Math.Exp メソッド
アセンブリ: mscorlib (mscorlib.dll 内)

Dim d As Double Dim returnValue As Double returnValue = Math.Exp(d)
戻り値
数値 e を d で累乗した値。d が NaN または PositiveInfinity のいずれかに等しい場合は、その値が返されます。d が NegativeInfinity に等しい場合は、0 が返されます。


次に示すのは、Exp を使用して、選択した値から対数恒等式を求める例です。
' Example for the Math.Exp( Double ) method. Imports System Imports Microsoft.VisualBasic Module ExpDemo Sub Main() Console.WriteLine( _ "This example of Math.Exp( Double ) " & _ "generates the following output." & vbCrLf) Console.WriteLine( _ "Evaluate [e ^ ln(X) == ln(e ^ X) == X] " & _ "with selected values for X:") UseLnExp(0.1) UseLnExp(1.2) UseLnExp(4.9) UseLnExp(9.9) Console.WriteLine( vbCrLf & _ "Evaluate these identities with selected values for X and Y:") Console.WriteLine(" (e ^ X) * (e ^ Y) = e ^ (X + Y)") Console.WriteLine(" (e ^ X) ^ Y = e ^ (X * Y)") Console.WriteLine(" X ^ Y = e ^ (Y * ln(X))") UseTwoArgs(0.1, 1.2) UseTwoArgs(1.2, 4.9) UseTwoArgs(4.9, 9.9) End Sub 'Main ' Evaluate logarithmic/exponential identity with a given argument. Sub UseLnExp(arg As Double) ' Evaluate e ^ ln(X) = ln(e ^ X) = X. Console.WriteLine( _ vbCrLf & " Math.Exp(Math.Log({0})) = {1:E16}" + _ vbCrLf & " Math.Log(Math.Exp({0})) = {2:E16}", _ arg, Math.Exp(Math.Log(arg)), Math.Log(Math.Exp(arg))) End Sub 'UseLnExp ' Evaluate exponential identities that are functions of two arguments. Sub UseTwoArgs(argX As Double, argY As Double) ' Evaluate (e ^ X) * (e ^ Y) = e ^ (X + Y). Console.WriteLine( _ vbCrLf & "Math.Exp({0}) * Math.Exp({1}) = {2:E16}" + _ vbCrLf & " Math.Exp({0} + {1}) = {3:E16}", _ argX, argY, Math.Exp(argX) * Math.Exp(argY), _ Math.Exp((argX + argY))) ' Evaluate (e ^ X) ^ Y = e ^ (X * Y). Console.WriteLine( _ " Math.Pow(Math.Exp({0}), {1}) = {2:E16}" + _ vbCrLf & " Math.Exp({0} * {1}) = {3:E16}", _ argX, argY, Math.Pow(Math.Exp(argX), argY), _ Math.Exp((argX * argY))) ' Evaluate X ^ Y = e ^ (Y * ln(X)). Console.WriteLine( _ " Math.Pow({0}, {1}) = {2:E16}" + _ vbCrLf & "Math.Exp({1} * Math.Log({0})) = {3:E16}", _ argX, argY, Math.Pow(argX, argY), _ Math.Exp((argY * Math.Log(argX)))) End Sub 'UseTwoArgs End Module 'ExpDemo ' This example of Math.Exp( Double ) generates the following output. ' ' Evaluate [e ^ ln(X) == ln(e ^ X) == X] with selected values for X: ' ' Math.Exp(Math.Log(0.1)) = 1.0000000000000001E-001 ' Math.Log(Math.Exp(0.1)) = 1.0000000000000008E-001 ' ' Math.Exp(Math.Log(1.2)) = 1.2000000000000000E+000 ' Math.Log(Math.Exp(1.2)) = 1.2000000000000000E+000 ' ' Math.Exp(Math.Log(4.9)) = 4.9000000000000012E+000 ' Math.Log(Math.Exp(4.9)) = 4.9000000000000004E+000 ' ' Math.Exp(Math.Log(9.9)) = 9.9000000000000004E+000 ' Math.Log(Math.Exp(9.9)) = 9.9000000000000004E+000 ' ' Evaluate these identities with selected values for X and Y: ' (e ^ X) * (e ^ Y) = e ^ (X + Y) ' (e ^ X) ^ Y = e ^ (X * Y) ' X ^ Y = e ^ (Y * ln(X)) ' ' Math.Exp(0.1) * Math.Exp(1.2) = 3.6692966676192444E+000 ' Math.Exp(0.1 + 1.2) = 3.6692966676192444E+000 ' Math.Pow(Math.Exp(0.1), 1.2) = 1.1274968515793757E+000 ' Math.Exp(0.1 * 1.2) = 1.1274968515793757E+000 ' Math.Pow(0.1, 1.2) = 6.3095734448019331E-002 ' Math.Exp(1.2 * Math.Log(0.1)) = 6.3095734448019344E-002 ' ' Math.Exp(1.2) * Math.Exp(4.9) = 4.4585777008251705E+002 ' Math.Exp(1.2 + 4.9) = 4.4585777008251716E+002 ' Math.Pow(Math.Exp(1.2), 4.9) = 3.5780924170885260E+002 ' Math.Exp(1.2 * 4.9) = 3.5780924170885277E+002 ' Math.Pow(1.2, 4.9) = 2.4433636334442981E+000 ' Math.Exp(4.9 * Math.Log(1.2)) = 2.4433636334442981E+000 ' ' Math.Exp(4.9) * Math.Exp(9.9) = 2.6764450551890982E+006 ' Math.Exp(4.9 + 9.9) = 2.6764450551891015E+006 ' Math.Pow(Math.Exp(4.9), 9.9) = 1.1684908531676833E+021 ' Math.Exp(4.9 * 9.9) = 1.1684908531676829E+021 ' Math.Pow(4.9, 9.9) = 6.8067718210957060E+006 ' Math.Exp(9.9 * Math.Log(4.9)) = 6.8067718210956985E+006
// Example for the Math.Exp( double ) method. using System; class ExpDemo { public static void Main() { Console.WriteLine( "This example of Math.Exp( double ) " + "generates the following output.\n" ); Console.WriteLine( "Evaluate [e ^ ln(X) == ln(e ^ X) == X] " + "with selected values for X:" ); UseLnExp(0.1); UseLnExp(1.2); UseLnExp(4.9); UseLnExp(9.9); Console.WriteLine( "\nEvaluate these identities with " + "selected values for X and Y:" ); Console.WriteLine( " (e ^ X) * (e ^ Y) == e ^ (X + Y)" ); Console.WriteLine( " (e ^ X) ^ Y == e ^ (X * Y)" ); Console.WriteLine( " X ^ Y == e ^ (Y * ln(X))" ); UseTwoArgs(0.1, 1.2); UseTwoArgs(1.2, 4.9); UseTwoArgs(4.9, 9.9); } // Evaluate logarithmic/exponential identity with a given argument. static void UseLnExp(double arg) { // Evaluate e ^ ln(X) == ln(e ^ X) == X. Console.WriteLine( "\n Math.Exp(Math.Log({0})) == {1:E16}\n" + " Math.Log(Math.Exp({0})) == {2:E16}", arg, Math.Exp(Math.Log(arg)), Math.Log(Math.Exp(arg)) ); } // Evaluate exponential identities that are functions of two arguments. static void UseTwoArgs(double argX, double argY) { // Evaluate (e ^ X) * (e ^ Y) == e ^ (X + Y). Console.WriteLine( "\nMath.Exp({0}) * Math.Exp({1}) == {2:E16}" + "\n Math.Exp({0} + {1}) == {3:E16}", argX, argY, Math.Exp(argX) * Math.Exp(argY), Math.Exp(argX + argY) ); // Evaluate (e ^ X) ^ Y == e ^ (X * Y). Console.WriteLine( " Math.Pow(Math.Exp({0}), {1}) == {2:E16}" + "\n Math.Exp({0} * {1}) == {3:E16}", argX, argY, Math.Pow(Math.Exp(argX), argY), Math.Exp(argX * argY) ); // Evaluate X ^ Y == e ^ (Y * ln(X)). Console.WriteLine( " Math.Pow({0}, {1}) == {2:E16}" + "\nMath.Exp({1} * Math.Log({0})) == {3:E16}", argX, argY, Math.Pow(argX, argY), Math.Exp(argY * Math.Log(argX)) ); } } /* This example of Math.Exp( double ) generates the following output. Evaluate [e ^ ln(X) == ln(e ^ X) == X] with selected values for X: Math.Exp(Math.Log(0.1)) == 1.0000000000000001E-001 Math.Log(Math.Exp(0.1)) == 1.0000000000000008E-001 Math.Exp(Math.Log(1.2)) == 1.2000000000000000E+000 Math.Log(Math.Exp(1.2)) == 1.2000000000000000E+000 Math.Exp(Math.Log(4.9)) == 4.9000000000000012E+000 Math.Log(Math.Exp(4.9)) == 4.9000000000000004E+000 Math.Exp(Math.Log(9.9)) == 9.9000000000000004E+000 Math.Log(Math.Exp(9.9)) == 9.9000000000000004E+000 Evaluate these identities with selected values for X and Y: (e ^ X) * (e ^ Y) == e ^ (X + Y) (e ^ X) ^ Y == e ^ (X * Y) X ^ Y == e ^ (Y * ln(X)) Math.Exp(0.1) * Math.Exp(1.2) == 3.6692966676192444E+000 Math.Exp(0.1 + 1.2) == 3.6692966676192444E+000 Math.Pow(Math.Exp(0.1), 1.2) == 1.1274968515793757E+000 Math.Exp(0.1 * 1.2) == 1.1274968515793757E+000 Math.Pow(0.1, 1.2) == 6.3095734448019331E-002 Math.Exp(1.2 * Math.Log(0.1)) == 6.3095734448019344E-002 Math.Exp(1.2) * Math.Exp(4.9) == 4.4585777008251705E+002 Math.Exp(1.2 + 4.9) == 4.4585777008251716E+002 Math.Pow(Math.Exp(1.2), 4.9) == 3.5780924170885260E+002 Math.Exp(1.2 * 4.9) == 3.5780924170885277E+002 Math.Pow(1.2, 4.9) == 2.4433636334442981E+000 Math.Exp(4.9 * Math.Log(1.2)) == 2.4433636334442981E+000 Math.Exp(4.9) * Math.Exp(9.9) == 2.6764450551890982E+006 Math.Exp(4.9 + 9.9) == 2.6764450551891015E+006 Math.Pow(Math.Exp(4.9), 9.9) == 1.1684908531676833E+021 Math.Exp(4.9 * 9.9) == 1.1684908531676829E+021 Math.Pow(4.9, 9.9) == 6.8067718210957060E+006 Math.Exp(9.9 * Math.Log(4.9)) == 6.8067718210956985E+006 */
// Example for the Math::Exp( double ) method. using namespace System; // Evaluate logarithmic/exponential identity with a given argument. void UseLnExp( double arg ) { // Evaluate e ^ ln(X) == ln(e ^ X) == X. Console::WriteLine( "\n Math::Exp(Math::Log({0})) == {1:E16}\n" " Math::Log(Math::Exp({0})) == {2:E16}", arg, Math::Exp( Math::Log( arg ) ), Math::Log( Math::Exp( arg ) ) ); } // Evaluate exponential identities that are functions of two arguments. void UseTwoArgs( double argX, double argY ) { // Evaluate (e ^ X) * (e ^ Y) == e ^ (X + Y). Console::WriteLine( "\nMath::Exp({0}) * Math::Exp({1}) == {2:E16}" "\n Math::Exp({0} + {1}) == {3:E16}", argX, argY, Math::Exp( argX ) * Math::Exp( argY ), Math::Exp( argX + argY ) ); // Evaluate (e ^ X) ^ Y == e ^ (X * Y). Console::WriteLine( " Math::Pow(Math::Exp({0}), {1}) == {2:E16}" "\n Math::Exp({0} * {1}) == {3:E16}", argX, argY, Math::Pow( Math::Exp( argX ), argY ), Math::Exp( argX * argY ) ); // Evaluate X ^ Y == e ^ (Y * ln(X)). Console::WriteLine( " Math::Pow({0}, {1}) == {2:E16}" "\nMath::Exp({1} * Math::Log({0})) == {3:E16}", argX, argY, Math::Pow( argX, argY ), Math::Exp( argY * Math::Log( argX ) ) ); } int main() { Console::WriteLine( "This example of Math::Exp( double ) " "generates the following output.\n" ); Console::WriteLine( "Evaluate [e ^ ln(X) == ln(e ^ X) == X] " "with selected values for X:" ); UseLnExp( 0.1 ); UseLnExp( 1.2 ); UseLnExp( 4.9 ); UseLnExp( 9.9 ); Console::WriteLine( "\nEvaluate these identities with " "selected values for X and Y:" ); Console::WriteLine( " (e ^ X) * (e ^ Y) == e ^ (X + Y)" ); Console::WriteLine( " (e ^ X) ^ Y == e ^ (X * Y)" ); Console::WriteLine( " X ^ Y == e ^ (Y * ln(X))" ); UseTwoArgs( 0.1, 1.2 ); UseTwoArgs( 1.2, 4.9 ); UseTwoArgs( 4.9, 9.9 ); } /* This example of Math::Exp( double ) generates the following output. Evaluate [e ^ ln(X) == ln(e ^ X) == X] with selected values for X: Math::Exp(Math::Log(0.1)) == 1.0000000000000001E-001 Math::Log(Math::Exp(0.1)) == 1.0000000000000008E-001 Math::Exp(Math::Log(1.2)) == 1.2000000000000000E+000 Math::Log(Math::Exp(1.2)) == 1.2000000000000000E+000 Math::Exp(Math::Log(4.9)) == 4.9000000000000012E+000 Math::Log(Math::Exp(4.9)) == 4.9000000000000004E+000 Math::Exp(Math::Log(9.9)) == 9.9000000000000004E+000 Math::Log(Math::Exp(9.9)) == 9.9000000000000004E+000 Evaluate these identities with selected values for X and Y: (e ^ X) * (e ^ Y) == e ^ (X + Y) (e ^ X) ^ Y == e ^ (X * Y) X ^ Y == e ^ (Y * ln(X)) Math::Exp(0.1) * Math::Exp(1.2) == 3.6692966676192444E+000 Math::Exp(0.1 + 1.2) == 3.6692966676192444E+000 Math::Pow(Math::Exp(0.1), 1.2) == 1.1274968515793757E+000 Math::Exp(0.1 * 1.2) == 1.1274968515793757E+000 Math::Pow(0.1, 1.2) == 6.3095734448019331E-002 Math::Exp(1.2 * Math::Log(0.1)) == 6.3095734448019344E-002 Math::Exp(1.2) * Math::Exp(4.9) == 4.4585777008251705E+002 Math::Exp(1.2 + 4.9) == 4.4585777008251716E+002 Math::Pow(Math::Exp(1.2), 4.9) == 3.5780924170885260E+002 Math::Exp(1.2 * 4.9) == 3.5780924170885277E+002 Math::Pow(1.2, 4.9) == 2.4433636334442981E+000 Math::Exp(4.9 * Math::Log(1.2)) == 2.4433636334442981E+000 Math::Exp(4.9) * Math::Exp(9.9) == 2.6764450551890982E+006 Math::Exp(4.9 + 9.9) == 2.6764450551891015E+006 Math::Pow(Math::Exp(4.9), 9.9) == 1.1684908531676833E+021 Math::Exp(4.9 * 9.9) == 1.1684908531676829E+021 Math::Pow(4.9, 9.9) == 6.8067718210957060E+006 Math::Exp(9.9 * Math::Log(4.9)) == 6.8067718210956985E+006 */
// Example for the Math.Exp( double ) method. import System.*; class ExpDemo { public static void main(String[] args) { Console.WriteLine(("This example of Math.Exp( double ) " + "generates the following output.\n")); Console.WriteLine(("Evaluate [e ^ ln(X) == ln(e ^ X) == X] " + "with selected values for X:")); UseLnExp(0.1); UseLnExp(1.2); UseLnExp(4.9); UseLnExp(9.9); Console.WriteLine(("\nEvaluate these identities with " + "selected values for X and Y:")); Console.WriteLine(" (e ^ X) * (e ^ Y) == e ^ (X + Y)"); Console.WriteLine(" (e ^ X) ^ Y == e ^ (X * Y)"); Console.WriteLine(" X ^ Y == e ^ (Y * ln(X))"); UseTwoArgs(0.1, 1.2); UseTwoArgs(1.2, 4.9); UseTwoArgs(4.9, 9.9); } //main // Evaluate logarithmic/exponential identity with a given argument. static void UseLnExp(double arg) { // Evaluate e ^ ln(X) == ln(e ^ X) == X. Console.WriteLine("\n Math.Exp(Math.Log({0})) == {1}\n" + " Math.Log(Math.Exp({0})) == {2}", System.Convert.ToString(arg), ((System.Double)System.Math.Exp( System.Math.Log(arg))).ToString("E16"), ((System.Double)System.Math.Log( System.Math.Exp(arg))).ToString("E16")); } //UseLnExp // Evaluate exponential identities that are functions of two arguments. static void UseTwoArgs(double argX, double argY) { // Evaluate (e ^ X) * (e ^ Y) == e ^ (X + Y). Console.WriteLine("\nMath.Exp({0}) * Math.Exp({1}) == {2}" + "\n Math.Exp({0} + {1}) == {3}", new Object[] {System.Convert.ToString(argX), System.Convert.ToString(argY),((System.Double ) (System.Math.Exp(argX) * System.Math.Exp(argY))).ToString("E16") , ((System.Double )System.Math.Exp((argX + argY))).ToString("E16")}); // Evaluate (e ^ X) ^ Y == e ^ (X * Y). Console.WriteLine(" Math.Pow(Math.Exp({0}), {1}) == {2}" + "\n Math.Exp({0} * {1}) == {3}", new Object[] { System.Convert.ToString(argX), System.Convert.ToString(argY),((System.Double)System.Math.Pow (System.Math.Exp(argX),argY)).ToString("E16"), ((System.Double)System.Math.Exp((argX * argY))).ToString("E16")}); // Evaluate X ^ Y == e ^ (Y * ln(X)). Console.WriteLine(" Math.Pow({0}, {1}) == {2}" + "\nMath.Exp({1} * Math.Log({0})) == {3}", new Object[] { System.Convert.ToString(argX), System.Convert.ToString(argY), ((System.Double)System.Math.Pow(argX, argY)).ToString("E16") , ((System.Double)System.Math.Exp( (argY * System.Math.Log(argX)))).ToString("E16") }); } //UseTwoArgs } //ExpDemo /* This example of Math.Exp( double ) generates the following output. Evaluate [e ^ ln(X) == ln(e ^ X) == X] with selected values for X: Math.Exp(Math.Log(0.1)) == 1.0000000000000001E-001 Math.Log(Math.Exp(0.1)) == 1.0000000000000008E-001 Math.Exp(Math.Log(1.2)) == 1.2000000000000000E+000 Math.Log(Math.Exp(1.2)) == 1.2000000000000000E+000 Math.Exp(Math.Log(4.9)) == 4.9000000000000012E+000 Math.Log(Math.Exp(4.9)) == 4.9000000000000004E+000 Math.Exp(Math.Log(9.9)) == 9.9000000000000004E+000 Math.Log(Math.Exp(9.9)) == 9.9000000000000004E+000 Evaluate these identities with selected values for X and Y: (e ^ X) * (e ^ Y) == e ^ (X + Y) (e ^ X) ^ Y == e ^ (X * Y) X ^ Y == e ^ (Y * ln(X)) Math.Exp(0.1) * Math.Exp(1.2) == 3.6692966676192444E+000 Math.Exp(0.1 + 1.2) == 3.6692966676192444E+000 Math.Pow(Math.Exp(0.1), 1.2) == 1.1274968515793757E+000 Math.Exp(0.1 * 1.2) == 1.1274968515793757E+000 Math.Pow(0.1, 1.2) == 6.3095734448019331E-002 Math.Exp(1.2 * Math.Log(0.1)) == 6.3095734448019344E-002 Math.Exp(1.2) * Math.Exp(4.9) == 4.4585777008251705E+002 Math.Exp(1.2 + 4.9) == 4.4585777008251716E+002 Math.Pow(Math.Exp(1.2), 4.9) == 3.5780924170885260E+002 Math.Exp(1.2 * 4.9) == 3.5780924170885277E+002 Math.Pow(1.2, 4.9) == 2.4433636334442981E+000 Math.Exp(4.9 * Math.Log(1.2)) == 2.4433636334442981E+000 Math.Exp(4.9) * Math.Exp(9.9) == 2.6764450551890982E+006 Math.Exp(4.9 + 9.9) == 2.6764450551891015E+006 Math.Pow(Math.Exp(4.9), 9.9) == 1.1684908531676833E+021 Math.Exp(4.9 * 9.9) == 1.1684908531676829E+021 Math.Pow(4.9, 9.9) == 6.8067718210957060E+006 Math.Exp(9.9 * Math.Log(4.9)) == 6.8067718210956985E+006 */

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