fimath Properties
Properties of the fimath
object
fimath
properties determine the rules for performing fixed-point
arithmetic operations on fi
objects. fimath
properties are,
by transitivity, also properties of the fi
object. You can set these
properties for individual fi
objects. fimath
object
properties are always writable.
Sum Data Type Properties
CastBeforeSum
— Whether both operands are cast to the sum data type before addition
0
(false
) (default) | 1
(true
)
Whether both operands are cast to the sum data type before addition, specified as one of these values:
0
(false
) — Do not cast before sum1
(true
) — Cast before sum
Note
This property is hidden when the SumMode
is set to
FullPrecision
.
MaxSumWordLength
— Maximum allowable word length for the sum data type
65535
(default) | positive integer
Maximum allowable word length for the sum data type, specified as a positive integer.
SumBias
— Bias of the sum data type
0
(default) | floating-point number
Bias of the sum data type, specified as a floating-point number.
SumFixedExponent
— Fixed exponent of the sum data type
-30
(default) | positive or negative integer
Fixed exponent of the sum data type, specified as a positive or negative integer.
Note
The SumFractionLength
is the negative of the
SumFixedExponent
. Changing one property changes the
other.
SumFractionLength
— Fraction length of the sum data type in bits
30
(default) | positive or negative integer
Fraction length of the sum data type in bits, specified as a positive or negative integer.
Note
The SumFractionLength
is the negative of the
SumFixedExponent
. Changing one property changes the
other.
SumMode
— How the sum data type is determined
FullPrecision
(default) | KeepLSB
| KeepMSB
| SpecifyPrecision
How the sum data type is determined, specified as one of the following:
FullPrecision
— Keep the full precision of the result.KeepLSB
— Keep least significant bits. Specify the sum data type word length, while the fraction length is set to maintain the least significant bits of the sum.KeepMSB
— Keep most significant bits. Specify the sum data type word length, while the fraction length is set to maintain the most significant bits of the sum and no more fractional bits than necessary.SpecifyPrecision
— Specify the word and fraction lengths or the slope and bias of the sum data type.
SumSlope
— Slope of the sum data type
9.3132e-010
(default) | floating-point number
Slope of the sum data type, specified as a floating-point number.
Note
Changing one of these properties affects the others.
SumSlopeAdjustmentFactor
— Slope adjustment factor of the sum data type
1
(default) | floating-point number greater than or equal to 1 and less than 2
Slope adjustment factor of the sum data type, specified as a floating-point number greater than or equal to 1 and less than 2.
Note
Changing one of these properties affects the others.
SumWordLength
— Word length of the sum data type in bits
32
(default) | positive integer
Word length of the sum data type in bits, specified as a positive integer.
Product Data Type Properties
MaxProductWordLength
— Maximum allowable word length for the product data type
65535
(default) | positive integer
Maximum allowable word length for the product data type, specified as a positive integer.
ProductBias
— Bias of the product data type
0
(default) | floating-point number
Bias of the product data type, specified as a floating-point number.
ProductFixedExponent
— Fixed exponent of the product data type
-30
(default) | positive or negative integer
Fixed exponent of the product data type, specified as a positive or negative integer.
Note
The ProductFractionLength
is the negative of the
ProductFixedExponent
. Change one property changes the
other.
ProductFractionLength
— Fraction length of the product data type in bits
30
(default) | positive or negative integer
Fraction length of the product data type in bits, specified as a positive or negative integer.
Note
The ProductFractionLength
is the negative of the
ProductFixedExponent
. Changing one property changes the
other.
ProductMode
— How the product data type is determined
FullPrecision
(default) | KeepLSB
| KeepMSB
| SpecifyPrecision
How the product data type is determined, specified as one of these values:
FullPrecision
— Keep the full precision of the result.KeepLSB
— Keep least significant bits. Specify the product word length, while the fraction length is set to maintain the least significant bits of the product.KeepMSB
— Keep most significant bits. Specify the product word length, while the fraction length is set to maintain the most significant bits of the product.SpecifyPrecision
— Specify the word and fraction lengths or slope and bias of the product.
ProductSlope
— Slope of the product data type
9.3132e-010
(default) | floating-point number
Slope of the product data type, specified as a floating-point number.
Note
Changing one of these properties affects the others.
ProductSlopeAdjustmentFactor
— Slope adjustment factor of the product data type
1
(default) | floating-point number greater than or equal to 1 and less than 2
Slope adjustment factor of the product data type, specified as a floating-point number greater than or equal to 1 and less than 2.
Note
Changing one of these properties affects the others.
ProductWordLength
— Word length of the product data type in bits
32
(default) | positive integer
Word length of the product data type in bits, specified as a positive integer.
Rounding and Overflow Properties
OverflowAction
— Action to take on overflow
Saturate
(default) | Wrap
Action to take on overflow, specified as one of these values:
Saturate
— Saturate to maximum or minimum value of the fixed-point range on overflow.Wrap
— Wrap on overflow. This mode is also known as two's complement overflow.
RoundingMethod
— Rounding method to use
Nearest
(default) | Ceiling
| Convergent
| Zero
| Floor
| Round
Rounding method to use, specified as one of the following:
Nearest
— Round toward nearest. Ties round toward positive infinity.Ceiling
— Round toward positive infinity.Convergent
— Round toward nearest. Ties round to the nearest even stored integer (least biased).Zero
— Round toward zero.Floor
— Round toward negative infinity.Round
— Round toward nearest. Ties round toward negative infinity for negative numbers, and toward positive infinity for positive numbers.
Version History
Introduced before R2006a
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