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v.rast.stats: raise a warning when no categories found in raster map
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* v.rast.stats: raise a warning when no categories found in raster map
* v.rast.stats: refactor to a functional way
* v.rast.stats: stop after creating columns when no categories found in the raster map
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@pesekon2
pesekon2 committed Feb 12, 2021
1 parent 6fd5eb9 commit 36d59b4
Showing 1 changed file with 179 additions and 111 deletions.
290 changes: 179 additions & 111 deletions scripts/v.rast.stats/v.rast.stats.py
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Original file line number Diff line number Diff line change
Expand Up @@ -154,7 +154,72 @@ def main():
# keep boundary settings
grass.run_command('g.region', align=rasters[0])

# check if DBF driver used, in this case cut to 10 chars col names:
try:
fi = grass.vector_db(map=vector)[int(layer)]
except KeyError:
grass.fatal(_('There is no table connected to this map. '
'Run v.db.connect or v.db.addtable first.'))
# we need this for non-DBF driver:
dbfdriver = fi['driver'] == 'dbf'

# Find out which table is linked to the vector map on the given layer
if not fi['table']:
grass.fatal(_('There is no table connected to this map. '
'Run v.db.connect or v.db.addtable first.'))

# prepare base raster for zonal statistics
prepare_base_raster(vector, layer, rastertmp, vtypes, where)

# get number of raster categories to be processed
number = get_nr_of_categories(vector, layer, rasters, rastertmp, percentile,
colprefixes, basecols, dbfdriver, flags['c'])

# calculate statistics:
grass.message(_("Processing input data (%d categories)...") % number)

for i in range(len(rasters)):
raster = rasters[i]

colprefix, variables_dbf, variables, colnames, extstat = set_up_columns(
vector, layer, percentile, colprefixes[i], basecols, dbfdriver,
flags['c']
)

# get rid of any earlier attempts
grass.try_remove(sqltmp)

# do the stats
perform_stats(raster, percentile, fi, dbfdriver, colprefix,
variables_dbf, variables, colnames, extstat)

grass.message(_("Updating the database ..."))
exitcode = 0
try:
grass.run_command('db.execute', input=sqltmp,
database=fi['database'], driver=fi['driver'])
grass.verbose((_("Statistics calculated from raster map <{raster}>"
" and uploaded to attribute table"
" of vector map <{vector}>."
).format(raster=raster, vector=vector)))
except CalledModuleError:
grass.warning(
_("Failed to upload statistics to attribute table of vector map <%s>.") %
vector)
exitcode = 1

sys.exit(exitcode)


def prepare_base_raster(vector, layer, rastertmp, vtypes, where):
"""Prepare base raster for zonal statistics.
:param vector: name of vector map or data source for direct OGR access
:param layer: layer number or name
:param where: WHERE conditions of SQL statement without 'where' keyword
:param rastertmp: name of temporary raster map
:param vtypes: input feature type
"""
try:
nlines = grass.vector_info_topo(vector)['lines']
kwargs = {}
Expand All @@ -164,11 +229,25 @@ def main():
if flags['d'] and nlines > 0:
kwargs['flags'] = 'd'

grass.run_command('v.to.rast', input=vector, layer=layer, output=rastertmp,
use='cat', type=vtypes, quiet=True, **kwargs)
grass.run_command('v.to.rast', input=vector, layer=layer,
output=rastertmp, use='cat', type=vtypes,
quiet=True, **kwargs)
except CalledModuleError:
grass.fatal(_("An error occurred while converting vector to raster"))


def get_nr_of_categories(vector, layer, rasters, rastertmp, percentile,
colprefixes, basecols, dbfdriver, c):
"""Get number of raster categories to be processed.
Perform also checks of raster and vector categories. In the case of no
raster categories, create the desired columns and exit.
:param vector: name of vector map or data source for direct OGR access
:param layer: layer number or name
:param rastertmp: name of temporary raster map
:return: number of raster categories or exit (if no categories found)
"""
# dump cats to file to avoid "too many argument" problem:
p = grass.pipe_command('r.category', map=rastertmp, sep=';', quiet=True)
cats = []
Expand All @@ -180,115 +259,121 @@ def main():

number = len(cats)
if number < 1:
grass.fatal(_("No categories found in raster map"))
# create columns and exit
grass.warning(_("No categories found in raster map"))
for i in range(len(rasters)):
set_up_columns(
vector, layer, percentile, colprefixes[i], basecols, dbfdriver,
flags['c']
)
sys.exit(0)

# Check if all categories got converted
# Report categories from vector map
vect_cats = grass.read_command('v.category', input=vector, option='report',
flags='g').rstrip('\n').split('\n')
flags='g').rstrip('\n').split('\n')

# get number of all categories in selected layer
vect_cats_n = 0 # to be modified below
for vcl in vect_cats:
if vcl.split(' ')[0] == layer and vcl.split(' ')[1] == 'all':
vect_cats_n = int(vcl.split(' ')[2])

if vect_cats_n != number:
grass.warning(_("Not all vector categories converted to raster. \
Converted {0} of {1}.".format(number, vect_cats_n)))

# check if DBF driver used, in this case cut to 10 chars col names:
try:
fi = grass.vector_db(map=vector)[int(layer)]
except KeyError:
grass.fatal(
_('There is no table connected to this map. Run v.db.connect or v.db.addtable first.'))
# we need this for non-DBF driver:
dbfdriver = fi['driver'] == 'dbf'

# Find out which table is linked to the vector map on the given layer
if not fi['table']:
grass.fatal(
_('There is no table connected to this map. Run v.db.connect or v.db.addtable first.'))

# replaced by user choiche
#basecols = ['n', 'min', 'max', 'range', 'mean', 'stddev', 'variance', 'cf_var', 'sum']

for i in range(len(rasters)):
raster = rasters[i]
colprefix = colprefixes[i]
# we need at least three chars to distinguish [mea]n from [med]ian
# so colprefix can't be longer than 6 chars with DBF driver
Converted {0} of {1}.".format(number, vect_cats_n)))

return number


def set_up_columns(vector, layer, percentile, colprefix, basecols, dbfdriver,
c):
"""Get columns-depending variables and create columns, if needed.
:param vector: name of vector map or data source for direct OGR access
:param layer: layer number or name
:param percentile: percentile to calculate
:param colprefix: column prefix for new attribute columns
:param basecols: the methods to use
:param dbfdriver: boolean saying if the driver is dbf
:param c: boolean saying if it should continue if upload column(s) already
exist
:return: colprefix, variables_dbf, variables, colnames, extstat
"""
# we need at least three chars to distinguish [mea]n from [med]ian
# so colprefix can't be longer than 6 chars with DBF driver
variables_dbf = {}

if dbfdriver:
colprefix = colprefix[:6]

# by default perccol variable is used only for "variables" variable
perccol = "percentile"
perc = None
for b in basecols:
if b.startswith('p'):
perc = b
if perc:
# namespace is limited in DBF but the % value is important
if dbfdriver:
colprefix = colprefix[:6]
variables_dbf = {}

# by default perccol variable is used only for "variables" variable
perccol = "percentile"
perc = None
for b in basecols:
if b.startswith('p'):
perc = b
if perc:
# namespace is limited in DBF but the % value is important
if dbfdriver:
perccol = "per" + percentile
else:
perccol = "percentile_" + percentile
percindex = basecols.index(perc)
basecols[percindex] = perccol

# dictionary with name of methods and position in "r.univar -gt" output
variables = {'number': 2, 'null_cells': 3, 'minimum': 4, 'maximum': 5, 'range': 6,
'average': 7, 'stddev': 9, 'variance': 10, 'coeff_var': 11,
'sum': 12, 'first_quartile': 14, 'median': 15,
'third_quartile': 16, perccol: 17}
# this list is used to set the 'e' flag for r.univar
extracols = ['first_quartile', 'median', 'third_quartile', perccol]
addcols = []
colnames = []
extstat = ""
for i in basecols:
# this check the complete name of out input that should be truncated
for k in variables.keys():
if i in k:
i = k
break
if i in extracols:
extstat = 'e'
# check if column already present
currcolumn = ("%s_%s" % (colprefix, i))
if dbfdriver:
currcolumn = currcolumn[:10]
variables_dbf[currcolumn.replace("%s_" % colprefix, '')] = i

colnames.append(currcolumn)
if currcolumn in grass.vector_columns(vector, layer).keys():
if not flags['c']:
grass.fatal((_("Cannot create column <%s> (already present). ") % currcolumn) +
_("Use -c flag to update values in this column."))
perccol = "per" + percentile
else:
perccol = "percentile_" + percentile
percindex = basecols.index(perc)
basecols[percindex] = perccol

# dictionary with name of methods and position in "r.univar -gt" output
variables = {'number': 2, 'null_cells': 3, 'minimum': 4, 'maximum': 5,
'range': 6,
'average': 7, 'stddev': 9, 'variance': 10, 'coeff_var': 11,
'sum': 12, 'first_quartile': 14, 'median': 15,
'third_quartile': 16, perccol: 17}
# this list is used to set the 'e' flag for r.univar
extracols = ['first_quartile', 'median', 'third_quartile', perccol]
addcols = []
colnames = []
extstat = ""
for i in basecols:
# this check the complete name of out input that should be truncated
for k in variables.keys():
if i in k:
i = k
break
if i in extracols:
extstat = 'e'
# check if column already present
currcolumn = ("%s_%s" % (colprefix, i))
if dbfdriver:
currcolumn = currcolumn[:10]
variables_dbf[currcolumn.replace("%s_" % colprefix, '')] = i

colnames.append(currcolumn)
if currcolumn in grass.vector_columns(vector, layer).keys():
if not c:
grass.fatal((_("Cannot create column "
"<%s> (already present). ") % currcolumn) +
_("Use -c flag to update values in this column."))
else:
if i == "n":
coltype = "INTEGER"
else:
if i == "n":
coltype = "INTEGER"
else:
coltype = "DOUBLE PRECISION"
addcols.append(currcolumn + ' ' + coltype)
coltype = "DOUBLE PRECISION"
addcols.append(currcolumn + ' ' + coltype)

if addcols:
grass.verbose(_("Adding columns '%s'") % addcols)
try:
grass.run_command('v.db.addcolumn', map=vector, columns=addcols,
layer=layer)
except CalledModuleError:
grass.fatal(_("Adding columns failed. Exiting."))

# calculate statistics:
grass.message(_("Processing input data (%d categories)...") % number)
if addcols:
grass.verbose(_("Adding columns '%s'") % addcols)
try:
grass.run_command('v.db.addcolumn', map=vector, columns=addcols,
layer=layer)
except CalledModuleError:
grass.fatal(_("Adding columns failed. Exiting."))

# get rid of any earlier attempts
grass.try_remove(sqltmp)
return colprefix, variables_dbf, variables, colnames, extstat

f = open(sqltmp, 'w')

def perform_stats(raster, percentile, fi, dbfdriver, colprefix, variables_dbf,
variables, colnames, extstat):
with open(sqltmp, 'w') as f:
# do the stats
p = grass.pipe_command('r.univar', flags='t' + extstat, map=raster,
zones=rastertmp, percentile=percentile, sep=';')
Expand Down Expand Up @@ -324,24 +409,7 @@ def main():
f.write(" WHERE %s=%s;\n" % (fi['key'], vars[0]))
f.write("{0}\n".format(grass.db_commit_transaction(fi['driver'])))
p.wait()
f.close()

grass.message(_("Updating the database ..."))
exitcode = 0
try:
grass.run_command('db.execute', input=sqltmp,
database=fi['database'], driver=fi['driver'])
grass.verbose((_("Statistics calculated from raster map <{raster}>"
" and uploaded to attribute table"
" of vector map <{vector}>."
).format(raster=raster, vector=vector)))
except CalledModuleError:
grass.warning(
_("Failed to upload statistics to attribute table of vector map <%s>.") %
vector)
exitcode = 1

sys.exit(exitcode)

if __name__ == "__main__":
options, flags = grass.parser()
Expand Down

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