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  1. PO
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    <p>In <code>drawMapRect</code>, this line is probably the cause of the point rects not showing:</p> <pre><code>CGRect rect = CGRectMake(datpoint.x/zoomScale, datpoint.y/zoomScale, 1.0/zoomScale, 1.0/zoomScale); </code></pre> <p>You probably do not want to change the position of the point's rect based on the zoomScale.<br> The rect's <em>apparent</em> position based on the zoom will be done automatically by the map view. </p> <p>The current code is changing its <em>absolute</em> position and size on the map based on the zoom.<br> The resulting position is most likely not on the map.</p> <p>Instead, draw the point's rect without any scaling. </p> <p>However, to calculate the right width to use in CGPoints (from meters), you need to do some calculation:</p> <pre><code>for (NSValue *point in self.points) { MKMapPoint mapPoint; [point getValue:&amp;mapPoint]; CGPoint datpoint = [self pointForMapPoint:mapPoint]; CLLocationDistance rectWidthMeters = 100000.0; //above sets rect width to 100 km, adjust as needed CLLocationCoordinate2D mpc = MKCoordinateForMapPoint(mapPoint); double rectWidthMapPoints = MKMapPointsPerMeterAtLatitude(mpc.latitude); MKMapPoint mpRight = MKMapPointMake (mapPoint.x + (rectWidthMapPoints * rectWidthMeters), mapPoint.y); CGPoint datpointRight = [self pointForMapPoint:mpRight]; CGFloat rectWidth = datpointRight.x - datpoint.x; CGRect rect = CGRectMake(datpoint.x, datpoint.y, rectWidth, rectWidth); CGContextFillRect(context, rect); } </code></pre> <p>Make sure you are zoomed in enough at the right location to see the squares.</p> <p><br> You may be interested in looking at <a href="https://developer.apple.com/library/ios/samplecode/HazardMap/Introduction/Intro.html" rel="nofollow">Apple's sample app HazardMap</a> which demonstrates something similar showing color-coded earthquake hazard levels based on a grid of locations.</p>
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    1. POiOS 7 - Drawing a set of coords on MapKit with MKOverlayRenderer
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    1. COI have tried it without scaling by zoomScale as well and still nothing shows. However, when I add your code I see a big red blob over the correct area. Probably because of the density of the points in my data. Why is it that I can't just set the size of the points to 1x1 or something?
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    2. COThe example uses a rect width of 100 _kilometers_ (~ 62 _miles_). You'll need to adjust it based on the density of your points (eg. try 100 meters instead of 100000). You _can_ set it to a constant of 1 CGPoint but it would be very hard to see even at the highest zoom. Using a fixed real-world distance as the width might be simpler to manage (the data points are based on real-world coordinates).
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