From 76177aa280494bb36d7a0bcbda1078d4db717020 Mon Sep 17 00:00:00 2001 From: Ali Labbene Date: Mon, 9 Dec 2019 11:25:19 +0100 Subject: Official ARM version: v4.5 --- Documentation/DSP/html/group__cos.html | 236 +++++++++++++++++++++++++++++++++ 1 file changed, 236 insertions(+) create mode 100644 Documentation/DSP/html/group__cos.html (limited to 'Documentation/DSP/html/group__cos.html') diff --git a/Documentation/DSP/html/group__cos.html b/Documentation/DSP/html/group__cos.html new file mode 100644 index 0000000..3a14513 --- /dev/null +++ b/Documentation/DSP/html/group__cos.html @@ -0,0 +1,236 @@ + + + + + +Cosine +CMSIS-DSP: Cosine + + + + + + + + + + + + + + + +
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CMSIS-DSP +  Version 1.4.7 +
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CMSIS DSP Software Library
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+Functions
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Cosine
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Fast Math Functions
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+Functions

float32_t arm_cos_f32 (float32_t x)
 Fast approximation to the trigonometric cosine function for floating-point data.
 
q15_t arm_cos_q15 (q15_t x)
 Fast approximation to the trigonometric cosine function for Q15 data.
 
q31_t arm_cos_q31 (q31_t x)
 Fast approximation to the trigonometric cosine function for Q31 data.
 
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Description

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Computes the trigonometric cosine function using a combination of table lookup and linear interpolation. There are separate functions for Q15, Q31, and floating-point data types. The input to the floating-point version is in radians while the fixed-point Q15 and Q31 have a scaled input with the range [0 +0.9999] mapping to [0 2*pi). The fixed-point range is chosen so that a value of 2*pi wraps around to 0.

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The implementation is based on table lookup using 256 values together with linear interpolation. The steps used are:

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  1. Calculation of the nearest integer table index
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  2. Compute the fractional portion (fract) of the table index.
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  3. The final result equals (1.0f-fract)*a + fract*b;
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where

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Function Documentation

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float32_t arm_cos_f32 (float32_t x)
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Parameters
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[in]xinput value in radians.
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Returns
cos(x).
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Examples:
arm_sin_cos_example_f32.c.
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References FAST_MATH_TABLE_SIZE, and sinTable_f32.

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Referenced by main().

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q15_t arm_cos_q15 (q15_t x)
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Parameters
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[in]xScaled input value in radians.
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Returns
cos(x).
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The Q15 input value is in the range [0 +0.9999] and is mapped to a radian value in the range [0 2*pi).

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References FAST_MATH_Q15_SHIFT, and sinTable_q15.

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q31_t arm_cos_q31 (q31_t x)
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Parameters
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[in]xScaled input value in radians.
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Returns
cos(x).
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The Q31 input value is in the range [0 +0.9999] and is mapped to a radian value in the range [0 2*pi).

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References FAST_MATH_Q31_SHIFT, and sinTable_q31.

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+ + + + -- cgit