[postgis-users] build_histogram2d function problem

[caij at lreis.ac.cn]

Hi all,
    I want to know how to use the function build_histogram2d(histogram2d, text, text) to build the histogram2d of gist index.
    I have tried use it like this:
    select build_histogram2d('HISTOGRAM2D(xmin ymin,xmax ymin)','quanbj1_10000_6_9_fullscreen', 'wkb_geometry')
    when i run it ,i get the error information like this:"ERROR:  lwhistogram2d parser - doesnt have a ; in sring!"
    anybody who can tell me the reason?and anybody can tell me how to build the histogram2d of gist index.
    
    u r appreciated!