Google Pie Chart is not showing any slices but others

Question

I'm working with google visualization charts and I've got the following problem.

I've got a page were the charts are displayed. It's possible to switch between different charts. Every chart option works, except for the piechart.

The PieChart is visible but it just is a grey circle showing 100%.

The data i've got in the DataTable is:

{"cols": [{
            "id": "New jobs",
            "label": "New jobs",
            "pattern": "",
            "type": "string"
        },
        {
            "id": "Date",
            "label": "Date",
            "pattern": "",
            "type": "number"
        }
    ],
    "rows": [{"c": [{
                    "v": "01-11-2012",
                    "f": null
                },{
                    "v": "5",
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "02-11-2012",
                    "f": null
                },{
                    "v": "3",
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "03-11-2012",
                    "f": null
                },{
                    "v": "8",
                    "f": null
                }]
        },{"c": [{
                    "v": "04-11-2012",
                    "f": null
                },
                {
                    "v": "2",
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "05-11-2012",
                    "f": null
                },
                {
                    "v": "6",
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "06-11-2012",
                    "f": null
                },
                {
                    "v": "7",
                    "f": null
                }
            ]
        }
    ]
}

Maybe there is something wrong with the JSON format.

Please let me know if you want more information or if you have an possible answer.

Answer 1

The problem has been solved.

The value was a string and it had to be a number so in PHP just cast the value to an int and then put it into the array.

{"cols": [{
            "id": "New jobs",
            "label": "New jobs",
            "pattern": "",
            "type": "string"
        },
        {
            "id": "Date",
            "label": "Date",
            "pattern": "",
            "type": "number"
        }
    ],
    "rows": [{"c": [{
                    "v": "01-11-2012",
                    "f": null
                },{
                    "v": 5,
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "02-11-2012",
                    "f": null
                },{
                    "v": 3,
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "03-11-2012",
                    "f": null
                },{
                    "v": 8,
                    "f": null
                }]
        },{"c": [{
                    "v": "04-11-2012",
                    "f": null
                },
                {
                    "v": 2,
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "05-11-2012",
                    "f": null
                },
                {
                    "v": 6,
                    "f": null
                }
            ]
        },{"c": [{
                    "v": "06-11-2012",
                    "f": null
                },
                {
                    "v": 7,
                    "f": null
                }
            ]
        }
    ]
}