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2014/10/15 ¤U¤È 10:14:43

iphone Programming Glossary: tan

obtaining the rotation and size of a UIImageView based on its transformation matrices

http://stackoverflow.com/questions/1379811/obtaining-the-rotation-and-size-of-a-uiimageview-based-on-its-transformation-mat

and size of a UIImageView based on its transformation matrices If I have the original transform matrix of a rectangular UIImageView and this image is scaled and rotated and by the end I can read the final transform matrix of this same.. axis looks like this ¡Sx 0 Sy A matrix to rotate clockwise by R radians looks like this ¡cos R sin R sin R cos R Using standard matrix multiplication the combined scaling and rotation matrix will look like this ¡Sx.cos R Sx.sin R Sy.sin R Sy.cos.. £c d Now we want to extract from this matrix the values of Sx Sy and R. We can use a simple trigonometric identity here tan A sin A cos A We can use this with the first row of the matrix to conclude that tan R Sx.sin R Sx.cos R b a and therefore..

NSString to equation

http://stackoverflow.com/questions/1501949/nsstring-to-equation

you to do variable substitutions 3x 42 evaluate with x 7 . It even has support for mathematical functions like sin cos tan their inverses dtor log .... edit a long time later... While GCMathParser is pretty awesome it has the flaw of not being..

OpenGL ES (iPhone) Touch Picking

http://stackoverflow.com/questions/2231433/opengl-es-iphone-touch-picking

1 float fov 45.0f M_PI 180.0f float near 0.01 far 10.0f float aspect float backingWidth float backingHeight float top tan fov near float bottom top float left aspect bottom float right aspect top I'm a viewing volume symmetric projection matrix..

Calculate angle for rotation in Pie Chart

http://stackoverflow.com/questions/5102942/calculate-angle-for-rotation-in-pie-chart

gestureMovedPoint CGFloat previousAngle self angleBetweenPoints gestureStartPoint second11 gestureMovedPoint atan2 gestureMovedPoint.y gestureStartPoint.y gestureMovedPoint.x gestureStartPoint.x 180 M_PI CGFloat currentAngle atan2 self.transform.b.. atan2 gestureMovedPoint.y gestureStartPoint.y gestureMovedPoint.x gestureStartPoint.x 180 M_PI CGFloat currentAngle atan2 self.transform.b self.transform.a atan2 gestureMovedPoint.y gestureStartPoint.y gestureMovedPoint.x gestureStartPoint.x.. gestureMovedPoint.x gestureStartPoint.x 180 M_PI CGFloat currentAngle atan2 self.transform.b self.transform.a atan2 gestureMovedPoint.y gestureStartPoint.y gestureMovedPoint.x gestureStartPoint.x 180 M_PI CGFloat angleToRotate currentAngle..

Rotate a Sprite on a bezier path with touch - Cocos2D/Box2D

http://stackoverflow.com/questions/7494795/rotate-a-sprite-on-a-bezier-path-with-touch-cocos2d-box2d

X axis float a a2 a1 2.0 float x4 r cosf a float y4 r sinf a float x1 x4 float y1 y4 float k 0.5522847498 float f k tan a float x2 x1 f y4 float y2 y1 f x4 float x3 x2 float y3 y2 Find the arc points actual locations by computing x1 y1 and..