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Center a boundary of polygons in Google Maps

I am trying to find a better way to center my google map.
I've already written code to add in Markers to Outline and area squarely of which is being store in an array: Coords[i], in-which when returning to the map after save, it centers the map window based on the "first marker" lat/lng coordinates Coords[0].
I am trying to figure out a better way to center the map where there is adequate space around my outline area.
I've try doing it on Dragend, which works somewhat:
google.maps.event.addListener(this.map, 'dragend', function(mapEvent) {
var lat = mapEvent.getCenter() .lat(),
lng = mapEvent.getCenter() .lng(),
console.log(lat + " " + lng + " " + this);
});
But it keeps throwing an error saying:
"Unable to get property 'getCenter' of undefined or null reference"
Can someone tell me what I am doing wrong OR tell be a better way to achieve what I'm trying to do?
As, another option
It would be nice if possible if I can keep the first marker [0] the centering marker as it is already, But don't allow it to outline... just the markers 1 + and on .... But I don't know how to modify my code to do that.
Just looking for a solution that works.
My complete Code is here:
http://pastiebin.com/embed/593d6d809e2f0

You can use a LatLngBounds object. Loop through your Polygons if you have more than one and extend your bounds object with each path coordinates.
LatLngBounds
You can then make your map fit the bounds object so it will zoom and center accordingly by using map.fitBounds().
fitBounds
If you use multi-paths Polygon, make sure you use getPaths method instead of getPath as in the code below.
function initialize() {
var mapOptions = {
zoom: 4,
center: new google.maps.LatLng(0, 0),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
var polygon = new google.maps.Polygon({
editable: true,
strokeOpacity: 0,
strokeWeight: 0,
fillColor: '#00FF00',
fillOpacity: .6,
paths: [
new google.maps.LatLng(39, 4),
new google.maps.LatLng(34, 24),
new google.maps.LatLng(43, 24),
new google.maps.LatLng(39, 4)],
map: map
});
// Create the bounds object
var bounds = new google.maps.LatLngBounds();
// Get paths from polygon and set event listeners for each path separately
polygon.getPath().forEach(function (path, index) {
bounds.extend(path);
});
// Fit Polygon path bounds
map.fitBounds(bounds);
}
initialize();
#map-canvas {
height: 200px;
}
<div id="map-canvas"></div>
<script src="https://maps.googleapis.com/maps/api/js"></script>

Ok I just figured out a way!
I simply grabbed the lat/lng coordinates of the center of the polygon drawn and centered my whole map with that.
var bounds = new google.maps.LatLngBounds();
var i;
//Get Center of Saved Coordinates of the drawn polygons
for (var i = 0; i < values["coords"].length; i++) {
bounds.extend(values["coords"][i]);
}
var movemaplat = bounds.getCenter().lat();
var movemaplng= bounds.getCenter().lng();
console.log("MY MAP CENTER " + movemaplat + ", " + movemaplng);
Thanks to #Daniel Vassallo's answer here: How to get the center of a polygon in google maps v3?

Measuring distance between two points using google api

I'm trying to measure the distance between a marker and a point that has been searched for by postcode. The idea is to make markers appear within a certain radius. as far as I can tell I've done it right but clearly not.
The current code for the function looks like this:
function setup_map(latitude, longitude) {
var _position = new google.maps.LatLng(latitude, longitude);
var mapOptions = {
zoom: 14,
center: _position
}
var map = new google.maps.Map(document.getElementById('map'), mapOptions);
#foreach (var i in ViewData.Model)
{
<text>
var markerPos = {lat: #i.Lat, lng:#i.Long}
var distance = google.maps.geometry.spherical.computeDistanceBetween(markerPos, _position);
var marker = new google.maps.Marker
({
position: new google.maps.LatLng (markerPos),
map: map,
title: "" + (#i.id),
});
</text>
}
}
This function reloads the map and all the markers on it. At the minute I'm not too concerned with loading the markers within the radius. I just want to load them all.
When you click the search button, the map loads to the postcode entered but doesn't load any markers. If I remove the "var distance" line, it still goes to the postcode and loads all of the markers. So by process of elimination, there must be something wrong with this line but I have no idea what.

FusionTables query not returning anything

I'm trying to use Javascript to query a specific state so that only that state appears as a Fusion table on a Google Map. Here is the Javascript that doesn't work:
var chicago = new google.maps.LatLng(41.850033, -87.6500523);
map = new google.maps.Map(document.getElementById('map_canvas'), { center: chicago, zoom: 4, mapTypeId: 'roadmap'});
var layer = new google.maps.FusionTablesLayer(531237, { query:"select geometry from 531237 where state_abbr = 'IL'"});
layer.setMap(map);
If I remove the where clause from the query, all states are returned...as expected. Anyone know what I'm doing wrong when all I want to do is grab the single state?

Turns out that the columns need to be the exact case. Here's the working code:
var layer = new google.maps.FusionTablesLayer(531237, { query:"select geometry from 531237 WHERE STATE_ABBR in ('AL', 'WI', 'CT') "});

Google Map API v3 - Invalid value for property <zoom>

Using Google Maps API v3, I’m trying to do something like below to set zoom. The problem is this would give:
Error: Invalid value for property <zoom>: 10
Any help appreciated, thanks.
var mapInfo = [ [-34.397],[150.644],[10] ];
function initialize() {
var latlng = new google.maps.LatLng(mapInfo[0],mapInfo[1]);
var mapZoom = mapInfo[2];
var myOptions = {
zoom: mapZoom,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
}

Change
var mapInfo = [ [-34.397],[150.644],[10] ];
to
var mapInfo = [-34.397, 150.644, 10];
Then your code should work.
The problem was that what you had was an array of arrays. The square brackets denotes an array so you were passing a array that contained the value instead of value the value itself.

var mapZoom = mapInfo[0][2];

Google Maps v3 API Extend Bounds. Javascript How-To?

function initialize(){
// Creating a map
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 10,
center: new google.maps.LatLng(53.0123601276819, -2.44519164333635),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var m = [];
function addMarker(title, lat, lng) {
m[m.length] = new google.maps.Marker({
position: new google.maps.LatLng(lat, lng),
map: map,
title: title,
clickable: true,
icon: 'http://domain.com/MVC/images/full.png'
});
}
addMarker('Home', 53.0682143712504, -2.52150736731894);
addMarker('Away', 53.0123601276819, -2.44519164333635);
addMarker('Away', 59.0123601276819, -2.44519164333635);
// Create a LatLngBounds object
var bounds = new google.maps.LatLngBounds();
for (var i = 0; i < m.length; i++) {
// Insert code to add marker to map here
// Extend the LatLngBound object
bounds.extend(m[i]);
}
alert(m[0]);
map.fitBounds(bounds);
document.write(getBounds());
}
The above is my code.
My intentions are to develop a map which shows numerous markers and pans the zoom such that all the markers fit on my screen.
I am new to JS.
My understanding is that
var m = [];
creates an empty array.
Then everytime i call addMarker() the details get added to this array m
At the top I set a default zoom and center point.
I then add various markers.
I then loop through each key in the m array and extend the bounds using the data from this.
It is then my understanding that map.fitBounds(bounds); should redefine the zoom/center as applicable to fit all the markers.
It does not.
All my markers show, but the zoom/center is not auto adjusting as such, and I have no idea why.
Any advice would be greatly appreciated.
Thanks

You need to pass a LatLng object to the bounds.extend function.
Here is the code :
....
bounds.extend(new google.maps.LatLng(lat, lng));
....

Here is a clarification of the above answer which is correct except it's missing a parenthesis and a little brief.
//make an empty bounds variable
var bounds = new google.maps.LatLngBounds();
//do your map stuff here
//special note: make sure your lat and lng are floats or googleMaps will error
var lat = 38.103;
var lng = -121.572;
bounds.extend(new google.maps.LatLng(lat, lng));
//adjust the viewport of the map
//special note: this only needs to be done once, don't put it in a loop
map.fitBounds(bounds);