chessboard | A chessboard module for Python in Linux | Math library

This is kind of a weird issue you ran into! I would love to hear anyone else's answer on this as well, as I am still very curious about the cause of the issue. I did find a solution for you though!

It seems like the knight piece is somehow blocked from being clicked on if it is on a tile that is also a valid move. (If anyone can figure out why please share)

To fix the problem you can add position: absolute to the knight as well as z-index: . This makes the knight div appear above everything else so it is still draggable.

Specifically, you can change your knightStyle in Knight.jsx to this:

I played around a bit and I was able to use this to get it to work. This is around line 90 of your code. It uses your code to check if the move is not the correct one and resets it back until you do the correct move

Calibration using a single view is a poor idea, generally speaking, because of the small number of independent samples it entails, so it is possible that tolerance on the calibration grid manufacture be the least of your worries. But if you must...

The controlling factor here is the sensor's dot pitch. Given the nominal focal length of your lens, and that you want your calibration RMSE to be order of a few tenths of pixel, you can work out the angle spanned by, say, 1/10 of a pixel along the sensor's horizontal axis. Back projecting that at the nominal distance between the lens's exit pupil and the target will give you a length in 3D world that measures the uncertainty in a target's corner location at the calibration optimum. Your physical target points should be known at least as accurately, and normally better.

Example: Setup: Dot pitch 5um, 16mm focal lens, 200mm working distance to target.

• Backprojected 1/10 pixel: 200/16*0.5um =~ 6um.
• Backprojected 1/2 pixel : 200/16*2.5um =~ 31um.

You can loosen that if you assume perfect Chi-square scaling of the errors with the square root of the number of the data points. If you have, say, 100 corners, you can multiply that by 10, i.e. ~ 300um for 1/2 pixel

Note that with this kind of tolerances temperature control (for camera and target) may become a factor to keep into account.

The simplest approach IMO is to have a simple standard square design. Make it so that the thing sits at the origin (0, 0), and then move the whole group to its final position. That way every square is the same apart from class and text content.

The piece position problem is easily solved now. Every element has the same x and y, and you use text-anchor="middle" to centre the piece horizontally. The height works fine because all the pieces are the same height (more or less).

x = e is not the way to update a numpy array, you need to use indexing like you have done here start_pos[sq_rank_num, sq_file_num] = N. But the way you have constructed the for loop (of what you have showed anyway) does not provide any indexes to work with.

For example, if the beginning position of the knight is

If you want the height and width % to work, you should give a height and width to its parent, because thats what they will take as 100%. In this case you had % in main but not stated a width nor height in the body tag.

In this case you can't use those % so I used static px in order to do it faster and to not re-structure the html.

The problem you had with the backgrounds is that when you add an image as a background it overwrites the previous background, so in order to have a transparent image with a styled background you have to add it as content (img) of the container with that background.

I also changed the main class for the main tag and replaced id pawn as you should not have more that one tag with the same id, in other words, it should be unique, if you want to use more, use a class.

This will not work, because of the following issues:

• answer is never populated: it can therefore be nothing else than its initial value, an empty list
• Although you let dp return -1 when a solution is found, this value is never checked by the caller. So the caller does not know about it and goes to the next iteration of its for loop
• When the recursive call of dp returns, the restrictedIndices list is not returned to its previous state. This means that in the next iterations of the for loop the condition [row][i]==1 will always be True -- this cell was set to 1 during the first iteration. You should make sure that each iteration of the for loop starts with the exact same state of restrictedIndices.

I will not post a working solution, as this is extensively documented on the internet, and recursive solutions for Python can be found also on Stack Overflow:

• eight queens problem in Python,
• Backtracking 8 Queens Python problems
• Solving the n-queen puzzle
• 8 Queens Solution in Python
• N Queens: backtracking solution implemented by Python generator

This document.getElementById('board3') is executed before the first render. The node is not available jet. Also every time the component is updated this function will runs. I assume that you don't want that. I recommend you to move your code to useEffect block:

Dealing with widgets that have a fixed aspect ratio is not an easy task, and some precautions must be taken in order to ensure that having an "incompatible" parent size doesn't prevent proper display.

In this case, a possible solution is to use a widget for the chessboard that uses a grid layout for all the squares and pieces.
Note that a QLabel isn't a good choice for the chessboard, as it doesn't allow a size smaller than the QPixmap, so a QWidget should be subclassed instead.

The trick is to override the resizeEvent(), ignore the base implementation (which by default adapts the geometry of the layout) and manually set the geometry based on the minimum extent between width and height.

In order to ensure that the layout has proper equal spacings even when a row or column is empty, setRowStretch() and setColumnStretch() must be called for the whole grid size.

Then, you add the pieces directly to the layout, and whenever you need to move them you can just create a helper function that uses addWidget() with the correct row/column (which will automatically "move" the widget to the new position).

Here is a possible implementation.