Operator Library: Arithmetics
Implemented Function ist not arccos(x) | |
---|---|
The implemented function is -1 * arccos(x). See description. |
The operator ARCCOS is calculating the arc cosine of the input. Note that not arccos(x) is implemented. Instead, the result is inverted i.e. -1 * arccos(x) is implemented.
The input range of arccos is [-1,1]. The operator maps the input interval range [-1, 1] to
where
is the bit width at the input. As can be seen, not the full value range of the input is used. If an input value is outside the allowed value range, the operator will clip the value to -1 or 1. Thus, the argument x of the arccos is determined by
The operator calculates the inverse of the arccos i.e. the output value range is not [0, - π] it is [- π, 0]. The output value range of the operator in VisualApplets is mapped to
where
is the bit width at the output link. Thus the output value is
The following image shows the plot of the normal inverse arccos function.
In the next figure, the VisualApplets operator implementation is shown. Note the input and output bit widths.
Link Parameter | Input Link I | Output Link O |
---|---|---|
Bit Width | [8, 12] | [8,32] |
Arithmetic | signed | signed |
Parallelism | any | as I |
Kernel Columns | 1 | as I |
Kernel Rows | 1 | as I |
Img Protocol | {VALT_IMAGE2D, VALT_LINE1D, VALT_PIXEL0D} | as I |
Color Format | VAF_GRAY | as I |
Color Flavor | FL_NONE | as I |
Max. Img Width | any | as I |
Max. Img Height | any | as I |
The use of operator ARCCOS is shown in the following examples:
-
'Functional Example for Specific Operators of Library Arithmentics: Trigonometric Functions'
Examples - Demonstration of how to use the operator