彻底改版2.0

third/3rd_qwt/qwt_transform.cpp

@@ -0,0 +1,177 @@
+/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
+ * Qwt Widget Library
+ * Copyright (C) 1997   Josef Wilgen
+ * Copyright (C) 2002   Uwe Rathmann
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the Qwt License, Version 1.0
+ *****************************************************************************/
+
+#include "qwt_transform.h"
+#include "qwt_math.h"
+
+#if QT_VERSION < 0x040601
+#define qExp(x) ::exp(x)
+#endif
+
+#if QT_VERSION >= 0x050400
+
+//! Smallest allowed value for logarithmic scales: 1.0e-150
+const double QwtLogTransform::LogMin = 1.0e-150;
+
+//! Largest allowed value for logarithmic scales: 1.0e150
+const double QwtLogTransform::LogMax = 1.0e150;
+
+#else
+
+//! Smallest allowed value for logarithmic scales: 1.0e-150
+QT_STATIC_CONST_IMPL double QwtLogTransform::LogMin = 1.0e-150;
+
+//! Largest allowed value for logarithmic scales: 1.0e150
+QT_STATIC_CONST_IMPL double QwtLogTransform::LogMax = 1.0e150;
+
+#endif
+
+//! Constructor
+QwtTransform::QwtTransform()
+{
+}
+
+//! Destructor
+QwtTransform::~QwtTransform()
+{
+}
+
+/*!
+  \param value Value to be bounded
+  \return value unmodified
+ */
+double QwtTransform::bounded( double value ) const
+{
+    return value;
+}
+
+//! Constructor
+QwtNullTransform::QwtNullTransform():
+    QwtTransform()
+{
+}
+
+//! Destructor
+QwtNullTransform::~QwtNullTransform()
+{
+}
+
+/*!
+  \param value Value to be transformed
+  \return value unmodified
+ */
+double QwtNullTransform::transform( double value ) const
+{
+    return value;
+}
+
+/*!
+  \param value Value to be transformed
+  \return value unmodified
+ */
+double QwtNullTransform::invTransform( double value ) const
+{
+    return value;
+}
+
+//! \return Clone of the transformation
+QwtTransform *QwtNullTransform::copy() const
+{
+    return new QwtNullTransform();
+}
+
+//! Constructor
+QwtLogTransform::QwtLogTransform():
+    QwtTransform()
+{
+}
+
+//! Destructor
+QwtLogTransform::~QwtLogTransform()
+{
+}
+
+/*!
+  \param value Value to be transformed
+  \return log( value )
+ */
+double QwtLogTransform::transform( double value ) const
+{
+    return ::log( value );
+}
+
+/*!
+  \param value Value to be transformed
+  \return exp( value )
+ */
+double QwtLogTransform::invTransform( double value ) const
+{
+    return qExp( value );
+}
+
+/*!
+  \param value Value to be bounded
+  \return qBound( LogMin, value, LogMax )
+ */
+double QwtLogTransform::bounded( double value ) const
+{
+    return qBound( LogMin, value, LogMax );
+}
+
+//! \return Clone of the transformation
+QwtTransform *QwtLogTransform::copy() const
+{
+    return new QwtLogTransform();
+}
+
+/*!
+  Constructor
+  \param exponent Exponent
+*/
+QwtPowerTransform::QwtPowerTransform( double exponent ):
+    QwtTransform(),
+    d_exponent( exponent )
+{
+}
+
+//! Destructor
+QwtPowerTransform::~QwtPowerTransform()
+{
+}
+
+/*!
+  \param value Value to be transformed
+  \return Exponentiation preserving the sign
+ */
+double QwtPowerTransform::transform( double value ) const
+{
+    if ( value < 0.0 )
+        return -qPow( -value, 1.0 / d_exponent );
+    else
+        return qPow( value, 1.0 / d_exponent );
+
+}
+
+/*!
+  \param value Value to be transformed
+  \return Inverse exponentiation preserving the sign
+ */
+double QwtPowerTransform::invTransform( double value ) const
+{
+    if ( value < 0.0 )
+        return -qPow( -value, d_exponent );
+    else
+        return qPow( value, d_exponent );
+}
+
+//! \return Clone of the transformation
+QwtTransform *QwtPowerTransform::copy() const
+{
+    return new QwtPowerTransform( d_exponent );
+}