Accelerate.frameworkを用いた平均値計算

TTMArithmetic.m

//
//  TTMArithmetic.m
//
//  Copyright (c) 2015 Shuichi Tsutsumi. All rights reserved.
//

#import "TTMArithmetic.h"
@import Accelerate;


@implementation MOSArithmetic

- (double)mean:(NSArray *)values {
    
    double x[[values count]];
    for (int i=0; i<[values count]; i++) {
        x[i] = [values[i] doubleValue];
    }
    
    double result = 0.0;
    vDSP_meanvD(x, 1, &result, (vDSP_Length)[values count]);
    
    return result;
}

- (float)meanf:(NSArray *)values {
    
    float x[[values count]];
    for (int i=0; i<[values count]; i++) {
        x[i] = [values[i] floatValue];
    }

    float result = 0.0;
    vDSP_meanv(x, 1, &result, (vDSP_Length)[values count]);
    
    return result;
}

@end