing that and the way I tried to do it, to erase the semicolon on lines I wanted to check the output, which in a Dynamic wrapper does not work well.

I had never used With, which is useful and clear to me. Great.

I played a bit with your example and I understood it. I also made the showPoints working and beautified the thing a bit. Just playing around to see if I get it.

Still I have some questions :

The values I set with the sliders and buttons are not retained, the next time I run the script. As I am working with RandomIntegers[100] instead of in the example fixed xCoords & yCoords, I need to run the script often, but would like to retain the settings. This I have working with the script using Dynamic.

Another thing is, how can I get the Graphics outside the Grid. I tried in several ways, but get either warnings in my script or when I run the script, like this :

Manipulate::vsform: Manipulate argument {} does not have the correct form for a variable specification.

I would like to have the Graphics outside the Grid, so I can comment out the Grid entirely when things are working.

I attached my ‘work’.

Thanks again :-)

Attachments:

Eric Rimbey mani...nb

Wonderfull,Eric. I am studying your example at this moment. It might take a little while to answer. I first want to understand your code completely. Also, I will again read again about Manipulate versus Dynamic :-)

I understand that now, but something like that is Not to found in the Help. I have been breaking my head over it, as it is not consistent with WL behavior in other cases.

And for that specific example, I personally wouldn't have gravitated toward a For loop but instead toward some List restructuring/combining strategy like Riffle.

I agree, but sometimes I do and sometimes I don't manage to make the code in the "Mathematica-way". Here I just didn't succeed and also wanted to at least master the For function. You know, I am an artist and the programming is to get new ideas into my work. So for me it is more important to have some code running properly than that it will win a beauty- or efficiency price. I like to learn and make better code, but in the meantime I produce some real ugly, but at least working code :-)

Thanks again for your help.

Set::write: Tag First in First[numPoints] is Protected.

Set::write: Tag Last in Last[numPoints] is Protected.

As for these errors, they're actually pretty self-explanator, although you do need to understand Mathematica's computation model. You have this line:

First[numPoints] = 1

This is trying to set DownValues for First. But First has the Attribute Protected (as is typical for built-in functions/symbols). So, to avoid the error, you'd either need to Unset that Attribute (bad idea) or set UpValues for numPoints (won't do what you actually want) or initialize numPoints as a List before you start setting its elements using syntax like this: numPoints[[1]] = 1 (but this also doesn't seem to be what you want just based on what I can infer from your variable names).

Yes, now it is ok. I hope I remember for next time :-)

I attached a Notebook as example, but now I see my response, it looks very strange. The code is inline and the Nb is not as an attachment. Sorry, I have done it right I thought : I used the button "Add Notebook" and browsed to my Nb and clicked 'Add' whatever was asked.

I found the Debugger. Looks very unfamiliar to me, but I will study it first, before asking more :-)

I tried again to attach the Nb. Again the same strange effect. The code is inline in the message and at the end is a very long pink rectangle (error output), which is not in my Nb.

I don't get it. How do attach a Nb properly?