what is this type "sfix16_Sp1_Bn25"

What is

"sfix16_Sp1_Bn25" this type mean for?

Answer 1

[Manish]

Hi dayoung,

Here is the breakdown of the data type:

• sfix: Signed Fixed-Point data type.
• S: slope
• P: Decimal point
• B: Bias
• n: Negative

Therefore, "sfix16_Sp1_Bn25" describes a signed 16-bit fixed-point number with a slope of 0.1 and a bias of -25.

Here is the documentation link:

• https://www.mathworks.com/help/fixedpoint/ug/fixed-point-numbers.html

Hope it helps!

Answer 2

[Andy Bartlett]

Tip: Feed Simulink Type Name to numerictype

If the type name corresponds to a numeric type (not a Bus, Enum, Alias, or user custom type), then feed the string to numerictype to get a numerictype object that explains the details.

nt1 = numerictype("sfix16_Sp1_Bn25")

nt1 =


          DataTypeMode: Fixed-point: slope and bias scaling
            Signedness: Signed
            WordLength: 16
                 Slope: 0.1
                  Bias: -25

nt2 = numerictype("ufix7_En5")

nt2 =


          DataTypeMode: Fixed-point: binary point scaling
            Signedness: Unsigned
            WordLength: 7
        FractionLength: 5

nt3 = numerictype('single')

nt3 =


          DataTypeMode: Single

Tip 2: fixed.extractNumericType can also be used and is more general

fixed.extractNumericType can convert many inputs to its numerictype object. See it's help for more info.

nt4 = fixed.extractNumericType('half')

nt4 =


          DataTypeMode: Half

nt5 = fixed.extractNumericType("flts8_E6")

nt5 =


          DataTypeMode: Scaled double: binary point scaling
            Signedness: Signed
            WordLength: 8
        FractionLength: -6

Tip 3: fixdt also works except for scaled doubles

nt6 = fixdt('sfix123_S4_B5')

nt6 = 
  NumericType with properties:

    DataTypeMode: 'Fixed-point: slope and bias scaling'
      Signedness: 'Signed'
      WordLength: 123
           Slope: 4
            Bias: 5
         IsAlias: 0
       DataScope: 'Auto'
      HeaderFile: ''
     Description: ''