import sys
import time
from collections import OrderedDict
from datetime import datetime, timedelta, timezone
import numpy as np
from .AxisItem import AxisItem
__all__ = ['DateAxisItem']
MS_SPACING = 1/1000.0
SECOND_SPACING = 1
MINUTE_SPACING = 60
HOUR_SPACING = 3600
DAY_SPACING = 24 * HOUR_SPACING
WEEK_SPACING = 7 * DAY_SPACING
MONTH_SPACING = 30 * DAY_SPACING
YEAR_SPACING = 365 * DAY_SPACING
if sys.platform == 'win32':
_epoch = datetime.fromtimestamp(0, timezone.utc)
def utcfromtimestamp(timestamp):
return _epoch + timedelta(seconds=timestamp)
else:
def utcfromtimestamp(timestamp):
return datetime.fromtimestamp(timestamp, timezone.utc)
MIN_REGULAR_TIMESTAMP = (datetime(1, 1, 1) - datetime(1970,1,1)).total_seconds()
MAX_REGULAR_TIMESTAMP = (datetime(9999, 1, 1) - datetime(1970,1,1)).total_seconds()
SEC_PER_YEAR = 365.25*24*3600
# The stepper functions provide
# 'first' == True: The first tick value for 'val' being the minimum of the current view.
# 'first' == False: The next tick value for 'val' being the previous tick value.
def makeMSStepper(stepSize):
def stepper(val, n, first: bool):
if val < MIN_REGULAR_TIMESTAMP or val > MAX_REGULAR_TIMESTAMP:
return np.inf
if first:
val *= 1000
f = stepSize * 1000
return (val // (n * f) + 1) * (n * f) / 1000.0
else:
return val + n * stepSize
return stepper
def makeSStepper(stepSize):
def stepper(val, n, first: bool):
if val < MIN_REGULAR_TIMESTAMP or val > MAX_REGULAR_TIMESTAMP:
return np.inf
if first:
return (val // (n * stepSize) + 1) * (n * stepSize)
else:
return val + n * stepSize
return stepper
def makeMStepper(stepSize):
def stepper(val, n, first: bool):
if val < MIN_REGULAR_TIMESTAMP or val > MAX_REGULAR_TIMESTAMP:
return np.inf
d = utcfromtimestamp(val)
base0m = d.month + n * stepSize - 1
d = datetime(d.year + base0m // 12, base0m % 12 + 1, 1)
return (d - datetime(1970, 1, 1)).total_seconds()
return stepper
def makeYStepper(stepSize):
def stepper(val, n, first: bool):
if val < MIN_REGULAR_TIMESTAMP or val > MAX_REGULAR_TIMESTAMP:
return np.inf
d = utcfromtimestamp(val)
next_year = (d.year // (n * stepSize) + 1) * (n * stepSize)
if next_year > 9999:
return np.inf
next_date = datetime(next_year, 1, 1)
return (next_date - datetime(1970, 1, 1)).total_seconds()
return stepper
class TickSpec:
""" Specifies the properties for a set of date ticks and computes ticks
within a given utc timestamp range """
def __init__(self, spacing, stepper, format, autoSkip=None):
"""
============= ==========================================================
Arguments
spacing approximate (average) tick spacing
stepper a stepper function that takes a utc time stamp and a step
steps number n to compute the start of the next unit. You
can use the make_X_stepper functions to create common
steppers.
format a strftime compatible format string which will be used to
convert tick locations to date/time strings
autoSkip list of step size multipliers to be applied when the tick
density becomes too high. The tick spec automatically
applies additional powers of 10 (10, 100, ...) to the list
if necessary. Set to None to switch autoSkip off
============= ==========================================================
"""
self.spacing = spacing
self.step = stepper
self.format = format
self.autoSkip = autoSkip
def makeTicks(self, minVal, maxVal, minSpc):
ticks = []
n = self.skipFactor(minSpc)
x = self.step(minVal, n, first=True)
while x <= maxVal:
ticks.append(x)
x = self.step(x, n, first=False)
return (np.array(ticks), n)
def skipFactor(self, minSpc):
if self.autoSkip is None or minSpc < self.spacing:
return 1
factors = np.array(self.autoSkip, dtype=np.float64)
while True:
for f in factors:
spc = self.spacing * f
if spc > minSpc:
return int(f)
factors *= 10
class ZoomLevel:
""" Generates the ticks which appear in a specific zoom level """
def __init__(self, tickSpecs, exampleText):
"""
============= ==========================================================
tickSpecs a list of one or more TickSpec objects with decreasing
coarseness
============= ==========================================================
"""
self.tickSpecs = tickSpecs
self.utcOffset = 0
self.exampleText = exampleText
def tickValues(self, minVal, maxVal, minSpc):
# return tick values for this format in the range minVal, maxVal
# the return value is a list of tuples (<avg spacing>, [tick positions])
# minSpc indicates the minimum spacing (in seconds) between two ticks
# to fullfill the maxTicksPerPt constraint of the DateAxisItem at the
# current zoom level. This is used for auto skipping ticks.
allTicks = np.array([])
valueSpecs = []
# back-project (minVal maxVal) to UTC, compute ticks then offset to
# back to local time again
utcMin = minVal - self.utcOffset
utcMax = maxVal - self.utcOffset
for spec in self.tickSpecs:
ticks, skipFactor = spec.makeTicks(utcMin, utcMax, minSpc)
# reposition tick labels to local time coordinates
ticks += self.utcOffset
# remove any ticks that were present in higher levels
# we assume here that if the difference between a tick value and a previously seen tick value
# is less than min-spacing/100, then they are 'equal' and we can ignore the new tick.
close = np.any(
np.isclose(allTicks, ticks[:, np.newaxis], rtol=0, atol=minSpc * 0.01),
axis=-1,
)
ticks = ticks[~close]
allTicks = np.concatenate([allTicks, ticks])
valueSpecs.append((spec.spacing, ticks.tolist()))
# if we're skipping ticks on the current level there's no point in
# producing lower level ticks
if skipFactor > 1:
break
return valueSpecs
YEAR_MONTH_ZOOM_LEVEL = ZoomLevel([
TickSpec(YEAR_SPACING, makeYStepper(1), '%Y', autoSkip=[1, 5, 10, 25]),
TickSpec(MONTH_SPACING, makeMStepper(1), '%b')
], "YYYY")
MONTH_DAY_ZOOM_LEVEL = ZoomLevel([
TickSpec(MONTH_SPACING, makeMStepper(1), '%b'),
TickSpec(DAY_SPACING, makeSStepper(DAY_SPACING), '%d', autoSkip=[1, 5])
], "MMM")
DAY_HOUR_ZOOM_LEVEL = ZoomLevel([
TickSpec(DAY_SPACING, makeSStepper(DAY_SPACING), '%a %d'),
TickSpec(HOUR_SPACING, makeSStepper(HOUR_SPACING), '%H:%M', autoSkip=[1, 6])
], "MMM 00")
HOUR_MINUTE_ZOOM_LEVEL = ZoomLevel([
TickSpec(DAY_SPACING, makeSStepper(DAY_SPACING), '%a %d'),
TickSpec(MINUTE_SPACING, makeSStepper(MINUTE_SPACING), '%H:%M',
autoSkip=[1, 5, 15])
], "MMM 00")
HMS_ZOOM_LEVEL = ZoomLevel([
TickSpec(SECOND_SPACING, makeSStepper(SECOND_SPACING), '%H:%M:%S',
autoSkip=[1, 5, 15, 30])
], "99:99:99")
MS_ZOOM_LEVEL = ZoomLevel([
TickSpec(MINUTE_SPACING, makeSStepper(MINUTE_SPACING), '%H:%M:%S'),
TickSpec(MS_SPACING, makeMSStepper(MS_SPACING), '%S.%f',
autoSkip=[1, 5, 10, 25])
], "99:99:99")
def getOffsetFromUtc():
"""Retrieve the utc offset respecting the daylight saving time"""
ts = time.localtime()
if ts.tm_isdst:
utc_offset = time.altzone
else:
utc_offset = time.timezone
return utc_offset
[docs]
class DateAxisItem(AxisItem):
"""
**Bases:** :class:`AxisItem <pyqtgraph.AxisItem>`
An AxisItem that displays dates from unix timestamps.
The display format is adjusted automatically depending on the current time
density (seconds/point) on the axis. For more details on changing this
behaviour, see :func:`setZoomLevelForDensity() <pyqtgraph.DateAxisItem.setZoomLevelForDensity>`.
Can be added to an existing plot e.g. via
:func:`setAxisItems({'bottom':axis}) <pyqtgraph.PlotItem.setAxisItems>`.
"""
[docs]
def __init__(self, orientation='bottom', utcOffset=None, **kwargs):
"""
Create a new DateAxisItem.
For `orientation` and `**kwargs`, see
:func:`AxisItem.__init__ <pyqtgraph.AxisItem.__init__>`.
"""
super(DateAxisItem, self).__init__(orientation, **kwargs)
# Set the zoom level to use depending on the time density on the axis
if utcOffset is None:
utcOffset = getOffsetFromUtc()
self.utcOffset = utcOffset
self.zoomLevels = OrderedDict([
(np.inf, YEAR_MONTH_ZOOM_LEVEL),
(5 * 3600*24, MONTH_DAY_ZOOM_LEVEL),
(6 * 3600, DAY_HOUR_ZOOM_LEVEL),
(15 * 60, HOUR_MINUTE_ZOOM_LEVEL),
(30, HMS_ZOOM_LEVEL),
(1, MS_ZOOM_LEVEL),
])
self.autoSIPrefix = False
def tickStrings(self, values, scale, spacing):
tickSpecs = self.zoomLevel.tickSpecs
tickSpec = next((s for s in tickSpecs if s.spacing == spacing), None)
try:
dates = [utcfromtimestamp(v - self.utcOffset) for v in values]
except (OverflowError, ValueError, OSError):
# should not normally happen
return ['%g' % ((v-self.utcOffset)//SEC_PER_YEAR + 1970) for v in values]
formatStrings = []
for x in dates:
try:
s = x.strftime(tickSpec.format)
if '%f' in tickSpec.format:
# we only support ms precision
s = s[:-3]
elif '%Y' in tickSpec.format:
s = s.lstrip('0')
formatStrings.append(s)
except ValueError: # Windows can't handle dates before 1970
formatStrings.append('')
return formatStrings
def tickValues(self, minVal, maxVal, size):
density = (maxVal - minVal) / size
self.setZoomLevelForDensity(density)
values = self.zoomLevel.tickValues(minVal, maxVal, minSpc=self.minSpacing)
return values
[docs]
def setZoomLevelForDensity(self, density):
"""
Setting `zoomLevel` and `minSpacing` based on given density of seconds per pixel
The display format is adjusted automatically depending on the current time
density (seconds/point) on the axis. You can customize the behaviour by
overriding this function or setting a different set of zoom levels
than the default one. The `zoomLevels` variable is a dictionary with the
maximal distance of ticks in seconds which are allowed for each zoom level
before the axis switches to the next coarser level. To customize the zoom level
selection, override this function.
"""
padding = 10
# Size in pixels a specific tick label will take
if self.orientation in ['bottom', 'top']:
def sizeOf(text):
return self.fontMetrics.boundingRect(text).width() + padding
else:
def sizeOf(text):
return self.fontMetrics.boundingRect(text).height() + padding
# Fallback zoom level: Years/Months
self.zoomLevel = YEAR_MONTH_ZOOM_LEVEL
for maximalSpacing, zoomLevel in self.zoomLevels.items():
size = sizeOf(zoomLevel.exampleText)
# Test if zoom level is too fine grained
if maximalSpacing/size < density:
break
self.zoomLevel = zoomLevel
# Set up zoomLevel
self.zoomLevel.utcOffset = self.utcOffset
# Calculate minimal spacing of items on the axis
size = sizeOf(self.zoomLevel.exampleText)
self.minSpacing = density*size
[docs]
def linkToView(self, view):
"""Link this axis to a ViewBox, causing its displayed range to match the visible range of the view."""
self._linkToView_internal(view) # calls original linkToView code
# Set default limits
_min = MIN_REGULAR_TIMESTAMP
_max = MAX_REGULAR_TIMESTAMP
if self.orientation in ['right', 'left']:
view.setLimits(yMin=_min, yMax=_max)
else:
view.setLimits(xMin=_min, xMax=_max)
def generateDrawSpecs(self, p):
# Get font metrics from QPainter
# Not happening in "paint", as the QPainter p there is a different one from the one here,
# so changing that font could cause unwanted side effects
if self.style['tickFont'] is not None:
p.setFont(self.style['tickFont'])
self.fontMetrics = p.fontMetrics()
# Get font scale factor by current window resolution
return super(DateAxisItem, self).generateDrawSpecs(p)
