Hi,
I wasn't quite sure how to phrase the question so I'll give a little bit of back ground. I'm mapping the X, Y, Z coordinates of returns from a LIDAR sensor onto a 2D Occupancy Grid (I can do that successfully). The array of all LIDAR returns is 3 x L (where L is the number of returns in a LIDAR rotation, typically around 18,000). So far I've been mapping the returns by changing the cell value at each X, Y point by using these as the indices and essentially ignoring Z.
What I would like to do, is find the maximum difference in Z for all returns within a given cell. For example, each occupancy cell in my grid (a 200x200 cell grid) represents a 0.25mx0.25m area, so any XY pair that falls within 0-0.25 are all mapped to the same cell. Not a problem, as it just enqueues the same value change.
What I would like to do is change the value of each cell to the maximum difference in Z for all returns within that cell, i..e |Zmax-Zmin|. This is for filtering purposes later, I have attempted this in two VIs, the first of which is the simple process I have implemented for finding this value from a simple array. The second VI is my attempt to implement this method to set the value of each cell in a large array. In this version, I incrememnt the range of X and Y I am searching for by "Cell Size" using the iterations of a nested loop to scan through each element in the array. It does seem to work but scanning through every element just seems inordinately slow and speed is a definite factor for how I intend to implement this.
How can I improve either of these VIs to better achieve my goal?
I apologise for the long-winded question, but I thought some context might help convery my question.
Any and all advice is appreciated.
