# -*- coding: utf-8 -*-
# pylint: disable=C0103
"""
Histogram item
"""
from __future__ import annotations
import weakref
from typing import TYPE_CHECKING
import numpy as np
from guidata.dataset import update_dataset
from guidata.utils.misc import assert_interfaces_valid
from qwt import QwtPlotCurve
from plotpy.config import _
from plotpy.interfaces import IBasePlotItem, IHistDataSource
from plotpy.items.curve.base import CurveItem
from plotpy.styles.curve import CurveParam
from plotpy.styles.histogram import HistogramParam
if TYPE_CHECKING:
from plotpy.items.image.base import BaseImageItem
from plotpy.styles.base import ItemParameters
class HistDataSource:
"""An objects that provides an Histogram data source interface
to a simple numpy array of data
"""
__implements__ = (IHistDataSource,)
def __init__(self, data: np.ndarray) -> None:
self.data = data
def get_histogram(
self, nbins: int, drange: tuple[float, float] | None = None
) -> tuple[np.ndarray, np.ndarray]:
"""
Return a tuple (hist, bins) where hist is a list of histogram values
Args:
nbins: number of bins
drange: lower and upper range of the bins. If not provided, range is
simply (data.min(), data.max()). Values outside the range are ignored.
Returns:
Tuple (hist, bins)
"""
return np.histogram(self.data, bins=nbins, range=drange)
assert_interfaces_valid(HistDataSource)
[docs]
class HistogramItem(CurveItem):
"""Histogram plot item
Args:
curveparam: Curve parameters
histparam: Histogram parameters
"""
__implements__ = (IBasePlotItem,)
_icon_name = "histogram.png"
def __init__(
self,
curveparam: CurveParam | None = None,
histparam: HistogramParam | None = None,
keep_weakref: bool = False,
) -> None:
self.hist_count = None
self.hist_bins = None
self.bins = None
self.bin_range = None
self.old_bins = None
self.source: BaseImageItem | None = None
self.logscale: bool | None = None
self.old_logscale = None
self.keep_weakref = keep_weakref
if curveparam is None:
curveparam = CurveParam(_("Curve"), icon="curve.png")
curveparam.curvestyle = "Steps"
if histparam is None:
self.histparam = HistogramParam(title=_("Histogram"), icon="histogram.png")
else:
self.histparam = histparam
CurveItem.__init__(self, curveparam)
self.setCurveAttribute(QwtPlotCurve.Inverted)
[docs]
def set_hist_source(self, src: BaseImageItem) -> None:
"""Set histogram source
Args:
src: Object with method `get_histogram`, e.g. objects derived from
:py:class:`.ImageItem`
"""
if self.keep_weakref:
self.source = weakref.ref(src)
else:
self.source = src
self.update_histogram()
[docs]
def get_hist_source(self) -> BaseImageItem | None:
"""Return histogram source
Returns:
object: Object with method `get_histogram`, e.g. objects derived from
:py:class:`.ImageItem`
"""
if self.source is not None:
if self.keep_weakref:
return self.source()
return self.source
[docs]
def set_hist_data(self, data: np.ndarray) -> None:
"""Set histogram data
Args:
data: numpy array
"""
self.set_hist_source(HistDataSource(data))
[docs]
def set_logscale(self, state: bool) -> None:
"""Sets whether we use a logarithm or linear scale
for the histogram counts
Args:
state: True for logarithmic scale
"""
self.logscale = state
self.update_histogram()
[docs]
def get_logscale(self) -> bool | None:
"""Returns the status of the scale
Returns:
bool: True for logarithmic scale
"""
return self.logscale
[docs]
def set_bins(self, n_bins: int) -> None:
"""Sets the number of bins
Args:
n_bins: number of bins
"""
self.bins = n_bins
self.update_histogram()
[docs]
def get_bins(self) -> int | None:
"""Returns the number of bins
Returns:
int: number of bins
"""
return self.bins
[docs]
def set_bin_range(self, bin_range: tuple[float, float] | None) -> None:
"""Sets the range of the bins
Args:
bin_range: (min, max) or None for automatic range
"""
self.bin_range = bin_range
self.update_histogram()
[docs]
def get_bin_range(self) -> tuple[float, float] | None:
"""Returns the range of the bins
Returns:
tuple: (min, max)
"""
return self.bin_range
[docs]
def compute_histogram(self) -> tuple[np.ndarray, np.ndarray]:
"""Compute histogram data
Returns:
tuple: (hist, bins)
"""
return self.get_hist_source().get_histogram(self.bins, self.bin_range)
[docs]
def update_histogram(self) -> None:
"""Update histogram data"""
if self.get_hist_source() is None:
return
hist, bin_edges = self.compute_histogram()
# Duplicate the first `hist` value to get a step-like histogram:
hist = np.concatenate(([hist[0]], hist))
if self.logscale:
hist = np.log(hist + 1)
self.set_data(bin_edges, hist)
# Autoscale only if logscale/bins have changed
if self.bins != self.old_bins or self.logscale != self.old_logscale:
if self.plot():
self.plot().do_autoscale()
self.old_bins = self.bins
self.old_logscale = self.logscale
plot = self.plot()
if plot is not None:
plot.do_autoscale(replot=True)
[docs]
def update_params(self):
"""Update histogram parameters"""
self.histparam.update_hist(self)
CurveItem.update_params(self)
[docs]
def get_item_parameters(self, itemparams: ItemParameters) -> None:
"""
Appends datasets to the list of DataSets describing the parameters
used to customize apearance of this item
Args:
itemparams: Item parameters
"""
CurveItem.get_item_parameters(self, itemparams)
itemparams.add("HistogramParam", self, self.histparam)
[docs]
def set_item_parameters(self, itemparams):
"""
:param itemparams:
"""
update_dataset(
self.histparam, itemparams.get("HistogramParam"), visible_only=True
)
self.histparam.update_hist(self)
CurveItem.set_item_parameters(self, itemparams)
assert_interfaces_valid(HistogramItem)
