def update_colorbar_scale(figure, image, scale, vmin, vmax):
""""
Updates the colorbar to the scale and limits given.
:param figure: A matplotlib figure instance
:param image: The matplotlib image containing the colorbar
:param scale: The norm scale of the colorbar, this should be a matplotlib colormap norm type
:param vmin: the minimum value on the colorbar
:param vmax: the maximum value on the colorbar
"""
if vmin <= 0 and scale == LogNorm:
vmin = 0.0001 # Avoid 0 log scale error
mantid.kernel.logger.warning(
"Scale is set to logarithmic so non-positive min value has been changed to 0.0001."
)
if vmax <= 0 and scale == LogNorm:
vmax = 1 # Avoid 0 log scale error
mantid.kernel.logger.warning(
"Scale is set to logarithmic so non-positive max value has been changed to 1."
)
image.set_norm(scale(vmin=vmin, vmax=vmax))
if image.colorbar:
image.colorbar.remove()
locator = None
if scale == LogNorm:
locator = LogLocator(subs=np.arange(1, 10))
if locator.tick_values(vmin=vmin, vmax=vmax).size == 0:
locator = LogLocator()
mantid.kernel.logger.warning(
"Minor ticks on colorbar scale cannot be shown "
"as the range between min value and max value is too large"
)
figure.colorbar(image, ticks=locator)
def get_ticks_log(vmin, vmax, numticks=None, extend='outer'):
""" extend: how the min/max poses defined.
'outer': will try to extend it outwards (make min<vmin, max>vmax);
'inner': will try to shrink it inwards;
"""
from math import log10, ceil, floor
from matplotlib.ticker import LogLocator
if vmax > 0:
vmin = max(vmin, min(10**int(log10(vmax/10)-1), 1e-3))
else:
vmax = 1.0
vmin = 0.1
if not numticks:
numticks = 5
if extend == 'outer':
lvmin, lvmax = ceil(log10(vmin)), floor(log10(vmax))
elif extend == 'inner':
lvmin, lvmax = floor(log10(vmin)), ceil(log10(vmax))
n = lvmax - lvmin
stepm = max(1, floor(n/numticks))
if n - stepm * numticks < (stepm+1)*numticks - n:
step = stepm
else:
step = stepm+1
ticks = 10.0**np.arange(lvmin, lvmax, step)
return ticks
# The default scaling algorithm of MPL, not used
subs = np.arange(int(10/numticks), 10, int(10/numticks), dtype=int) if numticks else (1.0,)
locator = LogLocator(subs=subs)
return [t for t in locator.tick_values(vmin, vmax) if t > vmin/10 and t < vmax*10]
