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How can i convert the axis coordinates into pixel coordinates? I have a set of data which include the negative and floating values, i need to put all of the data into the image. But the pixel coordinates are all positive integer. how to solve the negative issue? You can pass vectors of coordinates to scatter . x = [-1.2 -2.4 0.3 7]; y = [2 -1 1 -3]; scatter(x,y,'.'); If you need the image matrix, h = figure(); scatter(x,y); F = getframe(h); img = F.cdata; You can also use print to save the plot to a file (or simply export from figure window), then use imread to read the file. There is also

I'm building a boardgame in WebGL. The board can be rotated/zoomed. I need a way to translate a click on the canvas element (x,y) into the relevant point in 3D space (x, y, z). The ultimate result is that I want to know the (x, y, z) coordinate that contains the point that touches the object closest to the user. For instance, the user clicks a piece, and you imagine a ray traveling through 3D space that goes through both the piece and the game board, but I want the (x, y, z) coord of the piece at the point where it was touched. I feel like this must be a very common problem, but I can't seem