Move project, add simple test

Software/PC_Application/LibreVNA-GUI/unit.cpp

@@ -0,0 +1,93 @@
+#include "unit.h"
+
+#include <math.h>
+#include <sstream>
+#include <iomanip>
+#include <QDebug>
+
+using namespace std;
+
+double Unit::FromString(QString string, QString unit, QString prefixes)
+{
+    if(string.size() == 0) {
+        return std::numeric_limits<double>::quiet_NaN();
+    }
+    // remove unit if present
+    if(string.endsWith(unit, Qt::CaseInsensitive)) {
+        string.chop(unit.size());
+    }
+    // check if last char is a valid prefix
+    double factor = 1.0;
+    if(prefixes.contains(string.at(string.size()-1))) {
+        QChar prefix = string.at(string.size()-1);
+        factor = SIPrefixToFactor(prefix.toLatin1());
+        string.chop(1);
+    }
+    bool convertOk;
+    auto value = string.toDouble(&convertOk);
+    if(!convertOk) {
+        return std::numeric_limits<double>::quiet_NaN();
+    }
+    return value * factor;
+}
+
+QString Unit::ToString(double value, QString unit, QString prefixes, int precision)
+{
+    // change label text
+    QString sValue;
+    if(isnan(value) || isinf(value)) {
+        sValue.append("NaN");
+        return sValue;
+    } else if(abs(value) <= numeric_limits<double>::epsilon()) {
+        sValue.append("0 ");
+    } else {
+        if(value < 0) {
+            sValue.append('-');
+            value = -value;
+        }
+        int prefixIndex = 0; //prefixes.indexOf(' ');
+        int preDotDigits = log10(value / SIPrefixToFactor(prefixes[prefixIndex].toLatin1())) + 1;
+        while(preDotDigits > 3 && prefixIndex < prefixes.length() - 1) {
+            prefixIndex++;
+            preDotDigits = log10(value / SIPrefixToFactor(prefixes[prefixIndex].toLatin1())) + 1;
+        }
+        value /= SIPrefixToFactor(prefixes[prefixIndex].toLatin1());
+        stringstream ss;
+        ss << std::fixed;
+        if(precision < 0) {
+            precision = 0;
+        }
+        if(preDotDigits >= 0) {
+            if(precision - preDotDigits < 0) {
+                ss << std::setprecision(0);
+            } else {
+                ss << std::setprecision(precision - preDotDigits);
+            }
+        } else {
+            ss << std::setprecision(precision - 2);
+        }
+        ss << value;
+        sValue.append(QString::fromStdString(ss.str()));
+        sValue.append(prefixes[prefixIndex]);
+    }
+    sValue.append(unit);
+    return sValue;
+}
+
+double Unit::SIPrefixToFactor(char prefix)
+{
+    switch(prefix) {
+    case 'f': return 1e-15; break;
+    case 'p': return 1e-12; break;
+    case 'n': return 1e-9; break;
+    case 'u': return 1e-6; break;
+    case 'm': return 1e-3; break;
+    case ' ': return 1e0; break;
+    case 'k': return 1e3; break;
+    case 'M': return 1e6; break;
+    case 'G': return 1e9; break;
+    case 'T': return 1e12; break;
+    case 'P': return 1e15; break;
+    default: return 1e0; break;
+    }
+}