# NanoVNASaver
#
# A python program to view and export Touchstone data from a NanoVNA
# Copyright (C) 2019, 2020 Rune B. Broberg
# Copyright (C) 2020 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 typing import List
from PyQt5 import QtWidgets, QtGui
from NanoVNASaver.RFTools import Datapoint
from .Frequency import FrequencyChart
logger = logging.getLogger(__name__)
class VSWRChart(FrequencyChart):
logarithmicY = False
maxVSWR = 3
span = 2
def __init__(self, name=""):
super().__init__(name)
self.leftMargin = 30
self.chartWidth = 250
self.chartHeight = 250
self.fstart = 0
self.fstop = 0
self.maxDisplayValue = 25
self.minDisplayValue = 1
self.setMinimumSize(self.chartWidth + self.rightMargin + self.leftMargin,
self.chartHeight + self.topMargin + self.bottomMargin)
self.setSizePolicy(QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding,
QtWidgets.QSizePolicy.MinimumExpanding))
pal = QtGui.QPalette()
pal.setColor(QtGui.QPalette.Background, self.backgroundColor)
self.setPalette(pal)
self.setAutoFillBackground(True)
self.y_menu.addSeparator()
self.y_log_lin_group = QtWidgets.QActionGroup(self.y_menu)
self.y_action_linear = QtWidgets.QAction("Linear")
self.y_action_linear.setCheckable(True)
self.y_action_linear.setChecked(True)
self.y_action_logarithmic = QtWidgets.QAction("Logarithmic")
self.y_action_logarithmic.setCheckable(True)
self.y_action_linear.triggered.connect(lambda: self.setLogarithmicY(False))
self.y_action_logarithmic.triggered.connect(lambda: self.setLogarithmicY(True))
self.y_log_lin_group.addAction(self.y_action_linear)
self.y_log_lin_group.addAction(self.y_action_logarithmic)
self.y_menu.addAction(self.y_action_linear)
self.y_menu.addAction(self.y_action_logarithmic)
def setLogarithmicY(self, logarithmic: bool):
self.logarithmicY = logarithmic
self.update()
def copy(self):
new_chart: VSWRChart = super().copy()
new_chart.logarithmicY = self.logarithmicY
return new_chart
def drawValues(self, qp: QtGui.QPainter):
if len(self.data) == 0 and len(self.reference) == 0:
return
pen = QtGui.QPen(self.sweepColor)
pen.setWidth(self.pointSize)
line_pen = QtGui.QPen(self.sweepColor)
line_pen.setWidth(self.lineThickness)
highlighter = QtGui.QPen(QtGui.QColor(20, 0, 255))
highlighter.setWidth(1)
if self.fixedSpan:
fstart = self.minFrequency
fstop = self.maxFrequency
elif len(self.data) > 0:
fstart = self.data[0].freq
fstop = self.data[len(self.data)-1].freq
else:
fstart = self.reference[0].freq
fstop = self.reference[len(self.reference) - 1].freq
self.fstart = fstart
self.fstop = fstop
# Draw bands if required
if self.bands.enabled:
self.drawBands(qp, fstart, fstop)
# Find scaling
if self.fixedValues:
minVSWR = max(1, self.minDisplayValue)
maxVSWR = self.maxDisplayValue
else:
minVSWR = 1
maxVSWR = 3
for d in self.data:
vswr = d.vswr
if vswr > maxVSWR:
maxVSWR = vswr
maxVSWR = min(self.maxDisplayValue, math.ceil(maxVSWR))
self.maxVSWR = maxVSWR
span = maxVSWR-minVSWR
if span == 0:
span = 0.01
self.span = span
target_ticks = math.floor(self.chartHeight / 60)
if self.logarithmicY:
for i in range(target_ticks):
y = int(self.topMargin + (i / target_ticks) * self.chartHeight)
vswr = self.valueAtPosition(y)[0]
qp.setPen(self.textColor)
if vswr != 0:
digits = max(0, min(2, math.floor(3 - math.log10(abs(vswr)))))
if digits == 0:
vswrstr = str(round(vswr))
else:
vswrstr = str(round(vswr, digits))
qp.drawText(3, y+3, vswrstr)
qp.setPen(QtGui.QPen(self.foregroundColor))
qp.drawLine(self.leftMargin-5, y, self.leftMargin+self.chartWidth, y)
qp.drawLine(self.leftMargin - 5, self.topMargin + self.chartHeight,
self.leftMargin + self.chartWidth, self.topMargin + self.chartHeight)
qp.setPen(self.textColor)
digits = max(0, min(2, math.floor(3 - math.log10(abs(minVSWR)))))
if digits == 0:
vswrstr = str(round(minVSWR))
else:
vswrstr = str(round(minVSWR, digits))
qp.drawText(3, self.topMargin + self.chartHeight, vswrstr)
else:
for i in range(target_ticks):
vswr = minVSWR + i * self.span/target_ticks
y = self.getYPositionFromValue(vswr)
qp.setPen(self.textColor)
if vswr != 0:
digits = max(0, min(2, math.floor(3 - math.log10(abs(vswr)))))
if digits == 0:
vswrstr = str(round(vswr))
else:
vswrstr = str(round(vswr, digits))
qp.drawText(3, y+3, vswrstr)
qp.setPen(QtGui.QPen(self.foregroundColor))
qp.drawLine(self.leftMargin-5, y, self.leftMargin+self.chartWidth, y)
qp.drawLine(self.leftMargin - 5,
self.topMargin,
self.leftMargin + self.chartWidth,
self.topMargin)
qp.setPen(self.textColor)
digits = max(0, min(2, math.floor(3 - math.log10(abs(maxVSWR)))))
if digits == 0:
vswrstr = str(round(maxVSWR))
else:
vswrstr = str(round(maxVSWR, digits))
qp.drawText(3, 35, vswrstr)
self.drawFrequencyTicks(qp)
qp.setPen(self.swrColor)
for vswr in self.swrMarkers:
y = self.getYPositionFromValue(vswr)
qp.drawLine(self.leftMargin, y, self.leftMargin + self.chartWidth, y)
qp.drawText(self.leftMargin + 3, y - 1, str(vswr))
self.drawData(qp, self.data, self.sweepColor)
self.drawData(qp, self.reference, self.referenceColor)
self.drawMarkers(qp)
def getYPositionFromValue(self, vswr) -> int:
if self.logarithmicY:
min_val = self.maxVSWR - self.span
if self.maxVSWR > 0 and min_val > 0 and vswr > 0:
span = math.log(self.maxVSWR) - math.log(min_val)
else:
return -1
return (
self.topMargin +
round((math.log(self.maxVSWR) - math.log(vswr)) / span * self.chartHeight))
return self.topMargin + round((self.maxVSWR - vswr) / self.span * self.chartHeight)
def getYPosition(self, d: Datapoint) -> int:
return self.getYPositionFromValue(d.vswr)
def valueAtPosition(self, y) -> List[float]:
absy = y - self.topMargin
if self.logarithmicY:
min_val = self.maxVSWR - self.span
if self.maxVSWR > 0 and min_val > 0:
span = math.log(self.maxVSWR) - math.log(min_val)
step = span / self.chartHeight
val = math.exp(math.log(self.maxVSWR) - absy * step)
else:
val = -1
else:
val = -1 * ((absy / self.chartHeight * self.span) - self.maxVSWR)
return [val]
def resetDisplayLimits(self):
self.maxDisplayValue = 25
self.logarithmicY = False
super().resetDisplayLimits()
