Procedure: thm_part_slice_extract Purpose: Returns a 2-D slice of a scattered 3-D distribution along the designated plane. Points near the slice plane are projected onto the plane and then interpolated onto a regular grid using the nearest neighbor method. Arguments: DATA: An array of N datapoints to be used. VECTORS: An array of N x 3 datapoints designating, respectively, the x,y,z values for each point in DATA RESOLUTION: The number of points along each dimention of the interpolated slice Input Keywords: CENTER: A vector designating the slice plane's center, default = [0,0,0] NORMAL: A vector designating the slice plane's normal, default = [0,0,1] XVEC: A vector whose projection into the slice plane will form its x-axis. The data's x-axis is used by default, if no projection exists an error will be returned SLICE_WIDTH: The width of the slice given in % (of data range) Output Keywords: XGRID: Array of x-locations for the slice. YGRID: Array of y-locations for the slice. FAIL: This keyword will contain a message in the event of an error