Extended statistics (-e) adds median, 1st and 3rd quartiles, and 90th percentile to the output.
g.region raster=elevation -p v.random output=samples npoints=100 v.db.addtable map=samples columns="heights double precision" v.what.rast map=samples rast=elevation column=heights v.db.select map=samples
v.univar -e samples column=heights type=point number of features with non NULL attribute: 100 number of missing attributes: 0 number of NULL attributes: 0 minimum: 57.2799 maximum: 148.903 range: 91.6235 sum: 10825.6 mean: 108.256 mean of absolute values: 108.256 population standard deviation: 20.2572 population variance: 410.356 population coefficient of variation: 0.187123 sample standard deviation: 20.3593 sample variance: 414.501 kurtosis: -0.856767 skewness: 0.162093 1st quartile: 90.531 median (even number of cells): 106.518 3rd quartile: 126.274 90th percentile: 135.023
r.univar -e elevation total null and non-null cells: 2025000 total null cells: 0 Of the non-null cells: ---------------------- n: 2025000 minimum: 55.5788 maximum: 156.33 range: 100.751 mean: 110.375 mean of absolute values: 110.375 standard deviation: 20.3153 variance: 412.712 variation coefficient: 18.4057 % sum: 223510266.558102 1st quartile: 94.79 median (even number of cells): 108.88 3rd quartile: 126.792 90th percentile: 138.66
v.univar -d samples type=point number of primitives: 100 number of non zero distances: 4851 number of zero distances: 0 minimum: 69.9038 maximum: 18727.7 range: 18657.8 sum: 3.51907e+07 mean: 7254.33 mean of absolute values: 7254.33 population standard deviation: 3468.53 population variance: 1.20307e+07 population coefficient of variation: 0.478132 sample standard deviation: 3468.89 sample variance: 1.20332e+07 kurtosis: -0.605406 skewness: 0.238688
v.univar -e samples column=heights type=point format=json
{ "n": 1832, "missing": 0, "nnull": 0, "min": 166.946991, "max": 2729482.25, "range": 2729315.3030090001, "sum": 78876146.145385057, "mean": 43054.664926520229, "mean_abs": 43054.664926520229, "population_stddev": 132689.08650029532, "population_variance": 17606393676.282852, "population_coeff_variation": 3.0818747916573215, "sample_stddev": 132725.31560308655, "sample_variance": 17616009401.938931, "kurtosis": 139.15698418811229, "skewness": 9.7065048189730767, "first_quartile": 3699.3234859999998, "median": 10308.4453125, "third_quartile": 29259.074218999998, "percentiles": [ { "percentile": 90, "value": 86449.734375 } ] }
extended by:
Hamish Bowman, University of Otago, New Zealand
Martin Landa