Ionic emulate ios error 1

Nishant:example1 nishantmshah$ ionic emulate ios
Running command: /Users/nishantmshah/ionicApps/example1/hooks/after_prepare/010_add_platform_class.js /Users/nishantmshah/ionicApps/example1
add to body class: platform-ios
Running command: /Users/nishantmshah/ionicApps/example1/platforms/ios/cordova/run --emulator
ios-sim was not found. Please download, build and install version 3.0.0 or greater from https://github.com/phonegap/ios-sim into your path. Or ‘npm install -g ios-sim’ using node.js: http://nodejs.org
Error: /Users/nishantmshah/ionicApps/example1/platforms/ios/cordova/run: Command failed with exit code 2
at ChildProcess.whenDone (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/cordova/superspawn.js:131:23)
at emitTwo (events.js:87:13)
at ChildProcess.emit (events.js:172:7)
at maybeClose (internal/child_process.js:818:16)
at Process.ChildProcess._handle.onexit (internal/child_process.js:211:5)
Nishant:example1 nishantmshah$

I am getting the above error when I run ionic emulate ios I did run npm install -g ios-sim still the same error persists.