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#ifndef WMM_H
#define WMM_H
#include <stdint.h>
#define WMM_EPOCH 2020.0f
typedef struct{ float gnm; float hnm; float dgnm; float dhnm;} wmm_cof_record_t;
/**
* Initialize the WMM. Needs calling only once. */void wmm_init(void);
/**
* Get the date in WMM format * * @param year Year in 2 digit format of 21st centuary, i.e. 20 represents 2020 * @param month Month, 1 to 12 * @param date Date of month, 1 to 31 * @return Date in WMM format * @note No checking of illegal dates is done */float wmm_get_date(uint8_t year, uint8_t month, uint8_t date);
/**
* Get the magnetic variation at a point on the earth's surface * * @param glat Latitude in degrees and fractional degrees, negative west * @param glon Longitude in degrees and fractional degrees, negative west * @param time_years The date as returned from wmm_get_date * @param dec Pointer to float holding calculated magnetic variation (also known as declination). Negative is west. * @note The altitude used is the ellipsoid at the supplied latitude/longitude, not the earth's surface. This will * give very small errors in some parts of the world comapred to sea level. */void E0000(float glat, float glon, float time_years, float *dec);
#endif
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