#
# Copyright (C) 2000-2005 by Yasushi Saito (yasushi.saito@gmail.com)
#
# Jockey is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2, or (at your option) any
# later version.
#
# Jockey is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
import coord
import math
class T(coord.T):
def get_canvas_pos(self, size, val, min, max):
if val <= 0:
return 0
xminl = math.log(min)
xmaxl = math.log(max)
vl = math.log(val)
return size * (vl-xminl) / float(xmaxl-xminl)
def get_tics(self, min, max, interval):
"Generate the list of places for drawing tick marks."
v = []
if min <= 0:
raise Exception, "Min value (%s) < 0 in a log coordinate." % min
x = min
while x <= max:
v.append(x)
x = x * interval
return v
def get_min_max(self, dmin, dmax, interval):
interval = interval or 10
dmin = max(0, dmin) # we can't have a negative value with a log scale.
v = 1.0
while v > dmin:
v = v / interval
dmin = v
v = 1.0
while v < dmax:
v = v * interval
dmax = v
return dmin, dmax, interval
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