I am trying to to call MKPolylines' + polylineWithCoordinates:count: method.
How can I create a CLLocationCoordinate2D * object in this case. I have gone through this particular answer in CLLocationCoordinate2D without knowing how many will be in the array?
// unpacking an array of NSValues into memory
CLLocationCoordinate2D *points = malloc([mutablePoints count] * sizeof(CLLocationCoordinate2D));
for(int i = 0; i < [mutablePoints count]; i++) {
[[mutablePoints objectAtIndex:i] getValue:(points + i)];
}
MKPolyline *myPolyline = [MKPolyline polylineWithCoordinates:points count:[mutablePoints count]];
free(points);
What kind of entries are in the array mutablePoints in the above case?
If your question is simply what kind of entries are in the array, the answer is quite simple: NSValue entries. You can have a look at this guide for more info on how to use NSValues.
CLLocationCoordinate2D coordinate;
for (int i = 0; i < arr.count; i++)
{
float t1 = [[arr objectAtIndex:1] floatValue];
float t2 = [[arr objectAtIndex:0] floatValue];
coordinate.latitude = t1;
coordinate.longitude = t2;
}
Related
I want to sort a NSMutableArray, where each row is a NSMutableDictionary, with my GPS position from CoreLocation framework.
This is an example of my array of POI
arrayCampi = (
{
cap = 28100;
"cell_phone" = "";
championship = "IBL 1D";
citta = Novara;
division = "";
email = "";
fax = 0321457933;
indirizzo = "Via Patti, 14";
latitude = "45.437174";
league = "";
longitude = "8.596029";
name = "Comunale M. Provini";
naz = Italy;
prov = NO;
reg = Piemonte;
sport = B;
surname = "Elettra Energia Novara 2000";
telefono = 03211816389;
webaddress = "http://www.novarabaseball.it/";
})
I need to sort this array with my location (lat and long) with field 'latitude' and 'longitude' of each row in ascending mode (first row is POI nearest to me).
I have tried this solution without success:
+ (NSMutableArray *)sortBallparkList:(NSMutableArray *)arrayCampi location:(CLLocation *)myLocation {
if ([arrayCampi count] == 0) {
return arrayCampi;
}
if (myLocation.coordinate.latitude == 0.00 &&
myLocation.coordinate.longitude == 0.00) {
return arrayCampi;
}
NSMutableArray *sortedArray = [NSMutableArray arrayWithArray:arrayCampi];
BOOL finito = FALSE;
NSDictionary *riga1, *riga2;
while (!finito) {
for (int i = 0; i < [sortedArray count] - 1; i++) {
finito = TRUE;
riga1 = [sortedArray objectAtIndex: i];
riga2 = [sortedArray objectAtIndex: i+1];
CLLocationDistance distanceA = [myLocation distanceFromLocation:
[[CLLocation alloc]initWithLatitude:[[riga1 valueForKey:#"latitude"] doubleValue]
longitude:[[riga1 valueForKey:#"longitude"] doubleValue]]];
CLLocationDistance distanceB = [myLocation distanceFromLocation:
[[CLLocation alloc]initWithLatitude:[[riga2 valueForKey:#"latitude"] doubleValue]
longitude:[[riga2 valueForKey:#"longitude"] doubleValue]]];
if (distanceA > distanceB) {
[riga1 retain];
[riga2 retain];
[sortedArray replaceObjectAtIndex:i+1 withObject:riga2];
[sortedArray replaceObjectAtIndex:i withObject:riga1];
[riga1 release];
[riga2 release];
finito = FALSE;
}
}
}
return sortedArray;
}
Can anyone help me, also with other solution?
Alex.
Sorting by lat and long will not give you the nearest location from any given coordinates. As an approximation*) you could use Pythagoras (you learned that in high school, remember?):
float distance = sqrtf(powf((origLat-destLat),2)+powf((origLon-destLon), 2));
Simply add that to your dictionary with key #"distance" and sort with
NSArray *sorted = [arrayOfDictionaries sortedArrayUsingDescriptors:
#[[NSSortDescriptor sortDescriptorWithKey:#"distance" ascending:YES]]];
*) It's an approximation because theoretically distance between two points is a curved line on the surface of an ellipsoid.
[arrayCampi sortedArrayUsingSelector:#selector(compare:)];
- (NSComparisonResult)compare:(NSDictionary *)otherObject {
if ([[self objectForKey:#"key"] isEqual:[otherObject objectForKey:#"key"]]) {
return NSOrderedSame;
}
else if (//condition) {
return NSOrderedAscending;
}
else {
return NSOrderedDescending;
}
}
Take a look at How to sort an NSMutableArray with custom objects in it?
I think there's no need to implement your own sorting algorithm. There are the ready ones out there :-) I would suggest to look at NSSortDescriptor.
And since you keep your geo coordinates in NSString format, and not the NSNumber, you probably would need to write your own NSPredicate for NSString objects comparison in your class. (I don't remember if #"123" is greater than #"1.23", I mean special symbol '.')
I have been working on an iPhone app, where-in i have list of users in a NSMutableArray like below.
myMutableArray: (
{
FirstName = Getsy;
LastName = marie;
Latitude = "30.237314";
Longitude = "-92.461008";
},
{
FirstName = Angel;
LastName = openza;
Latitude = "30.260329";
Longitude = "-92.450414";
},
{
FirstName = Sara;
LastName = Hetzel;
Latitude = "30.2584499";
Longitude = "-92.4135357";
}
)
I need to sort users based on the location who is nearby to my location by calculating latitude and longitude. I am not able to achieve this till now. Could someone help me on giving some samples?
UPDATED: I am trying like below as per Mr.sch suggested. Please check my updated code. Is it fine?.
NSArray *orderedUsers = [myMutableArray sortedArrayUsingComparator:^(id a,id b) {
NSArray *userA = (NSArray *)a;
NSArray *userB = (NSArray *)b;
CGFloat aLatitude = [[userA valueForKey:#"Latitude"] floatValue];
CGFloat aLongitude = [[userA valueForKey:#"Longitude"] floatValue];
CLLocation *participantALocation = [[CLLocation alloc] initWithLatitude:aLatitude longitude:aLongitude];
CGFloat bLatitude = [[userA valueForKey:#"Latitude"] floatValue];
CGFloat bLongitude = [[userA valueForKey:#"Longitude"] floatValue];
CLLocation *participantBLocation = [[CLLocation alloc] initWithLatitude:bLatitude longitude:bLongitude];
CLLocation *myLocation = [[CLLocation alloc] initWithLatitude:locationCoordinates.latitude longitude:locationCoordinates.longitude];
CLLocationDistance distanceA = [participantALocation distanceFromLocation:myLocation];
CLLocationDistance distanceB = [participantBLocation distanceFromLocation:myLocation];
if (distanceA < distanceB) {
return NSOrderedAscending;
} else if (distanceA > distanceB) {
return NSOrderedDescending;
} else {
return NSOrderedSame;
}
}];
Thank you!
NSArray *orderedUsers = [users sortedArrayUsingComparator:^(id a,id b) {
User *userA = (User *)a;
User *userB = (User *)b;
CLLocationDistance distanceA = [userA.location getDistanceFromLocation:myLocation];
CLLocationDistance distanceB = [userB.location getDistanceFromLocation:myLocation];
if (distanceA < distanceB) {
return NSOrderedAscending
} else if (distanceA > distanceB) {
return NSOrderedDescending;
} else {
return NSOrderedSame;
}
}];
First thing, you will need to calculate the distance between your current location and the location of each other user.
Talking mathematically, here is a Wolfram|Alpha example
Now "programmatic-ally", you can use CLLocation class, here is an example:
(CLLocationDistance)getDistanceFrom:(const CLLocation *)location
But first you will need to create the location object from your Latitude and Longitude. You can use:
(id)initWithLatitude:(CLLocationDegrees)latitude longitude:(CLLocationDegrees)longitude
You can calculate the distance (geographical, not flat plane!) between your position and each of these items' positions and order by that value.
- (void)viewDidLoad {
[super viewDidLoad];
// This Array Taken Globally
List_of_locationsArray =[[NSMutableArray alloc]initWithObjects:
#{#"latitude" : #"17.415045",#"logitude":#"78.421424"} ,#{#"latitude" : #"17.415045",#"logitude":#"78.421424"},#{#"latitude" : #"17.415045",#"logitude":#"78.421424"},#{#"latitude" : #"17.415045",#"logitude":#"78.421424"},#{#"latitude" : #"17.415045",#"logitude":#"78.421424"}
,nil];
}
-(void)sortingLocationsArray{
// CLLocation* currentLocation =[[CLLocation alloc]initWithLatitude:[currentLatitude doubleValue] longitude:[currentLogitude doubleValue]];
CLLocation* currentLocation =[[CLLocation alloc]initWithLatitude: currentLatitudeHere longitude:CurrentLogHere];
NSMutableArray* tempLocationsArr = [[NSMutableArray alloc]initWithCapacity:[locationsArray count]];
for (int i=0; i<[locationsArray count]; i++) {
CLLocationDegrees latValue = [[locationsArray[i] objectForKey:#"latitude"] doubleValue];
CLLocationDegrees longValue = [[locationsArray[i] objectForKey:#"logitude"] doubleValue];
CLLocation* location = [[CLLocation alloc]initWithLatitude:latValue longitude:longValue];
[tempLocationsArr addObject:location];
NSArray* sortLocationArry = [tempLocationsArr sortedArrayUsingComparator:^NSComparisonResult(CLLocation* location1, CLLocation* location2) {
CLLocationDistance distA = [location1 distanceFromLocation:currentLocation];
CLLocationDistance distB = [location2 distanceFromLocation:currentLocation];
if (distA < distB) {
return NSOrderedAscending;
} else if ( distA > distB) {
return NSOrderedDescending;
} else {
return NSOrderedSame;
}
}];
//ArrayAfterSorting is another mutable Array to Store Sorting Data
[ArrayAfterSorting removeAllObjects];
[sortLocationArry enumerateObjectsUsingBlock:^(CLLocation* location, NSUInteger idx, BOOL *stop) {
NSMutableDictionary *tempDict = [[NSMutableDictionary alloc]init];
[tempDict setObject:[NSString stringWithFormat:#"%f",location.coordinate.latitude] forKey:#"latitude"];
[tempDict setObject:[NSString stringWithFormat:#"%f",location.coordinate.longitude] forKey:#"logitude"];
[ArrayAfterSorting addObject:tempDict];
}];
NSLog(#"sortedArray : %#", ArrayAfterSorting);
}
}
You may solve your problem in following way
1)Firstly store all above values in separate array Like latArray ,longArray,nameArray
2)Now get the distance between location(longArray,latArray) from your current location.
Then store these distances in separate Array(distanceArray).
//getDistance Between currentLocation and desired Location
-(void *)getDistanceFromCurrentLocation{
for(int val=0;val<[latArray count];val++){
NSString *dis_From_Current_Location;
dis_From_Current_Location =nil;
CGFloat str_Longitude=[[defaults objectForKey:#"long"]floatValue];
CGFloat str_Latitude=[[defaults objectForKey:#"lati"]floatValue];
//Suppose this is your current location
CGFloat lat1= [[latArray objectAtIndex:val]floatValue];
//these array for lat
CGFloat long1=[[longArray objectAtIndex:val]floatValue];
//these array for longArray
CLLocation *location1 = [[CLLocation alloc] initWithLatitude:lat1 longitude:long1];
CLLocation *location2 = [[CLLocation alloc] initWithLatitude:str_Latitude longitude:str_Longitude];
CLLocationDistance dist=[location1 distanceFromLocation:location2];
NSLog(#"Distance i meters: %f", [location1 distanceFromLocation:location2]);
long long v = llabs(dist/1000);
dis_From_Current_Location=[NSString stringWithFormat:#"%lld km",v];
[location1 release];
[location2 release];
[distanceArray addObject: dis_From_Current_Location];
//distanceArray is Global NsMutableArray.
}
}
Now You should Apply sorting method(selection, bubble) fro sorting the distances.
One thing need to care is that when you sort the distanceArray
please adjust values of nameArray as according to the distanceArray
See Below code for sorting the distanceArray and adjust the nameArray's value.
-(void)getSoretdArray{
NSString * tempStr,*tempStr2;
for(int i=0;i<[distanceArray count]; i++){
for(int j=i+1;j<[distanceArray count]; j++){
if([distanceArray objectAtIndex:j]>[distanceArray objectAtIndex:j+1]){
tempStr=[distanceArray objectAtIndex:j];
NSString* str= [distanceArray objectAtIndex:j+1];
[ distanceArray insertObject:str atIndex:j];
[distanceArray insertObject:tempStr atIndex:j+1] ;
//also change the name of corresponding location.
//you have to adjust the stored names in namArray for storing names of Corresponding Distances
tempStr2=[nameArray objectAtIndex:j];
NSString* str1= [nameArray objectAtIndex:j+1];
[ nameArray insertObject:str1 atIndex:j];
[nameArray insertObject:tempStr2 atIndex:j+1] ;
}
}
}
}
This will definitely work just try to use carefully
I'm trying to add Annotations to an array to place multiple pins on a map. I have everything in a for loop. The first time it loops through, it adds the object to the array just fine. When it goes back through... the array has 0 objects in it. Can anyone tell me why?
EDIT: I'm using ARC.
-(void)plotMultipleLocs {
float latitude;
float longitude;
NSRange commaIndex;
NSString *coordGroups;
for (int i=0; i<=cgIdArray.count; i++) {
coordGroups = [cgInAreaArray objectAtIndex:i];
commaIndex = [coordGroups rangeOfString:#","];
latitude = [[coordGroups substringToIndex:commaIndex.location] floatValue];
longitude = [[coordGroups substringFromIndex:commaIndex.location + 1] floatValue];
CLLocationCoordinate2D loc = CLLocationCoordinate2DMake(latitude, longitude);
MKCoordinateRegion reg = MKCoordinateRegionMakeWithDistance(loc, 1000, 1000);
self->mapView.region = reg;
MKPointAnnotation* ann = [[MKPointAnnotation alloc] init];
ann.coordinate = loc;
ann.title = [cgNameArray objectAtIndex:i];
ann.subtitle = [cgLocArray objectAtIndex:i];
NSMutableArray *mutAnnArray = [NSMutableArray arrayWithArray:annArray];
[mutAnnArray addObject:ann];
}
}
You are creating a mutable array within the loop and adding your object to it.
At the next iteration of the loop, you create a new mutable array and add a new annotation to it.
Leave aside the fact that you are creating it from another array rather than just adding your annotation to annArray
Basically, the array that you are adding objects to last as long as one iteration, and then goes out of scope.
Try moving the array out of the loop:
-(void)plotMultipleLocs {
float latitude;
float longitude;
NSRange commaIndex;
NSString *coordGroups;
NSMutableArray *mutAnnArray = [NSMutableArray arrayWithArray:annArray]; // Create one array outside the loop.
for (int i=0; i<=cgIdArray.count; i++) {
coordGroups = [cgInAreaArray objectAtIndex:i];
commaIndex = [coordGroups rangeOfString:#","];
latitude = [[coordGroups substringToIndex:commaIndex.location] floatValue];
longitude = [[coordGroups substringFromIndex:commaIndex.location + 1] floatValue];
CLLocationCoordinate2D loc = CLLocationCoordinate2DMake(latitude, longitude);
MKCoordinateRegion reg = MKCoordinateRegionMakeWithDistance(loc, 1000, 1000);
self->mapView.region = reg;
MKPointAnnotation* ann = [[MKPointAnnotation alloc] init];
ann.coordinate = loc;
ann.title = [cgNameArray objectAtIndex:i];
ann.subtitle = [cgLocArray objectAtIndex:i];
[mutAnnArray addObject:ann]; // Add the annotation to the single array.
}
// mutAnnArray will go out of scope here, so maybe return it, or assign it to a property
}
Have you tried retaining the instance to avoid it being released?
Every time through the loop, you create a new mutable array with the contents of a different array. The mutable array containing the object you added on the previous iteration is not kept.
I need to build an array using something like the following:
CLLocationCoordinate2D points[4];
points[0] = CLLocationCoordinate2DMake(41.000512, -109.050116);
points[1] = CLLocationCoordinate2DMake(41.002371, -102.052066);
points[2] = CLLocationCoordinate2DMake(36.993076, -102.041981);
points[3] = CLLocationCoordinate2DMake(36.99892, -109.045267);
Problem is, I will never know how many items are going to be in the array, so I can specify the count. Is there a way to create a CLLocationCoordinate2D array, and just insert new coordinates without knowing what the final total will be?
EDIT: My final goal is to use the coordinates to make an MKPolyline, using the polylineWithCoordinates method which needs a CLLocationCoordinate2D array.
// unpacking an array of NSValues into memory
CLLocationCoordinate2D *points = malloc([mutablePoints count] * sizeof(CLLocationCoordinate2D));
for(int i = 0; i < [mutablePoints count]; i++) {
[[mutablePoints objectAtIndex:i] getValue:(points + i)];
}
MKPolyline *myPolyline = [MKPolyline polylineWithCoordinates:points count:[mutablePoints count]];
free(points);
Box them up in an NSValue object and throw them in an NSMutableArray.
I want to get the maximum and minimum values of a NSMutableArray so I can create a core-plot plotspace and graph based around those max and min values.
My code is as follows:
NSMutableArray *contentArray = [NSMutableArray arrayWithCapacity:100];
NSUInteger i;
for (i=0; i<60; i++){
id x = [NSNumber numberWithFloat:i*0.05];
id y = [NSNumber numberWithFloat:1.2*rand()/(float)RAND_Max + 0.6];
[contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, #"x", y, #"y", nil]];
}
self.dataForPlot = contentArray;
CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat() length:CPDecimalFromFloat()];
plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat() length:CPDecimalFromFloat()];
What do I fill in the blanks for xRange and yRange assignment if I want the graph to span only the space of what's specified in contentArray?
In this case, you should use -[CPPlotSpace scaleToFitPlots:]. For more general calculations on array values, read on...
This is an ideal use for Key-Value coding and associated array operators. In your example,
float maxX = [[contentArray valueForKeyPath:#"#max.x"] floatValue];
float minY = [[contentArray valueForKeyPath:#"#min.x"] floatValue];
float maxY = [[contentArray valueForKeyPath:#"#max.y"] floatValue];
float minY = [[contentArray valueForKeyPath:#"#min.y"] floatValue];
The array operators call valueForKeyPath: on the contentArray which gives an array built by calling the same valueForKeyPath: on each member of the array with the key path to the right of the array operator (i.e. #min and #max). The orignal call then applies the given operator to the resulting array. You could easily define a category on NSArray to give you back a struct of min/max values:
typedef struct {
float minX;
float minY;
float maxX;
float maxY;
} ArrayValueSpace;
#implementation NSArray (PlotSpaceAdditions)
- (ArrayValueSpace)psa_arrayValueSpace {
ArrayValueSpace result;
result.maxX = [[contentArray valueForKeyPath:#"#max.x"] floatValue];
result.minX = [[contentArray valueForKeyPath:#"#min.x"] floatValue];
result.maxY = [[contentArray valueForKeyPath:#"#max.y"] floatValue];
result.minY = [[contentArray valueForKeyPath:#"#min.y"] floatValue];
return result;
}
You can find max and min values when you fill it, but it would work just when used in your snippet. If you want something more generic you should simply go through the list and searching for it.
// contentArray already defined
int maxX = 0, minX = 1000, maxY = 0, minY = 1000;
for (int i = 0; i < [contentArray count]; ++1)
{
int curX = [[[contentArray objectForKey:#"x"] objectAtIndex:i] integerValue];
int curY = [[[contentArray objectForKey:#"y"] objectAtIndex:i] integerValue];
if (curX < minX)
minX = curX;
else if (curX > maxX)
maxX = curX;
if (curY < minY)
minY = curY;
else if (curY > maxY)
maxY = curY;
}
You could use fast enumeration through the array.
.
NSUInteger maxX = 0;
NSUInteger minX = 0xFFFFFFFF; //(for 32 bit)
NSUInteger maxY = 0;
NSUInteger minY = 0xFFFFFFFF; //(for 32 bit)
for ( NSDictionary *dict in contentArray )
{
NSUInteger newX = [[dict objectForKey:#"x"] integerValue];
NSUInteger newY = [[dict objectForKey:#"y"] integerValue];
if (maxX > newX) maxX = newX;
if (minX > newX) minX = newX;
if (maxY > newY) maxY = newY;
if (minY > newY) minX = newY;
}
if you have NSMutableArray of NSDictionary objects you can use this:
-(float)findMax:array arrayKey:obj {
float max = [[[array objectAtIndex:0] objectForKey:obj] floatValue];
for ( NSDictionary *dict in array ) {
if(max<[[dict objectForKey:obj] floatValue])max=[[dict objectForKey:obj] floatValue];
}
return max;
}
-(float)findMin:array arrayKey:obj {
float min = [[[array objectAtIndex:0] objectForKey:obj] floatValue];
for ( NSDictionary *dict in array ) {
if (min > [[dict objectForKey:obj] floatValue])min = [[dict objectForKey:obj] floatValue];
}
return min;
}
You would access methods like this if in another class:
GraphData *c=[[GraphData alloc] init];
float maxY=[c findMax:plotData arrayKey:[NSNumber numberWithInt:1]]; //1 or 0 depending on axis
[c release];
//This gives Max and Min Value in NSMutableArrray
-(void)FindingMinAndMaxValueInNSMutableArray{
NSMutableArray *array=[[NSMutableArray alloc]initWithObjects:#"0.987",#"0.951",#"0.881",#"0.784",#"0.662",#"0.522",#"0.381",#"-0.265",#"-0.197", #"0.189",#"-0.233",#"0.310",#"0.402",#"0.402",#"0.988",#"0.633",#"0.661",#"0.656",#"0.617",#"0.634",#"0.690",#"0.767",#"0.836",nil];
NSLog(#"The Array Value is %#",array);
NSLog(#"The Array Count is %lu",(unsigned long)array.count);
NSNumber *maxValue = [array valueForKeyPath:#"#max.doubleValue"];
NSLog(#"The maxValue is %#",maxValue);
NSString *str=[NSString stringWithFormat:#"%#",maxValue];
NSInteger path=[array indexOfObject:str];
NSIndexPath *indexpath=[NSIndexPath indexPathForItem:path inSection:0];
NSLog(#"Max Value = %# and index = %ld",maxValue,(long)indexpath.row);
NSNumber *minValue = [array valueForKeyPath:#"#min.doubleValue"];
NSLog(#"The minValue is %#",minValue);
NSString *str1 = [NSString stringWithFormat:#"%#",minValue];
NSInteger path1 = [array indexOfObject:str1];
NSIndexPath *indexPath1 = [NSIndexPath indexPathForItem:path1 inSection:0];
NSLog(#"Min Value =%# and index = %ld",minValue,(long)indexPath1.row);
}