I have a txt file with massive amounts of points in it(100,000 plus). Obviously the file is too large to be useful in Cad. I am wondering if anyone has any suggestions about a program to thin out these points some. I am wondering if there is software to weed out points within a certain distance of each other or alternatively to just automatically delete each row. the first option would be better.
By the way you talk about rows, do you have some lidar or similar data?
I use Terramodel and whilst I cannot remember the command off the top of my head, I have used one in the past to thin a 1m lidar grid down to a 5m grid so it is a lot more user friendly.
Because we get our Terramodel through a company called Geocomp, we get access to a huge amount of useful commands. See http://www.geocomp.com.au/support/terramodel/tmllist.htm#LIDARGRD for an example that seems like what you want.
Would you mind emailing me the file?
Most likely you could data filter in excel to limit points to be within a certain range of coordinates with out too much trouble.
I might consider using Isenburg's LAStools to accomplish this.. not specifically made for it but will accomplish it for free.
http://www.cs.unc.edu/~isenburg/lastools/
Convert the TXT file to LAS format using his TXT2LAS.exe and then use LASTHIN.exe to do a simple point thinning. He has many programs that will then work with this data, allowing you to create contours, google earth, many handy tools there and all free to download.
