Source code for NanoVNASaver.Charts.Magnitude

#  NanoVNASaver
#
#  A python program to view and export Touchstone data from a NanoVNA
#  Copyright (C) 2019, 2020  Rune B. Broberg
#  Copyright (C) 2020,2021 NanoVNA-Saver Authors
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
import math
import logging

from PyQt6 import QtGui

from NanoVNASaver.RFTools import Datapoint
from NanoVNASaver.Charts.Chart import Chart
from NanoVNASaver.Charts.Frequency import FrequencyChart

logger = logging.getLogger(__name__)


[docs]class MagnitudeChart(FrequencyChart): def __init__(self, name=""): super().__init__(name) self.minDisplayValue = 0 self.fixedValues = True self.y_action_fixed_span.setChecked(True) self.y_action_automatic.setChecked(False) self.minValue = 0
[docs] def drawValues(self, qp: QtGui.QPainter): if not self.data and not self.reference: return self._set_start_stop() # Draw bands if required if self.bands.enabled: self.drawBands(qp, self.fstart, self.fstop) if self.fixedValues: max_value = self.maxDisplayValue min_value = self.minDisplayValue else: # Find scaling min_value = 100 max_value = 0 for d in self.data: mag = self.magnitude(d) max_value = max(max_value, mag) min_value = min(min_value, mag) # Also check min/max for the reference sweep for d in self.reference: if d.freq < self.fstart or d.freq > self.fstop: continue max_value = max(max_value, mag) min_value = min(min_value, mag) min_value = 10 * math.floor(min_value / 10) max_value = 10 * math.ceil(max_value / 10) self.maxValue = max_value self.minValue = min_value self.span = (max_value - min_value) or 0.01 target_ticks = int(self.dim.height // 60) for i in range(target_ticks): val = min_value + i / target_ticks * self.span y = self.topMargin + int( (self.maxValue - val) / self.span * self.dim.height ) qp.setPen(Chart.color.text) if val != min_value: digits = max(0, min(2, math.floor(3 - math.log10(abs(val))))) vswrstr = ( str(round(val)) if digits == 0 else str(round(val, digits)) ) qp.drawText(3, y + 3, vswrstr) qp.setPen(QtGui.QPen(Chart.color.foreground)) qp.drawLine( self.leftMargin - 5, y, self.leftMargin + self.dim.width, y ) qp.setPen(QtGui.QPen(Chart.color.foreground)) qp.drawLine( self.leftMargin - 5, self.topMargin, self.leftMargin + self.dim.width, self.topMargin, ) qp.setPen(Chart.color.text) qp.drawText(3, self.topMargin + 4, str(max_value)) qp.drawText(3, self.dim.height + self.topMargin, str(min_value)) self.drawFrequencyTicks(qp) qp.setPen(Chart.color.swr) for vswr in self.swrMarkers: if vswr <= 1: continue mag = (vswr - 1) / (vswr + 1) y = self.topMargin + int( (self.maxValue - mag) / self.span * self.dim.height ) qp.drawLine(self.leftMargin, y, self.leftMargin + self.dim.width, y) qp.drawText(self.leftMargin + 3, y - 1, f"VSWR: {vswr}") self.drawData(qp, self.data, Chart.color.sweep) self.drawData(qp, self.reference, Chart.color.reference) self.drawMarkers(qp)
[docs] def getYPosition(self, d: Datapoint) -> int: mag = self.magnitude(d) return self.topMargin + int( (self.maxValue - mag) / self.span * self.dim.height )
[docs] def valueAtPosition(self, y) -> list[float]: absy = y - self.topMargin val = -1 * ((absy / self.dim.height * self.span) - self.maxValue) return [val]
[docs] @staticmethod def magnitude(p: Datapoint) -> float: return math.sqrt(p.re**2 + p.im**2)
[docs] def copy(self): new_chart = super().copy() new_chart.span = self.span return new_chart