I wanted to post the complete solution to my problem that was due to the strings as Dan mentioned.
I also had to transform the date. This one works:
var datenausdb = [
["2013-08-05","100.0000","100.0000","99.9700"],
["2013-08-06","100.0000","101.0000","100.5000"],
["2013-08-07","101.1200","101.1200","101.1000"],
["2013-08-08","100.0100","100.0100","100.0100"],
["2013-08-09","99.9700","99.9700","99.9700"],
["2013-08-12","100.0000","100.0000","100.0000"],
["2013-08-13","101.0000","101.0000","102.0000"],
["2013-08-14","101.1200","101.1200","102.5000"],
["2013-08-15","100.0100","100.0100","100.0100"],
["2013-08-16","99.9700","99.9700","99.9700"],
["2013-08-19","100.5000","100.5000","100.5000"],
["2013-08-20","101.1000","101.1000","101.1000"],
["2013-08-21","102.0000","102.0000","99.9700"]
];
for (var k = 0; k < datenausdb.length; k++){
datenausdb[k][0] = new Date(datenausdb[k][0]);
}
for (var i = 0; i < datenausdb.length; i++){
for (var j = 1; j < datenausdb[i].length; j++) {
datenausdb[i][j] = parseFloat(datenausdb[i][j]);
}
}
$(document).ready(function () {
g1 = new Dygraph(
document.getElementById("div1"),
datenausdb,
{
showRangeSelector: true,
rangeSelectorHeight: 50,
}
);
}
);