2014/10/15 下午 10:03:51

iphone Programming Glossary: approximation

how can i trace the finger movement on touch for drawing smooth curves?

http://stackoverflow.com/questions/1052119/how-can-i-trace-the-finger-movement-on-touch-for-drawing-smooth-curves

Rom splines . Fit a curve to your samples A more advance and more difficult approach would be to do a Least Squares approximation to your sample points. If you want try this the procedure looks something like the following Collect sample points Define..

MKMapView Zoom and Region

http://stackoverflow.com/questions/1166444/mkmapview-zoom-and-region

3 So you can specify zoom levels around a center point by using an appropriately sized MKCoordinateSpan. As an approximation of Google's numeric zoom levels you could reverse engineer the span sizes that Google uses for a given zoom level and create..

How do I get the next and earlier date of the current date in iPhone sdk

http://stackoverflow.com/questions/1172698/how-do-i-get-the-next-and-earlier-date-of-the-current-date-in-iphone-sdk

Of course that is approximate unless you deal with all the gregorian calendar issues but if you just want a quick approximation NSDate earlierDate date addTimeInterval 1.0 24 60 60 That doesn't work with leap seconds etc but for most uses it is probably..

Weird Switch error in Obj-C

http://stackoverflow.com/questions/1180550/weird-switch-error-in-obj-c

on the subject to find out either way. 1 This is not meant to be a technically accurate description but a reasonable approximation for those not familiar with the issues involved. EDIT The solution I gave works in most cases cases being usages not switch..

Levenshtein Distance Algorithm better than O(n*m)?

http://stackoverflow.com/questions/4057513/levenshtein-distance-algorithm-better-than-onm

two rows of the matrix in memory so that will be order n . If you can afford to approximate there are poly logarithmic approximations. For the O n d^2 algorithm look for Ukkonen's optimization or its enhancement Enhanced Ukkonen . The best approximation..

Figure out time by latitude/longitude?

http://stackoverflow.com/questions/4632100/figure-out-time-by-latitude-longitude

improve this question Unfortunately timezones and time in general is never as simple as you would like. For a simple approximation you can follow jer's suggestion. Longitude ranges from 180 to 180 degrees there are 24 hours in a day so you get 15 degrees..

Convert decimal to fraction in Objective-C?

http://stackoverflow.com/questions/5552537/convert-decimal-to-fraction-in-objective-c

function wrapper of said algorithm typedef struct long nominator long denominator double error Fraction Find rational approximation to given real number David Eppstein UC Irvine 8 Aug 1993 With corrections from Arno Formella May 2008 Function wrapper by.. is the maximum denominator allowed based on the theory of continued fractions if x a1 1 a2 1 a3 1 a4 ... then best approximation is found by truncating this series with some adjustments in the last term . Note the fraction can be recovered as the first..

CoreAudio AudioTimeStamp.mHostTime clock frequency?

http://stackoverflow.com/questions/675626/coreaudio-audiotimestamp-mhosttime-clock-frequency

system clock. First of all the system clock does not start at zero when the system is booted but at the system's best approximation of the current wall clock time . The normal system clock also is not running strictly upwards e.g. the system clock might..

Help calculating X and Y from Latitude and Longitude in iPhone

http://stackoverflow.com/questions/6852195/help-calculating-x-and-y-from-latitude-and-longitude-in-iphone

angle. iphone google maps geolocation overlay share improve this question I would do this by assuming flat earth approximation and use vector algebra to relate angles and distances in the lat lon space to the x y pixel space. For example I am assuming..

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

curves addObject self createSmallArc radius_ a1 a1 a2 a2 totalAngle fabsf a2 a1 a1 a2 return curves Cubic bezier approximation of a circular arc centered at the origin This algorithm is based on the approach described in A. Ri禳kus Approximation of.. ctrlPoint2.y NSNumber numberWithFloat r cosf a2 endPoint.x NSNumber numberWithFloat r sinf a2 endPoint.y nil Bezier approximation example @note adapted for xCode by Valentine Konov valentine @konov.su 2013 @param inSprite_ is sprite angle_ signed angle..

Overlay Color Blend in OpenGL ES / iOS / Cocos2d

http://stackoverflow.com/questions/8771413/overlay-color-blend-in-opengl-es-ios-cocos2d

glEnableClientState GL_TEXTURE_COORD_ARRAY glEnable GL_TEXTURE_2D And here some results As you can see is a good approximation but this two images has error OpenGL error 0x0502 in EAGLView swapBuffers My Questions are How can I remove or fix this..