Neither Json.NET nor the JSON standard have a predefined format for complex numbers, and so Json.NET will serialize all the properties of a Complex, generating the output you see. To get clean JSON with just the necessary data, you will need to write a custom JsonConverter that serializes a Complex from and to JSON.
However, what format should be used? Options might include:
- As an array:
[0.0017923713150000001,0.0].
- As an object with
"Real" and "Imaginary" properties: {"Real":0.0017923713150000001,"Imaginary":0.0}.
- In math.js format:
{"mathjs":"Complex","re":0.0017923713150000001,"im":0.0}.
Here are converters for each of these formats:
public abstract class ComplexConverterBase : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return objectType == typeof(Complex) || objectType == typeof(Complex?);
}
}
public class ComplexArrayConverter : ComplexConverterBase
{
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
var array = serializer.Deserialize<double[]>(reader);
if (array.Length != 2)
{
throw new JsonSerializationException(string.Format("Invalid complex number array of length {0}", array.Length));
}
return new Complex(array[0], array[1]);
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
var complex = (Complex)value;
writer.WriteStartArray();
writer.WriteValue(complex.Real);
writer.WriteValue(complex.Imaginary);
writer.WriteEndArray();
}
}
public class ComplexObjectConverter : ComplexConverterBase
{
// By using a surrogate type, we respect the naming conventions of the serializer's contract resolver.
class ComplexSurrogate
{
public double Real { get; set; }
public double Imaginary { get; set; }
public static implicit operator Complex(ComplexSurrogate surrogate)
{
if (surrogate == null)
return default(Complex);
return new Complex(surrogate.Real, surrogate.Imaginary);
}
public static implicit operator ComplexSurrogate(Complex complex)
{
return new ComplexSurrogate { Real = complex.Real, Imaginary = complex.Imaginary };
}
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
return (Complex)serializer.Deserialize<ComplexSurrogate>(reader);
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
serializer.Serialize(writer, (ComplexSurrogate)(Complex)value);
}
}
public class ComplexMathJSConverter : ComplexConverterBase
{
// Serialize in math.js format
// http://mathjs.org/docs/core/serialization.html
// By using a surrogate type, we respect the naming conventions of the serializer's contract resolver.
class ComplexSurrogate
{
[JsonProperty(Order = 1)]
public double re { get; set; }
[JsonProperty(Order = 2)]
public double im { get; set; }
[JsonProperty(Order = 0)]
public string mathjs { get { return "Complex"; } }
public static implicit operator Complex(ComplexSurrogate surrogate)
{
if (surrogate == null)
return default(Complex);
return new Complex(surrogate.re, surrogate.im);
}
public static implicit operator ComplexSurrogate(Complex complex)
{
return new ComplexSurrogate { re = complex.Real, im = complex.Imaginary };
}
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
return (Complex)serializer.Deserialize<ComplexSurrogate>(reader);
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
serializer.Serialize(writer, (ComplexSurrogate)(Complex)value);
}
}
Then, you would serialize as follows:
var settings = new JsonSerializerSettings
{
// Add a complex converter to the Converts array.
// Use one of ComplexArrayConverter, ComplexMathJSConverter and ComplexObjectConverter
Converters = { new ComplexArrayConverter() },
};
var json = JsonConvert.SerializeObject(calculation, settings);
To use the converter in global settings, see here for Web API or here when calling the serializer directly.
Sample fiddle.
