I need to exorcise my computer from voodoo
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in all seriousness, I just got done with tackling a similar debugging issue. Sometimes the debugger just isn't enough. As another commenter pointed out, the algorithm doesn't usually make much sense to people once it's at the point where it breaks. So you should write more code. I dumped intermediary LALR tables to CSV for example so i could visualize them. I also made symbols and grammar rules print out string representations of themselves to the debugger to help. In the end, write MOAR CODE until the problem reveals itself. Sometimes using graphviz can help, in extreme cases.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
That's how I have solved some knotty issues with a Python bouncy ball simulation I have been writing(just because I wondered what all the hype about Python has been). I created a logger class and wrote all the data out to a tab delimited file. I then found fairly quickly where the issues were - as rather than see isolated data, which is what debugger information tends to present, I was able to see data over time and solve the problem from there.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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That's how I have solved some knotty issues with a Python bouncy ball simulation I have been writing(just because I wondered what all the hype about Python has been). I created a logger class and wrote all the data out to a tab delimited file. I then found fairly quickly where the issues were - as rather than see isolated data, which is what debugger information tends to present, I was able to see data over time and solve the problem from there.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
Frankly, I solved that by not coding in python =P It's a magical language in some ways, but the grammar was designed at gunpoint. Who uses tabs to dictate program flow? I protest the language out of my distaste for poor grammars /grammar nazi
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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Yeah I made (some tiny bit) of progress lately.. because I wrote plenty of tools and visualisation to make the issue more understandable... I am getting close.. When it fails I got 3 intersection between 2 shapes (best understanding, so far, about the problem) now I *just* have to find out why! :laugh: :~ That can't be.. I guess I misdiagnosed a touch for an intersection.... That's a tricky one, since intersection are approximation though...
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
I'm building a parser generator right now, so if you know what that entails, you know I mean it when I say I feel your pain, neighbor.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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Frankly, I solved that by not coding in python =P It's a magical language in some ways, but the grammar was designed at gunpoint. Who uses tabs to dictate program flow? I protest the language out of my distaste for poor grammars /grammar nazi
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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Frankly, I solved that by not coding in python =P It's a magical language in some ways, but the grammar was designed at gunpoint. Who uses tabs to dictate program flow? I protest the language out of my distaste for poor grammars /grammar nazi
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
Once you get used to it, the spacing makes a lot of sense. I find it easier to follow programme flow with the indentation.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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Once you get used to it, the spacing makes a lot of sense. I find it easier to follow programme flow with the indentation.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
most people indent. write a python parser, then we'll talk about "getting used to it" when you have to make the grammar (including the tokenizer) context sensitive in order to handle significant vs insignificant whitespace.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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Quote:
Who uses tabs to dictate program flow?
A thing I'm asking me all the time.
It does not solve my Problem, but it answers my question
i mean, it's one thing to use tabs to show program flow, but they should be descriptive, not prescriptive.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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i mean, it's one thing to use tabs to show program flow, but they should be descriptive, not prescriptive.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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most people indent. write a python parser, then we'll talk about "getting used to it" when you have to make the grammar (including the tokenizer) context sensitive in order to handle significant vs insignificant whitespace.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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i love your signature by the way. it's too real.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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i love your signature by the way. it's too real.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
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Use the debugger! What a novel idea! :laugh: The problem with stepping through the whole algorithm manually is that there is too much data and raw numerical values don't make much sense to human eyes... it describe 2 potatoes intersection.. but when I look at the bezier's handle point values, it means little to me (except visually..) FYI, trying to debug this vector graphic eraser [issue](https://ibb.co/Ydf8yqg) :(( Anyway, just made a tiny bit more progress... In my structure I got, for some reason, an odd number of intersection (between 2 shapes)... :wtf: :confused: 333!
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
Super Lloyd wrote:
it describe 2 potatoes intersection
That explains it. Your computer's got the wrong chips.
I wanna be a eunuchs developer! Pass me a bread knife!
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I'm building a parser generator right now, so if you know what that entails, you know I mean it when I say I feel your pain, neighbor.
When I was growin' up, I was the smartest kid I knew. Maybe that was just because I didn't know that many kids. All I know is now I feel the opposite.
I have used a few of them, they are good! :) They are also tricky beast! :~ Good luck with that! :) And thanks for the support! ;P
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
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Super Lloyd wrote:
it describe 2 potatoes intersection
That explains it. Your computer's got the wrong chips.
I wanna be a eunuchs developer! Pass me a bread knife!
:laugh: Ha! Forget 586! Sour cream and chilly is the way of the future! ;P
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
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I have been working on and off (at home) on that single algorithm for almost 2 and half years, I think. I am now very close to completion with an elegantly simple algorithm :) Except.. it doesn't work... After days of staring at my screen I came up with a test that shows an internal data inconsistency that will predict failure. But... basically the validation is a loop doing some calculation at each step.. . It came literally right after the same loop applying the calculation result.. yet it has different value than expected?! Why, ho why? And how? :(( :(( I think the forces that be are preventing me from finding the truth! :o That's the only logical explanation I can come up with! Need exorcism ASAP! :mad: :rolleyes: :wtf: :~
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
Seems to me you have an ID problem here. I will try to explain. When your eraser tool, which is nothing but a circle object intersects with the existing object it creates new vertices. Those new vertices need to be connected to existing ones. During this process an AREA needs to be defined within the connections will happen. Since you have no area defined, newly formed vertices connect to the existing ones. Since no more than 2 vertices can be connected on a 2 dimensional object, an existing connection is broken splitting the object in 2. Here's how this happens: there's a vertex at the top left of your image where the breaking happens, and let's label it V1, and it's connected to a vertex below it, so let's label that one V2, and there's a Bezier curve that connects them. When you introduce the eraser tool (which is a new circle object that also consists of vertices) and intersect it with the object, you are creating new vertices, so for easier understanding let's say 2 new ones, V3 and V4. As a result, instead of new vertices V3 and V4 being connected and creating a Bezier curve between them, connection at V1 breaks, a new connection is created between V1 and V4, also between V2 and V3 thus splitting the object in two, and also creating a Bezier curve as it was their last state. The best way to approach this problem is to create 2 new states for each vertex: - is a vertex being deleted cause intersection happens where the vertex is, and 2 new vertices are created and connected thus eliminating the first one, - if the intersection doesn't happen where the new vertex is, newly created vertices should be connected to the nearest left, between themselves, and nearest right, following the edge of the object. Proposed solution This is just a rough idea on what's going on and what the solution may be. I hope I helped.
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Seems to me you have an ID problem here. I will try to explain. When your eraser tool, which is nothing but a circle object intersects with the existing object it creates new vertices. Those new vertices need to be connected to existing ones. During this process an AREA needs to be defined within the connections will happen. Since you have no area defined, newly formed vertices connect to the existing ones. Since no more than 2 vertices can be connected on a 2 dimensional object, an existing connection is broken splitting the object in 2. Here's how this happens: there's a vertex at the top left of your image where the breaking happens, and let's label it V1, and it's connected to a vertex below it, so let's label that one V2, and there's a Bezier curve that connects them. When you introduce the eraser tool (which is a new circle object that also consists of vertices) and intersect it with the object, you are creating new vertices, so for easier understanding let's say 2 new ones, V3 and V4. As a result, instead of new vertices V3 and V4 being connected and creating a Bezier curve between them, connection at V1 breaks, a new connection is created between V1 and V4, also between V2 and V3 thus splitting the object in two, and also creating a Bezier curve as it was their last state. The best way to approach this problem is to create 2 new states for each vertex: - is a vertex being deleted cause intersection happens where the vertex is, and 2 new vertices are created and connected thus eliminating the first one, - if the intersection doesn't happen where the new vertex is, newly created vertices should be connected to the nearest left, between themselves, and nearest right, following the edge of the object. Proposed solution This is just a rough idea on what's going on and what the solution may be. I hope I helped.
Actually, you know what? I think I found it! When I got this
| | ==+==+== \\\\\_/Sometimes I have to merge vertex when they are separated by very small interval, otherwise I got algorithmic issue... (like never ending loop calculating approximate intersection) But when I merge the intersection above, they become a touch.. i.e. the merge point is NOT an intersection anymore.. but I dunno it, all I know (at the moment) is a point with 4 line convergent on it, must be an intersection, right? I have to take that into consideration! Woa,.. good find.. will implement that later! :D (got othe rthings to do! :D )
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
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Actually, you know what? I think I found it! When I got this
| | ==+==+== \\\\\_/Sometimes I have to merge vertex when they are separated by very small interval, otherwise I got algorithmic issue... (like never ending loop calculating approximate intersection) But when I merge the intersection above, they become a touch.. i.e. the merge point is NOT an intersection anymore.. but I dunno it, all I know (at the moment) is a point with 4 line convergent on it, must be an intersection, right? I have to take that into consideration! Woa,.. good find.. will implement that later! :D (got othe rthings to do! :D )
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
I deal with this a lot in 3ds Max. Perhaps you could take a look how editable splines work, and that may be of help.
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I have been working on and off (at home) on that single algorithm for almost 2 and half years, I think. I am now very close to completion with an elegantly simple algorithm :) Except.. it doesn't work... After days of staring at my screen I came up with a test that shows an internal data inconsistency that will predict failure. But... basically the validation is a loop doing some calculation at each step.. . It came literally right after the same loop applying the calculation result.. yet it has different value than expected?! Why, ho why? And how? :(( :(( I think the forces that be are preventing me from finding the truth! :o That's the only logical explanation I can come up with! Need exorcism ASAP! :mad: :rolleyes: :wtf: :~
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
It happened to me once and i had a too long time to discover the problem. i was using ADO.Net, and connecting a textbox.text to a field in the table, and that field is int16, and i was trying to save into it an int64, and while the number value is small, but still, the textbox did not have its text changed, it always stayed a null. after the yoricka came :-D , i changed/or casted the int64 to int16, and it worked. so, check if there is a conversion happening here or there. Regards.
___________________________________________ May god give u good health and knowledge.
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It happened to me once and i had a too long time to discover the problem. i was using ADO.Net, and connecting a textbox.text to a field in the table, and that field is int16, and i was trying to save into it an int64, and while the number value is small, but still, the textbox did not have its text changed, it always stayed a null. after the yoricka came :-D , i changed/or casted the int64 to int16, and it worked. so, check if there is a conversion happening here or there. Regards.
___________________________________________ May god give u good health and knowledge.
Haha this is not it! ;) I think I get it ... (since it's gonna be hard to fix I left the fix (test) to later) When I merge 2 intersection close to each other (for numerical reason), sometimes the resulting point is not an intersection (despite having for segment attached to it) but just a touch... Will have to put that in... :o
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!
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I deal with this a lot in 3ds Max. Perhaps you could take a look how editable splines work, and that may be of help.
At this stage I am not interested in reading other people's code! ^_^ And I need the (working) algorithm in my .NET app.. I would be interested in a .NET C# library manipulating geometry.. But I can't find any.. (the only one I know is some GIS I forgot the name, and they only deal in polygon, not shape and their API is convoluted...)
A new .NET Serializer All in one Menu-Ribbon Bar Taking over the world since 1371!