关于sensor中的sign和map，求指点
时间：10-02
整理：3721RD
点击：
/*
* @sign, map: only used in acceleROMeter/magnetic field
* sometimes, the sensor output need to be remapped before reporting to php?mod=tag&id=6090" target="_blank" class="relatedlink">Framework.
* the 'sign' is only -1 or +1 to align the sign for framework's coordinate system
* the 'map' align the value for framework's coordinate system. Take accelerometer
* as an exmaple:
* assume HAL receives original acceleration: acc[] = {100, 0, 100}
* sign[] = {1, -1, 1, 0};
* map[] = {HWM_CODE_ACC_Y, HWM_CODE_ACC_X, HWM_CODE_ACC_Z, 0};
* according to the above 'sign' & 'map', the sensor output need to remap as {y, -x, z}:
* float resolution = unit_numerator*GRAVITY_EARTH/unit_denominator;
* acc_x = sign[0]*acc[map[0]]*resolution;
* acc_y = sign[1]*acc[map[1]]*resolution;
* acc_z = sign[2]*acc[map[2]]*resolution;
*/
这段注解一直看的懵懵懂懂的，求高手指点一下，这里的sign和map到底是个怎样的概念?
* @sign, map: only used in acceleROMeter/magnetic field
* sometimes, the sensor output need to be remapped before reporting to php?mod=tag&id=6090" target="_blank" class="relatedlink">Framework.
* the 'sign' is only -1 or +1 to align the sign for framework's coordinate system
* the 'map' align the value for framework's coordinate system. Take accelerometer
* as an exmaple:
* assume HAL receives original acceleration: acc[] = {100, 0, 100}
* sign[] = {1, -1, 1, 0};
* map[] = {HWM_CODE_ACC_Y, HWM_CODE_ACC_X, HWM_CODE_ACC_Z, 0};
* according to the above 'sign' & 'map', the sensor output need to remap as {y, -x, z}:
* float resolution = unit_numerator*GRAVITY_EARTH/unit_denominator;
* acc_x = sign[0]*acc[map[0]]*resolution;
* acc_y = sign[1]*acc[map[1]]*resolution;
* acc_z = sign[2]*acc[map[2]]*resolution;
*/
这段注解一直看的懵懵懂懂的，求高手指点一下，这里的sign和map到底是个怎样的概念?