86 lines
3.1 KiB
Markdown
86 lines
3.1 KiB
Markdown
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# MathClassify
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Determines the type of a real number and returns a result as a value from the [ENUM_FP_CLASS](/en/docs/math/mathclassify#enum_fp_class) enumeration
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```
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ENUM_FP_CLASS MathClassify(
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double value // real number
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);
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```
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Parameters
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value
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[in] The real number to be checked
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Return Value
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A value from the ENUM_FP_CLASS enumeration
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ENUM_FP_CLASS
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| ID | Description |
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| --- | --- |
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| FP_SUBNORMAL | A subnormal number which is closer to zero than the smallest representable normal number DBL_MIN (2.2250738585072014e-308) |
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| FP_NORMAL | A normal number in the range between 2.2250738585072014e-308 and 1.7976931348623158e+308 |
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| FP_ZERO | A positive or a negative zero |
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| FP_INFINITE | A number which cannot be represented by the appropriate type, positive or negative infinity |
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| FP_NAN | Not a number. |
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Example:
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```
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//+------------------------------------------------------------------+
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//| Script program start function |
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//+------------------------------------------------------------------+
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void OnStart()
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{
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//--- test NaN
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double nan=double("nan");
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PrintFormat("Test NaN: %G is %s, MathIsValidNumber(NaN)=%s",
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nan,
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EnumToString(MathClassify(nan)),
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(string)MathIsValidNumber(nan));
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//--- test infinity
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double inf=double("inf");
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PrintFormat("Test Inf: %G is %s, MathIsValidNumber(inf)=%s",
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inf,
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EnumToString(MathClassify(inf)),
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(string)MathIsValidNumber(inf));
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//--- test normal value
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double normal=1.2345e6;
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PrintFormat("Test Normal: %G is %s, MathIsValidNumber(normal)=%s",
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normal,
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EnumToString(MathClassify(normal)),
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(string)MathIsValidNumber(normal));
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//--- test subnormal value
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double sub_normal=DBL_MIN/2.0;
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PrintFormat("Test Subnormal: %G is %s, MathIsValidNumber(sub_normal)=%s",
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sub_normal,
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EnumToString(MathClassify(sub_normal)),
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(string)MathIsValidNumber(sub_normal));
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//--- test zero value
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double zero=0.0/(-1);
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PrintFormat("Test Zero: %G is %s, MathIsValidNumber(zero)=%s",
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zero,
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EnumToString(MathClassify(zero)),
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(string)MathIsValidNumber(zero));
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}
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/*
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Result:
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Test NaN: NAN is FP_NAN, MathIsValidNumber(NaN)=false
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Test Inf: INF is FP_INFINITE, MathIsValidNumber(inf)=false
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Test Normal: 1.2345E+06 is FP_NORMAL, MathIsValidNumber(normal)=true
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Test Subnormal: 1.11254E-308 is FP_SUBNORMAL, MathIsValidNumber(sub_normal)=true
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Test Zero: -0 is FP_ZERO, MathIsValidNumber(zero)=true
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*/
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//+------------------------------------------------------------------+
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```
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See also
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[Real types (double, float)](/en/docs/basis/types/double), [MathIsValidNumber](/en/docs/math/mathisvalidnumber)
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