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Code Issues Releases Activity

Store 180 deg in flash now and even make the flash and ram version share a

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lookup method.  Still don't get the same results.
This commit is contained in:
James Cotton 2012-08-03 12:31:15 -05:00
parent 9f3c8dddd3
commit f3dc2dc2ad
1 changed files with 28 additions and 38 deletions
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66
flight/Libraries/math/sin_lookup.c
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@ -33,6 +33,7 @@
#include "stdbool.h"
#include "stdint.h"
//#define FLASH_TABLE
#ifdef FLASH_TABLE
/** Version of the code which precomputes the lookup table in flash **/
@ -46,7 +47,16 @@
0.766044f,0.777146f,0.788011f,0.798636f,0.809017f,0.819152f,0.829038f,0.838671f,0.848048f,0.857167f,
0.866025f,0.874620f,0.882948f,0.891007f,0.898794f,0.906308f,0.913545f,0.920505f,0.927184f,0.933580f,
0.939693f,0.945519f,0.951057f,0.956305f,0.961262f,0.965926f,0.970296f,0.974370f,0.978148f,0.981627f,
0.984808f,0.987688f,0.990268f,0.992546f,0.994522f,0.996195f,0.997564f,0.998630f,0.999391f,0.999848f
0.984808f,0.987688f,0.990268f,0.992546f,0.994522f,0.996195f,0.997564f,0.998630f,0.999391f,0.999848f,
1.000000f,0.999848f,0.999391f,0.998630f,0.997564f,0.996195f,0.994522f,0.992546f,0.990268f,0.987688f,
0.984808f,0.981627f,0.978148f,0.974370f,0.970296f,0.965926f,0.961262f,0.956305f,0.951057f,0.945519f,
0.939693f,0.933580f,0.927184f,0.920505f,0.913545f,0.906308f,0.898794f,0.891007f,0.882948f,0.874620f,
0.866025f,0.857167f,0.848048f,0.838671f,0.829038f,0.819152f,0.809017f,0.798636f,0.788011f,0.777146f,
0.766044f,0.754710f,0.743145f,0.731354f,0.719340f,0.707107f,0.694658f,0.681998f,0.669131f,0.656059f,
0.642788f,0.629320f,0.615661f,0.601815f,0.587785f,0.573576f,0.559193f,0.544639f,0.529919f,0.515038f,
0.500000f,0.484810f,0.469472f,0.453990f,0.438371f,0.422618f,0.406737f,0.390731f,0.374607f,0.358368f,
0.342020f,0.325568f,0.309017f,0.292372f,0.275637f,0.258819f,0.241922f,0.224951f,0.207912f,0.190809f,
0.173648f,0.156434f,0.139173f,0.121869f,0.104528f,0.087156f,0.069756f,0.052336f,0.034899f,0.017452f
};
int sin_lookup_initalize()
@ -54,28 +64,6 @@ int sin_lookup_initalize()
return 0;
}
/**
* Use the lookup table to return sine(angle) where angle is in radians
* to save flash this cheats and uses trig functions to only save
* 90 values
* @param[in] angle Angle in degrees
* @returns sin(angle)
*/
float sin_lookup_deg(float angle)
{
int i_ang = ((int32_t) angle) % 360;
if(i_ang > 270) // for 270 to 360 deg
return -sin_table[360 - i_ang];
else if (i_ang > 180) // for 180 to 270 deg
return -sin_table[i_ang - 180];
else if (i_ang > 90) // for 90 to 170 deg
return sin_table[180 - i_ang];
else // for 0 to 90 deg
return sin_table[i_ang];
return 0;
}
#else
/** Version of the code which allocates the lookup table in heap **/
@ -98,23 +86,25 @@ int sin_lookup_initalize()
return 0;
}
/**
* Uses the lookup table to calculate sine (angle is in degrees)
* @param[in] angle in degrees
* @returns sin(angle)
*/
float sin_lookup_deg(float angle) {
int i_ang = ((int32_t)angle) % 360;
if (i_ang > 180)
return - sin_table[i_ang-180];
else
return sin_table[i_ang];
}
#endif
/**
* Use the lookup table to return sine(angle) where angle is in radians
* to save flash this cheats and uses trig functions to only save
* 90 values
* @param[in] angle Angle in degrees
* @returns sin(angle)
*/
float sin_lookup_deg(float angle)
{
int i_ang = ((int32_t) angle) % 360;
if (i_ang > 180) // for 180 to 270 deg
return -sin_table[i_ang - 180];
else // for 0 to 90 deg
return sin_table[i_ang];
return 0;
}
/**
* Get cos(angle) using the sine lookup table