NSString: fastes way of splitting - iphone

my question is a performance question.
I need to split a huge NSString into coordinates. The string has this format:
#"coordx,coordy coordx,coordy coordx,coordy (...)"
My method to parse this is:
-(NSMutableArray*) parsePath:(NSString*) pathString
{
// first split between the coordinates
NSArray* path = [pathString componentsSeparatedByString:#" "];
NSMutableArray* coords = [[NSMutableArray alloc] init];
static NSString *seperator = #",";
NSArray *coord;
for(NSString *coordString in path)
{
coord = [coordString componentsSeparatedByString:seperator];
Coordinate *c = [[Coordinate alloc]init];
c.x = [[coord objectAtIndex:0] intValue];
c.y = [[coord objectAtIndex:1] intValue];
[coords addObject:c];
[c release];
}
return coords;
}
So, is there any way to make this faster?
Thanks!
Sebastian

Using NSScanner is probably faster.
http://developer.apple.com/iphone/library/documentation/cocoa/reference/Foundation/Classes/NSScanner_Class/Reference/Reference.html

Related

Extracting Unique Objects from a Data Array

I want to add names in a data array only if the name does not previously exist in the data array. When I attempt to print these names, I do get repetitions. Is there a way to solve this?
-(NSMutableArray *)autoComplete
{
NSMutableArray *dataArray = [[NSMutableArray alloc] init];
NSString *url = [NSString stringWithFormat:#"%#45.25,-95.25&limit=100&client_id=Von0J4Bu6INiez5bGby2R&client_secret=50sUjSbg7dba8cQgtpdfr5Ns7wyYTqtmKpUU3khQ",kWSURL];
NSDictionary * returnDict = (NSDictionary *) [self callWebService:url];
if([returnDict objectForKey:#"success"])
{
NSArray *responceArray = [returnDict objectForKey:#"response"];
for (NSDictionary *dict in responceArray) {
placeDC *place = [[placeDC alloc]init];
NSDictionary *placeDict = (NSDictionary *)[dict objectForKey:#"place" ];
NSDictionary *loctionDict =(NSDictionary *)[dict objectForKey:#"loc"];
NSString * name =[placeDict objectForKey:#"name"];
NSString * stateFull =[placeDict objectForKey:#"stateFull"];
NSString * countryFull =[placeDict objectForKey:#"countryFull"];
NSString *latitude =[loctionDict objectForKey:#"lat"];
NSString *longitude = [loctionDict objectForKey:#"long"];
place.placeNmae=name;
place.countryFullName=countryFull;
place.stateFullName=stateFull;
NSLog(#"%# ",stateFull);
place.latitude=[latitude doubleValue];
place.longitude=[longitude doubleValue];
[dataArray addObject:place];
}
}
return dataArray;
}
First Check that is there any response from the Server side or not, to check response use NSLog() or Break Points.
if response is ok then put a the following check your code
if (![dataArray containsObject:#"Some Name"])
{
// add Object
}
You could add the name NSString to an NSSet and check in every cycle whether it contains it or not.
Inside your if you could write something like:
NSArray *responceArray = [returnDict objectForKey:#"response"];
NSSet *names = [[NSSet alloc] init];
for (NSDictionary *dict in responceArray) {
NSDictionary *placeDict = (NSDictionary *)[dict objectForKey:#"place" ];
NSString * name =[placeDict objectForKey:#"name"];
if (![names containsObject:name]) {
[names addObject:name];
placeDC *place = [[placeDC alloc]init];
NSDictionary *loctionDict =(NSDictionary *)[dict objectForKey:#"loc"];
NSString * stateFull =[placeDict objectForKey:#"stateFull"];
NSString * countryFull =[placeDict objectForKey:#"countryFull"];
NSString *latitude =[loctionDict objectForKey:#"lat"];
NSString *longitude = [loctionDict objectForKey:#"long"];
place.placeNmae=name;
place.countryFullName=countryFull;
place.stateFullName=stateFull;
NSLog(#"%# ",stateFull);
place.latitude=[latitude doubleValue];
place.longitude=[longitude doubleValue];
[dataArray addObject:place];
}
}
Hope this helps!
Do one thing, add your dict in another array and search in this array that data already exist or not,
[tempAry addObject: dict];
and before insertion
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"name == %#", name];
NSArray *filteredArray = [tempAry filteredArrayUsingPredicate:predicate];
if ([filteredArray count] == 0)
{
[dataArray addObject:place];
}
else{
//Already exist
}
Why don't you create a separate dictionary, as an ivar or property of you class, for storing our required value, say it as :
NSMutableDictionary *uniqueValueDict=[NSMutableDictionary new];
And keep storing your required value and key as:
[uniqueValueDict setObject:stateFull forKey:uniqueValueDict];
Your work will be done.
This is the easiest solution that i have applied and this should get you going in picking up unique elements out of array.
NSArray * claimedOfferArray = [[NSArray alloc]initWithObjects:#"A",#"B",#"A",#"C",#"B" nil];
NSArray * distinctArray = [[NSArray alloc]init];
distinctArray =[[NSSet setWithArray:claimedOfferArray] allObjects];
This code will also work with NSMutableArray
Let me know if it works for you..:).

How to add elements to an array created by a 'for' loop ?

I am using for loop for get distance from current location to destination location. I would like an array that contains all distances from current to destination location.
for (i = 0; i < [Arr_Lat count]; i++)
{
NSString *latst1 = [[NSString alloc]initWithFormat:[Arr_Lat objectAtIndex:i]];
NSString *longst1 = [[NSString alloc]initWithFormat:[Arr_Long objectAtIndex:i]];
NSLog(#"First lat : %#",latst1);
NSLog(#"First ong : %#",longst1);
double Doblat1 = [latst1 doubleValue];
double Doblong1 = [longst1 doubleValue];
CLLocationCoordinate2D coord1 = CLLocationCoordinate2DMake(coord1.latitude = Doblat1, coord1.longitude = Doblat1);
NSLog(#" Coordinat ==== : %f -- %f",coord1.latitude,coord1.longitude) ;
CLLocation *currLoc = [[CLLocation alloc] initWithLatitude:appDel.curr_lat longitude:appDel.curr_long];
CLLocation *destLoc1 = [[CLLocation alloc] initWithLatitude:Doblat1 longitude:Doblong1];
NSLog(#" Currennt Location : %#", currLoc);
NSLog(#" Destination Location : %#" , destLoc1);
distance = [destLoc1 distanceFromLocation:currLoc];
NSLog(#" Distance : ------- %0.3f", distance);
DistStr = [[NSString alloc]initWithFormat:#" %f",distance];
[currLoc release];
[destLoc1 release];
[Arr_title retain];
[tbl_nearplace reloadData];
}
If you want to store the distance you need an NSMutableArray.
Declare a NSMutableArray *distanceArray; in class scope.
Initialize it: distanceArray = [[NSMutableArray alloc] init];
In the for loop after DistStr =[[NSString alloc]initWithFormat:#" %f",distance];
write the following code:
[distanceArray addObject:DistStr];
Say we have this array with stuff we want to iterate over and add those items to another array
NSArray *someArrayWithStuff = #[#"Hello",
#"Its",
#"Very",
#"Cold",
#"Outside",
#"Today"];
Say we want the content of someArrayWithStuff to be added to this other array so we create an NSMutableArray
NSMutableArray *theNewArrayWithOurStuff = [NSMutableArray array];
We loop through the someArrayWithStuff
for (int i = 0; i < someArrayWithStuff.count; i++) {
// Add object to the new array
[theNewArrayWithOurStuff addObject:[someArrayWithStuff objectAtIndex:i]];
}
NSMutableArray *Distance=[[NSMutableArray alloc]Init];
for (i = 0; i < [Arr_Lat count]; i++)
{
NSString *latst1 = [[NSString alloc]initWithFormat:[Arr_Lat objectAtIndex:i]];
NSString *longst1 = [[NSString alloc]initWithFormat:[Arr_Long objectAtIndex:i]];
NSLog(#"First lat : %#",latst1);
NSLog(#"First ong : %#",longst1);
double Doblat1 = [latst1 doubleValue];
double Doblong1 = [longst1 doubleValue];
CLLocationCoordinate2D coord1 = CLLocationCoordinate2DMake(coord1.latitude = Doblat1, coord1.longitude = Doblat1);
NSLog(#" Coordinat ==== : %f -- %f",coord1.latitude,coord1.longitude) ;
CLLocation *currLoc = [[CLLocation alloc] initWithLatitude:appDel.curr_lat longitude:appDel.curr_long];
CLLocation *destLoc1 = [[CLLocation alloc] initWithLatitude:Doblat1 longitude:Doblong1];
NSLog(#" Currennt Location : %#", currLoc);
NSLog(#" Destination Location : %#" , destLoc1);
distance = [destLoc1 distanceFromLocation:currLoc];
NSLog(#" Distance : ------- %0.3f", distance);
NSString *DistStr = [[NSString alloc]initWithFormat:#" %f",distance];
[Distance addObject:DistStr];
[DistStr release];
[currLoc release];
[destLoc1 release];
[Arr_title retain];
[tbl_nearplace reloadData];
}

How to display x raise to y in UIlabel

how can I display 5 raise to 1/3 in iphone i.e I want 1/3 written above 5 can anyone help please
I Found this solution, hope so it would be helpful for you.
x to the power of y in a UILabel could be easy. Just replace your indices with unicode superscript characters... I use the following method to turn an integer into a string with superscript characters.
+(NSString *)convertIntToSuperscript:(int)i
{
NSArray *array = [[NSArray alloc] initWithObjects:#"⁰", #"¹", #"²", #"³", #"⁴", #"⁵", #"⁶", #"⁷", #"⁸", #"⁹", nil];
if (i >= 0 && i <= 9) {
NSString *myString = [NSString stringWithFormat:#"%#", [array objectAtIndex:i]];
[array release];
return myString;
}
else {
NSString *base = [NSString stringWithFormat:#"%i", i];
NSMutableString *newString = [[NSMutableString alloc] init];
for (int b = 0; b<[base length]; b++) {
int temp = [[base substringWithRange:NSMakeRange(b, 1)] intValue];
[newString appendString:[array objectAtIndex:temp]];
}
[array release];
NSString *returnString = [NSString stringWithString:newString];
[newString release];
return returnString;
}
}
Try this NSString *cmsquare=#"cm\u00B2";
It will display cm².
Yes you can do that but you need custom UILabel, either Make it by yourself or Get it Open Source..

how to create an array of string or float in Objective-C

i need some help here, i need to know how to create an array of string retrieved from an array. i'm using powerplot for graph and it only accept float or string array.
i need to create something something like this dynamically.
NSString * sourceData[7] = {#"2", #"1", #"4", #"8", #"14", #"15", #"10"};
Below are my code to find out the numbers in strings.
NSInteger drunked = [appDelegate.drinksOnDayArray count];
NSMutableArray * dayArray = [[NSMutableArray alloc] init];
NSMutableArray * sdArray = [[NSMutableArray alloc] init];
//float *sdArray[7];
for (int i=0; i<drunked; i++) {
DayOfDrinks *drinksOnDay = [appDelegate.drinksOnDayArray objectAtIndex:i];
NSString * dayString= [NSDate stringForDisplayFromDateForChart:drinksOnDay.dateConsumed];
[dayArray addObject:dayString];
NSLog(#"%#",[dayArray objectAtIndex:i]);
drinksOnDay.isDetailViewHydrated = NO;
[drinksOnDay hydrateDetailViewData];
NSString * sdString= [NSString stringWithFormat:#"%#", drinksOnDay.standardDrinks];
[sdArray addObject:sdString];
NSString *tempstring;
NSLog(#"%#",[sdArray objectAtIndex:i]);
}
thanks for the help :)
Array's in Objectice-C aren't that hard to work with:
NSMutableArray *myArray = [NSMutableArray array];
[myArray addObject:#"first string"]; // same with float values
[myArray addObject:#"second string"];
[myArray addObject:#"third string"];
int i;
int count;
for (i = 0, count = [myArray count]; i < count; i = i + 1)
{
NSString *element = [myArray objectAtIndex:i];
NSLog(#"The element at index %d in the array is: %#", i, element); // just replace the %# by %d
}
You can either use NSArray or NSMutableArray - depending on your needs, they offer different functionality.
Following tutorial covers exactly what you are looking after:
http://www.cocoalab.com/?q=node/19
You can also add the elements to the array when you init (and optionally add them later only if you are using the Mutable version of a collection class:
NSMutableArray *myArray = [[NSMutableArray alloc] initWithObjects:#"2", #"1", #"4", #"8", #"14", #"15", #"10", nil];
[myArray addObject:#"22"];
[myArray addObject:#"50"];
//do something
[myArray release];
You can use malloc to create a C-style array. something like this should work:
NSString **array = malloc(numElements * sizeof(NSString *))
some code here
free(array)
Be aware that unlike NSMutable array, c arrays won't do a retain, so you have to manage it if needed. And don't forget the free

distance from CurrentLocation to data from Plist File

I have a long list of places with Latitudes and Longitudes in a plist. I want to show a tableView of the places only within X distance of the user's current location. Is there a way to create objects from the lats & longs in the plist file so I can use 'distanceFromLocation'? More importantly, how do I get the array to only display the names with a distance from current less than X? I'm assuming I would need to make a series of objects from lats & longs in the plist, then do an objects in array if objects distanceFrom is less than X, correct?
Please help.
Here's where I am now: I get an error on the double clubLatitude line
- (void)viewDidLoad {
[super viewDidLoad];
NSArray *clubArray = [NSArray arrayWithObjects:[self danceClubLocation], nil];
self.tableData = clubArray;
}
-(CLLocation *)danceClubLocation
{
NSString *plistPath = [[NSBundle mainBundle] pathForResource:#"Data" ofType:#"plist"];
NSArray *array = [NSArray arrayWithContentsOfFile:plistPath];
NSEnumerator *e = [array objectEnumerator];
id object;
while ((object = [e nextObject])) {
double clubLatitude = [[array valueForKey:#"Latitude"] doubleValue];
double clubLongitude = [[array valueForKey:#"Longitude"] doubleValue];
CLLocation *clubLocation = [[CLLocation alloc] initWithLatitude:clubLatitude longitude:clubLongitude];
if ([clubLocation distanceFromLocation:myLocation]<=50) {
return clubLocation;
}
else return nil;
}
return nil;
}
-(CLLocation *)myLocation
{
CLLocation *location = [locationManager location];
CLLocationCoordinate2D coordinate = [location coordinate];
NSNumber *myLatitude = [NSNumber numberWithDouble:coordinate.latitude];
NSNumber *myLongitude = [NSNumber numberWithDouble:coordinate.longitude];
double myLatitudeD = [myLatitude doubleValue];
double myLongitudeD = [myLongitude doubleValue];
myLocation = [[CLLocation alloc]initWithLatitude:myLatitudeD longitude:myLongitudeD];
return myLocation;
}
As #DavidNeiss said, you have to iterate over the list (an NSArray with the plist as source) and it would be something like this:
NSString *plistPath = [[NSBundle mainBundle] pathForResource:#"latlong" ofType:#"plist"];
NSArray *array = [NSArray arrayWithContentsOfFile:plistPath];
NSEnumerator *e = [array objectEnumerator];
id object;
while (object = [e nextObject]) {
// do something with object
}
Then you can do what you want (removing what's far from the user or whatever).
Read in your plist, iterate over it to pull out ones within X distance and populate any array with them that will be the data source for your table view?