A_Star | A* algorithm example -

I am using the shortest path algorithm from LightGraphs.jl. In the end I want to collect some information about the nodes along the path. In order to do that I need to be able to extract the vertices from the edges that the function gives back.

So I'm new to both pathfinding and and pygame but I'm trying to visualize the matrix into a grid in pygame. However, when I try the boxes get further and further away and it infinitely loops. So my question is how can i Get this to display a 4x4 grind like my matrix, with each square properly spaced? The code was split into 2 files. the main problem is in the second, I put the first here just for context. Also just theory is fine too I don't necessarily need a code solution just wann wrap my head around this.

P.s. To any familiar with pygame is there anyway to get the Grid/grid.node() information from the pathfinder? thatd make this a bit easier i think

EDIT:

For anyone in the future having this problem:

PLEASE check whether or not you have a block of code that creates object instances and remove that first before asking something similar.

** Start of the question:**

I wanted to implement Conway's Game of Life with Tkinter. My code does seem to work, but everytime I start the app, it slows down until the canvas only updates like every second.

I have already looked into similar questions, but the problem here is that in every single one of them, the people continuously created rectangles which obviously causes frame rate problems, but I changed that in my implementation (I initialize the canvas with ROWS*COLS rectangles, then only change their color).

The main function that is responsible for updating the canvas is the "startConway()" - function. As you can see, i tried measuring the time (t0,t1,t2) to see whether or not one for loop is causing problems, but even though the canvas slows down, the times stay nearly constant and always under 20 ms.

Is there something I do not know about Tkinter that hinders my progress? Or is my approach just far to slow? Where can improvements be made?

If you want to try it out, just copy the code, then run it. On the canvas, click some pixels then finally to start the Conway game, click on a black pixel.

Thanks in advance.

Here is the code:

I have a grid in matplotlib (20*20 or 40*40 based on user's choice) that contains data divided based on LatLong location. Each cell in that grid represents a 0.002 or 0.001 area (ex: [-70.55, 43.242] to [-70.548, 43.244]). The grid is coloured basesd on threshold value, say anything above 30 is green and anything below is red.

I implemented the A start algorithm to go from one location (cell) to another on that graph while avoiding all green cells. The cost of traveling on a border of a green and red cell is 1.3 while the diagonal cost is 1.5, and traveling between two red cells is 1.

I'm using the diagonal distance heuristic, and for each cell I'm getting all possible neighbours and setting their G value based on the threshold.

Now I'm able to get a correct path most of the time, and for cells that are nearby, it runs at sub 1 sec. but when I go further it takes 14-18 seconds.

I don't understand what wrong I'm doing here? I've been trying to figure out a way to improve it but failed.

Here's a fragment of the algorithm. I would like to note that determining the accessible neighbours and setting the G value might not be issue here because each function call runs at around 0.02 - 0.03 seconds.

Any advice is appreciated! Thanks

I'm working on creating an AI to play the classic game Snake, and have implemented it somewhat successfully, however every so often the program crashes upon reaching its target. I'm using a modified version of A* for pathfinding and pygame for the graphics.

I'm working on this A_star algorithm in Python and when the algorithm avoids the obstacles, I need to create a safe_zone around the obstacles or the robot itself, until when the robot passes near to the obstacle, there will be no chance to hit the obstacle. So, how could I add this safe_zone? Any assistance, please?

My code is shown below:

I am trying to write an A* pathfinder to learn C++ and am struggling with a specific bug.

These are the features/assumptions of the program:

• The path contains "walls" which cannot be passed
• All paths cost the same value (1)
• Diagonal movement is allowed
• Only one goal

Here is my code:

Currently I have the following project structure, where the libs directory purpose is to store external C libraries that I download from github because they are not available on my OS's repos:

I'm trying to code A* search algorithm but I can't seem to get it to work. I'm copying the pseudocode from wikipedia. My code seems to just search every possible node. Here's my showPath() function: