[reportlab-users] Need to extend NormalDateXValueAxis to be with hour, minute and second

[Robin Becker]

On 09/05/2016 12:30, Fatih Karatana wrote:
> Hi,
>
> In the current version, we have only date value on
> NormalDateXValueAxis like "yyyy-mm-dd", but what I need to extend this display
> by including hour, minutes and seconds too.
>
> It will certainly help on my project to arrange the LinePlot graph
> values by hourly period.
>
> Any help and advice will be appreciated.
>

I eventually came up with this which seems to do something sensible although you 
may want to change the ticking strategy.



class TimeValueAxis:
	_mc = 60
	_hc = 60*_mc
	_dc = 24*_hc

	def __init__(self,*args,**kwds):
		if not self.labelTextFormat:
			self.labelTextFormat = self.timeLabelTextFormatter
		self._saved_tickInfo = {}

	def _calcValueStep(self):
		'''Calculate _valueStep for the axis or get from valueStep.'''
		if self.valueStep is None:
			rawRange = self._valueMax - self._valueMin
			rawInterval = rawRange / 
min(float(self.maximumTicks-1),(float(self._length)/self.minimumTickSpacing))
			#here's where we try to choose the correct value for the unit
			if rawInterval >= self._dc:
				d = self._dc
				self._unit = 'days'
			elif rawInterval >= self._hc:
				d = self._hc
				self._unit = 'hours'
			elif rawInterval >= self._mc:
				d = self._mc
				self._unit = 'minutes'
			else:
				d = 1
				self._unit = 'seconds'
			self._unitd = d
			if d>1:
				rawInterval = int(rawInterval/d)
			self._valueStep = nextRoundNumber(rawInterval) * d
		else:
			self._valueStep = self.valueStep

	def timeLabelTextFormatter(self,val):
		u = self._unitd
		k = (u,tuple(self._tickValues))
		if k in self._saved_tickInfo:
			fmt = self._saved_tickInfo[k]
		else:
			uf = float(u)
			tv = [v/uf for v in self._tickValues]
			s = self._unit[0]
			if _allInt(tv):
				fmt = lambda x, uf=uf, s=s: '%.0f%s' % (x/uf,s)
			else:
				stv = ['%.10f' % v for v in tv]
				stvl = max((len(v.rstrip('0'))-v.index('.')) for v in stv)
				if u==1:
					fmt = lambda x,uf=uf,fmt='%%.%dfs' % stvl: fmt % (x/uf)
				else:
					#see if we can represent fractions
					fm = 24 if u==self._dc else 60
					fv = [(v - int(v))*fm for v in tv]
					if _allInt(fv):
						s1 = 'h' if u==self._dc else ('m' if u==self._mc else 's')
						fmt = lambda x,uf=uf,fm=fm, fmt='%%d%s%%d%%s' % (s,s1): fmt % 
(int(x/uf),int((x/uf - int(x/uf))*fm))
					else:
						fmt = lambda x,uf=uf,fmt='%%.%df%s' % (stvl,s): fmt % (x/uf)
			self._saved_tickInfo[k] = fmt

		return fmt(val)
		


class XTimeValueAxis(_XTicks,TimeValueAxis,XValueAxis):
	def __init__(self,*args,**kwds):
		XValueAxis.__init__(self,*args,**kwds)
		TimeValueAxis.__init__(self,*args,**kwds)

-- 
Robin Becker