# Formula for CGPointApplyAffineTransform function in iOS

I am trying to affine rotate matrix in Android based on iOS Code

iOS has two functions CGAffineTransformMakeRotation and CGPointApplyAffineTransform used for calculation

```Step 1: CGAffineTransformMakeRotation();

Input:

2.2860321998596191

Result:
a = -0.65579550461444569,
b = 0.75493857771840255,
c = -0.75493857771840255,
d = -0.65579550461444569,
tx = 0, ty = 0

Formula:

```

I am able to calculate a,b,c,d for step 1 using above formula

```Step 2: CGPointApplyAffineTransform()

Input :

x = 612.55191924649432,
y = -391.95960729287646
And Matrix return from Step 1

Result:
x = -105.80336653205421,
y = 719.48442314773808
```

Does anyone know the formula used in ApplyAffineTransform?

# I need help for Step 2

I have tried with Android's Matrix class - Not Working

I have also tried with Java's AffineTransform - Not working

The math behind the CGAffineTransform functions is described in “The Math Behind the Matrices” in the Quartz 2D Programming Guide.

The formulae for transforming a point using an affine transform are given as:

x' = ax + cy + tx y' = bx + dy + ty

Incidentally, in your step 1, you have reversed the signs of b and c, which has the effect of reversing the direction of rotation.