Commit 5ef8b1d0 authored by Luke Campagnola's avatar Luke Campagnola
Browse files

Merge branch 'axis_fix' into develop

    Fixed improper tick spacing and axis scaling
    This requires an API change:
     - AxisItem.setScale(float) has the usual behavior
     - AxisItem.setScale(None) is deprecated (but still works). Instead use:
     - AxisItem.enableAutoSIPrefix(bool) to enable/disable SI prefix scaling
    Also makes the API more intuitive since these features are now accessed and implemented independently.

fixes #4
parents ea6f4ef4 bb2ecd03
......@@ -69,7 +69,8 @@ class AxisItem(GraphicsWidget):
self.tickLength = maxTickLength
self._tickLevels = None ## used to override the automatic ticking system with explicit ticks
self.scale = 1.0
self.autoScale = True
self.autoSIPrefix = True
self.autoSIPrefixScale = 1.0
self.setRange(0, 1)
......@@ -149,8 +150,8 @@ class AxisItem(GraphicsWidget):
self.setWidth()
else:
self.setHeight()
if self.autoScale:
self.setScale()
if self.autoSIPrefix:
self.updateAutoSIPrefix()
def setLabel(self, text=None, units=None, unitPrefix=None, **args):
"""Set the text displayed adjacent to the axis.
......@@ -195,10 +196,10 @@ class AxisItem(GraphicsWidget):
def labelString(self):
if self.labelUnits == '':
if self.scale == 1.0:
if not self.autoSIPrefix or self.autoSIPrefixScale == 1.0:
units = ''
else:
units = asUnicode('(x%g)') % (1.0/self.scale)
units = asUnicode('(x%g)') % (1.0/self.autoSIPrefixScale)
else:
#print repr(self.labelUnitPrefix), repr(self.labelUnits)
units = asUnicode('(%s%s)') % (self.labelUnitPrefix, self.labelUnits)
......@@ -286,31 +287,16 @@ class AxisItem(GraphicsWidget):
def setScale(self, scale=None):
"""
Set the value scaling for this axis. Values on the axis are multiplied
by this scale factor before being displayed as text. By default (scale=None),
this scaling value is automatically determined based on the visible range
and the axis units are updated to reflect the chosen scale factor.
Set the value scaling for this axis.
For example: If the axis spans values from -0.1 to 0.1 and has units set
to 'V' then a scale of 1000 would cause the axis to display values -100 to 100
and the units would appear as 'mV'
Setting this value causes the axis to draw ticks and tick labels as if
the view coordinate system were scaled. By default, the axis scaling is
1.0.
"""
if scale is None:
#if self.drawLabel: ## If there is a label, then we are free to rescale the values
if self.label.isVisible():
#d = self.range[1] - self.range[0]
#(scale, prefix) = fn.siScale(d / 2.)
(scale, prefix) = fn.siScale(max(abs(self.range[0]), abs(self.range[1])))
if self.labelUnits == '' and prefix in ['k', 'm']: ## If we are not showing units, wait until 1e6 before scaling.
scale = 1.0
prefix = ''
self.setLabel(unitPrefix=prefix)
else:
scale = 1.0
self.autoScale = True
else:
self.setLabel(unitPrefix='')
self.autoScale = False
# Deprecated usage, kept for backward compatibility
if scale is None:
scale = 1.0
self.enableAutoSIPrefix(True)
if scale != self.scale:
self.scale = scale
......@@ -318,14 +304,47 @@ class AxisItem(GraphicsWidget):
self.picture = None
self.update()
def enableAutoSIPrefix(self, enable=True):
"""
Enable (or disable) automatic SI prefix scaling on this axis.
When enabled, this feature automatically determines the best SI prefix
to prepend to the label units, while ensuring that axis values are scaled
accordingly.
For example, if the axis spans values from -0.1 to 0.1 and has units set
to 'V' then the axis would display values -100 to 100
and the units would appear as 'mV'
This feature is enabled by default, and is only available when a suffix
(unit string) is provided to display on the label.
"""
self.autoSIPrefix = enable
self.updateAutoSIPrefix()
def updateAutoSIPrefix(self):
if self.label.isVisible():
(scale, prefix) = fn.siScale(max(abs(self.range[0]*self.scale), abs(self.range[1]*self.scale)))
if self.labelUnits == '' and prefix in ['k', 'm']: ## If we are not showing units, wait until 1e6 before scaling.
scale = 1.0
prefix = ''
self.setLabel(unitPrefix=prefix)
else:
scale = 1.0
self.autoSIPrefixScale = scale
self.picture = None
self.update()
def setRange(self, mn, mx):
"""Set the range of values displayed by the axis.
Usually this is handled automatically by linking the axis to a ViewBox with :func:`linkToView <pyqtgraph.AxisItem.linkToView>`"""
if any(np.isinf((mn, mx))) or any(np.isnan((mn, mx))):
raise Exception("Not setting range to [%s, %s]" % (str(mn), str(mx)))
self.range = [mn, mx]
if self.autoScale:
self.setScale()
if self.autoSIPrefix:
self.updateAutoSIPrefix()
self.picture = None
self.update()
......@@ -756,7 +775,7 @@ class AxisItem(GraphicsWidget):
## Get the list of strings to display for this level
if tickStrings is None:
spacing, values = tickLevels[i]
strings = self.tickStrings(values, self.scale, spacing)
strings = self.tickStrings(values, self.autoSIPrefixScale * self.scale, spacing)
else:
strings = tickStrings[i]
......
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