Question

I am trying to get the rate per minute that someone is pushing a button on iOS.When they press the button, a label is updated with the presses per minute. I have the code mostly working, but it is spitting out large positive/large negative numbers for the rate. I think it is in my math for computing the average. Any help would be appreciated and if you need any more information please let me know!

- (IBAction)countStroke:(id)sender {
    double avg;
    double start = [[NSDate date] timeIntervalSince1970];


    if(start - endStroke > 60){
        count = 0;
    }

    if(count == 0){
        NSString *firststroke = [[NSString alloc] initWithFormat:@"First Stroke"];
        self.label.text = firststroke;
        endStroke = [[NSDate date] timeIntervalSince1970];
        count ++;

    }
    else {
    endStroke = [[NSDate date] timeIntervalSince1970];
    avg = ((60000 * count)/(endStroke - start));
    NSString *rate = [NSString stringWithFormat:@"%d", avg];
    self.label.text = rate;

    }
}

Answer 1

%d is used for integer values. Use %f instead